Polaroid: A Chemical, Mechanical and Optical Miracle

[00:00:01]If you haven't seen a Polaroid SX-70 before, this will look like magic.

[00:00:07]This camera was made in 1973.

[00:00:10]In 10 minutes, we'll have a self-developed color photo.

[00:00:15]Let's find out how it works.

[00:00:27]After spending the last 6 months making videos largely about all the many and varied schemes humanity has devised to nuke itself out of existence, this one is a refreshing change.

[00:00:38]In some ways, the videos about things you can go and buy on eBay right now and enjoy yourself and my favorite ones to make. Nothing beats actually getting hands-on with the topic of discussion.

[00:00:48]But, don't let the accessibility fool you.

[00:00:51]In this little plastic envelope is some of the most advanced chemical engineering available to the public.

[00:00:57]In fact, I want to go straight into this video by stressing that although Polaroid cameras are fantastic fun and have brought joy to millions over the decades, until the 21st century, they were largely used as scientific and commercial tools.

[00:01:11]In fact, they've made cameos in multiple previous videos by me.

[00:01:15]To get a taste of it, let's look at some use cases I've come across in the wild.

[00:01:20]Here are researchers from the Canadian Defense Research Board in 1964 permanently recording oscilloscope readings using a Polaroid camera following the test detonation of 500 tons of high explosives, the largest controlled non-nuclear detonation in history.

[00:01:37]Here is the setup used by engineers at Rocketdyne in the late 1960s to record atomization of molten lithium through injection nozzles for their tripropellant rocket engine.

[00:01:47]Those of you who have watched that video will have seen me lamenting about how badly the photographs from the technical reports had been reproduced by photocopying.

[00:01:55]They should have used the kit Polaroid used to to add to your camera, which would eliminate that problem.

[00:02:01]Half-tone filters that allowed Polaroid photos to be reproducible in photo copied documents.

[00:02:07]This Polaroid camera was used to take passport photos. Four at once.

[00:02:12]It resulted in the company pulling sales from South Africa after they discovered it was used to create identification documents used for racial segregation as part of apartheid.

[00:02:23]Broadly related, if you've seen my video linked on screen.

[00:02:26]Here is that oscilloscope attachment again, this time being used to record results from bang meters, which are used by orbiting satellites to detect nuclear detonations.

[00:02:36]One of the actual cameras we'll see in this video was used by a viewer's great-grandfather.

[00:02:42]He was a union safety rep who used it to take on-site photos to show to the foreman.

[00:02:47]I used to use a special intrinsically safe digital camera on-site in my first job for similar purposes, and I cannot stress how useful it was.

[00:02:56]Bit of a sad one. Here are the crew of STS-51L, the final flight of Challenger, having their pre-flight press photo taken and receiving their own Polaroid version.

[00:03:07]I'd love to know what happened to that photo, actually.

[00:03:10]Here is the sun in extreme UV light.

[00:03:13]This was recorded on Skylab in 1973 using a dedicated spectroheliograph.

[00:03:18]Astronauts would periodically photograph this monitor with a Polaroid SX-70 so they could record changes over time.

[00:03:25]And a fictional use case, yet possibly the most famous one, the excellent movie Memento, where a Polaroid 680 pretty much forms the basis of the entire story.

[00:03:38]There will be countless other realized use cases. Feel free to mention any that you've come across in the comments, but I think we get the point. Until digital cameras came about, this was the only way to create a photo in near real time without a lab.

[00:03:53]Some of the cameras there probably looked unfamiliar.

[00:03:56]What you picture when I say Polaroid camera probably depends on your age.

[00:04:02]Before I got back into film photography 3 years ago, I would have pictured this, the cheap yet perfectly functional camera I got for Christmas when I was 10 years old.

[00:04:12]Many of you may instead picture the incredible SX-70 featured in the intro.

[00:04:18]And some of you will picture an entirely different format altogether, peel-apart film, or maybe even the first iterations of Polaroid cameras, roll film.

[00:04:28]We'll discuss all these formats in this video.

[00:04:31]You'll hear me mentioning the project files throughout this video.

[00:04:36]I've written up some detailed instructions to make some of the things I'm going to make along the way today.

[00:04:41]They're in a GitHub repo at the moment, which is linked in the description.

[00:04:45]If you're watching this far enough in the future, they may be on a website instead.

[00:04:49]I really need to get round to making a website.

[00:04:53]Oh, and as followers of the channel will be aware, this video has been 3 years in the making.

[00:04:59]It started as a video diary of me fixing up a broken SX-70 and adding some modern-day upgrades.

[00:05:05]That was when I had about 100 or so subscribers, and I was due to publish it around July 2023.

[00:05:12]But then some billionaires became data points, and my channel completely blew up, and I ended up focusing on other topics.

[00:05:20]Now, I have so much to talk about, and this topic deserves the full Alexander the OK treatment.

[00:05:27]And just something to ramp up the intrigue, if you're watching this on an iPhone, that iPhone wouldn't exist without this camera.

[00:05:35]Let's find out why.

[00:05:42]As I said, Polaroid film looks like magic.

[00:05:46]I want to make really clear from the start it's not.

[00:05:50]My aim today is to walk you through the process and in an hour you'll not only understand it, but hopefully appreciate how it's somehow reasonably simple, yet incredibly clever at the same time. I always say Polaroid cameras feel like something that was invented in the 1980s, not the 1940s.

[00:06:08]But to get to that point, we need to start in the 70s.

[00:06:11]The 1870s.

[00:06:14]Given silver halide photography is one of the most important chemical processes ever discovered, there are countless excellent in-depth guides available online which explain the full details of how it works.

[00:06:26]Of course, I would recommend the one by Technology Connections.

[00:06:29]You guys are all subscribed to Technology Connections, right?

[00:06:33]Today, as always, I'll explain just the broad details whilst giving a practical demonstration. First of all, a camera.

[00:06:41]Let's just use a more conventional one for now.

[00:06:44]A camera is just a dark box with a lens on the front.

[00:06:47]The lens focuses the light onto the back wall.

[00:06:51]Here I've replaced the back wall with a ground glass plate, so you can see the focused image.

[00:06:56]When we take a photo, a shutter opens in the back wall and exposes the film.

[00:07:01]For a split second, the image is projected onto a section of the film until the shutter closes again.

[00:07:08]Film. That's mainly what this video is about. What even is film?

[00:07:13]It's a plastic strip coated on one side with gelatin.

[00:07:17]Oh, and by the way, it seems amazing, but nobody has ever found anything better than gelatin to use for the binding agent.

[00:07:25]I suppose that is a shame for vegetarians, but that's just the reality, I suppose.

[00:07:30]Suspended in that layer of gelatin are tiny crystals of silver halide.

[00:07:35]And those crystals are the magic part.

[00:07:38]Expose a crystal of silver halide to enough light, and an area of imperfection in the crystal lattice will turn into metallic silver. Just a few atoms of silver, mind you. The higher the total flux of light shown onto a collection of silver halide crystals, the more of them will form these tiny specs of silver.

[00:07:58]Do this for our image on an entire section of film, and we've just produced a latent image.

[00:08:05]We can't see it.

[00:08:06]Even if we tried, we'd instantly erase it as all the incoming light would convert all the crystals on the exposed film.

[00:08:13]But, we can use it to produce our final image.

[00:08:17]My chemistry teacher in sixth form college described the ability of silver halide to form latent images as one of the most fortuitous coincidences in chemistry. Okay, I have a film here which I've taken some photos on. Let's develop it.

[00:08:31]Unfortunately, I can't show you this part directly as it's done in total darkness in this light-safe container.

[00:08:38]But, you'll get to see the final images being developed in real time soon.

[00:08:42]We first immerse the film in a developer solution.

[00:08:46]Now, the incoming light previously reduced a tiny portion of some of those crystals to silver.

[00:08:52]The developer chemicals are specifically formulated to reduce silver halide into silver.

[00:08:58]But, they do it slowly over the course of a few minutes.

[00:09:03]The halide crystals with the small seed zones of atomic silver will be converted to silver faster than the crystals that are unexposed.

[00:09:12]So, by immersing the film in this solution for the correct amount of time, just the light-exposed crystals will become solid silver particles.

[00:09:22]We wash off the developer solution inside the light-proof developing tank.

[00:09:27]And in there, right now, is a film containing all of our images rendered in silver particles.

[00:09:34]But, we can't look at them.

[00:09:36]Again, if we tried, the light would begin converting all the unexposed crystals into silver as well.

[00:09:42]We need to somehow remove those unexposed crystals.

[00:09:47]So, we add a fixing solution to the tank.

[00:09:51]This is a chemical, usually sodium thiosulfate, that dissolves silver halide, but not solid silver.

[00:09:59]So, we're left with our image fixed forever in place as tiny silver particles in gelatin on the surface of the film.

[00:10:07]There's two problems here, though.

[00:10:10]Problem number one, this is a tiny image.

[00:10:13]And problem number two, silver appears black in this form.

[00:10:18]Remember the areas where silver particles formed the most, those that were brightest in the original exposure?

[00:10:24]Yes, this is a negative image. To convert it to our final image, we use one of these, an enlarger.

[00:10:32]I got mine for just 20 pounds on eBay.

[00:10:34]It folds into a briefcase, so not only does it take up less room in my house, but I also get to feel like a spy when I use it. Oh, and this one was made in the Soviet Union.

[00:10:44]I can't believe I'm saying this, but it's actually really well-built. Okay, enlarging the photograph just involves the same process, but in reverse.

[00:10:52]And I can carry out under a red safe light in a darkroom, so you can see me doing it.

[00:10:57]You know how the lighting is often terrible in my earlier videos?

[00:11:01]Yeah, that's because my office can convert into a darkroom.

[00:11:05]Here is my film negative in the enlarger.

[00:11:08]This thing is basically just a projector. It projects an enlarged version of the image here.

[00:11:13]Photo paper is really just the same thing as photographic film, except instead of being made of plastic, it is paper coated with a layer of gelatin containing silver halide crystals.

[00:11:24]We place a piece of the photo paper on the bed and expose it for a few seconds.

[00:11:29]Okay, that just repeated what happened inside the camera. The silver halide crystals exposed to light have developed spots of atomic silver and formed a latent image.

[00:11:38]So, let's develop that image. We put the paper in a developer solution like this.

[00:11:43]And this is the part you've seen in crime detective thrillers.

[00:11:47]It feels exciting every time I do it.

[00:11:49]And there we go. The exposed halide is converted to silver.

[00:11:54]Wash it off, pop it in the fixer solution for a couple of minutes. That dissolves the unexposed halide. And that is our image permanently fixed in place.

[00:12:04]We turn the lights back on and job done.

[00:12:07]How on earth do we do all that without a lab in broad daylight?

[00:12:18]Let's come back to the in broad daylight part later.

[00:12:22]To get rid of the lab, it's about time we introduce the first of the heroes in today's story, Edwin Land, the co-founder of Polaroid.

[00:12:32]Of course, the process was developed by hundreds of scientists over the years, but Land was very much the driving force behind the success of Polaroid both due to his technical capability and some rather impressive salesmanship.

[00:12:46]Let's look at the process which all instant photography is based on, silver halide diffusion transfer.

[00:12:53]Now, this wasn't discovered by Land. It was discovered independently by Edith Weyde in Germany and Andre Rott in Belgium in the late 1930s.

[00:13:03]I think that date and location is enough to explain why the process wasn't first commercialized in Europe, but Weyde and Rott later teamed up to write this book, one of the main sources for this video.

[00:13:17]I would love a physical copy, but I couldn't find one anywhere.

[00:13:21]I'm delighted to report it is available via the Internet Archive's Open Library, though.

[00:13:27]So, let's start with the film from the last chapter.

[00:13:30]Just regular silver halide in gelatin film, nothing special here.

[00:13:36]Recall how after exposing the film and forming a latent image on it, we'd submerge it in developer solution to develop a visible negative image, and then you fix it to make that image non-sensitive to light.

[00:13:49]It's possible to do both of those steps at the same time using a single solution.

[00:13:55]In fact, I have my very own formula I came up with myself for a mono developer. We start by mixing the developer and fixer together.

[00:14:03]Now, this wouldn't work by itself. The fixer would probably dissolve away most of the silver halide before the developer had a chance to convert it to elemental silver.

[00:14:12]So, we add some sodium hydroxide.

[00:14:15]That increases the alkalinity of the solution and delays the action of the fixer, giving the developer a chance to act first.

[00:14:24]I'll go into my darkroom now, cut off a piece exposed film and leave it in this solution for 3 minutes.

[00:14:31]Rinse it off, and there, a negative created with just a single step.

[00:14:36]The image quality is never going to be quite as good as that of a two-step process, but well, as we'll see, it can get pretty close. Soon we'll also see why I have my own mono developer recipe.

[00:14:49]Okay, so this is a great step. In theory, we could put our film sheet in a camera with a little pouch of this mono developer at one end, and a piece of light-proof material behind it, take a photo and pull the whole assembly through a pair of rollers.

[00:15:04]The rollers rupture the developer pouch, spread it over the exposed film, and press the light-proof paper over the top of the film.

[00:15:11]Leave it a couple of minutes, peel the two layers apart, and we'd be left with a developed negative. Not a bad result, but we don't want a negative, we want a positive image.

[00:15:21]Let's take a closer look at the mono developer solution during the fixing process.

[00:15:27]After the negative is developed, areas of the chemical paste above unexposed portions of film will contain a high concentration of dissolved silver ions.

[00:15:37]Remember, the fixing chemical dissolves these ions from the film.

[00:15:42]These appear as light on the negative, but we want them to appear dark on our final image.

[00:15:48]If we could replace that top light-proof sheet with something that causes silver to precipitate out of the solution, we'd create silver particles in these regions, giving us a reversed negative, a positive.

[00:16:02]At its most basic level, this new sheet, or receiver layer, consists of paper with a layer of gelatin, and the gelatin is infused with tiny silver particles, much smaller than the halide grains on the film.

[00:16:17]Side note, these tiny particles are called colloidal silver. Searching for references to colloidal silver was a complete nightmare because people who refuse to take doctors' advice peddle this as a some kind of miracle cure-all substance. In reality, if you drink colloidal silver enough, it will turn you into a Smurf.

[00:16:38]Literally, that is not a joke.

[00:16:41]While I'm ranting about colloids, the photography term for the silver halide in gelatin layers on film is emulsion.

[00:16:48]It does my head in. It's not an emulsion. If anything, it's a colloid.

[00:16:54]I tried to avoid saying emulsion, but I kind of had to eventually to make the script easier to understand. Just know that I call it an emulsion through gritted teeth.

[00:17:04]Anyway, the colloidal silver grains act as nucleation points for the dissolved silver in the mono developer solution.

[00:17:11]Larger grains precipitate out on the receiver surface in locations where there's a higher concentration of dissolved silver.

[00:17:18]Give the whole process a couple of minutes, peel the two layers apart, and there we have it, instant photography.

[00:17:25]This is fantastic, but the process in the late 1930s existed only in a lab. It was unstable and didn't produce a great image.

[00:17:34]This is where Edwin Land came in.

[00:17:37]The prospect of a low or even zero effort developing process for the everyday person became his obsession.

[00:17:44]And in November 1948, the Polaroid Land Camera Model 95 was first sold to the public.

[00:17:51]1948.

[00:17:53]It'll never fail to amaze me, Polaroid film predates the invention of the credit card.

[00:18:00]Absolutely remarkable.

[00:18:02]One of my viewers kindly sent in some footage of them using their great-grandfather's Model 110.

[00:18:08]This was sold a few years after the 95, but uses the same film format, roll film.

[00:18:14]We have two rolls.

[00:18:16]One is the film, the other is the receiver paper, with pouches of developer solution spaced at intervals along the receiver roll.

[00:18:25]After loading the rolls into the camera, a dark slide is pulled through this door, which lines up the first interval of film in front of the lens.

[00:18:33]An image is taken, and the end of the roll is pulled through the door whilst keeping the back of the camera closed.

[00:18:40]As we pull, some clever internal geometry maneuvers the film around the roller, pairs it up with the receiver, and presses the two together via a pair of rollers, which also disperse the chemical pouch between the two sheets.

[00:18:53]Leave for a couple of minutes in the dark interior of the camera to let the development and diffusion transfer take place, then open the outer back door and peel away the film, and there is our image. I will note in this case the image is quite low contrast because this is decades expired film, but well, we'll get to that. And hey, still works.

[00:19:18]A final step for the earlier cameras required manually applying this coating solution which protects the image and prevents it from fading over time.

[00:19:26]You'll have no doubt noticed how beautiful this camera is and how clever the mechanism is.

[00:19:33]We'll come back to clever cameras after we talk more about clever film.

[00:19:42]This chapter is about the best instant film ever produced, peel-apart film.

[00:19:48]And with that, we need to address the elephant in the room.

[00:19:52]Not that elephant, this one.

[00:19:55]Color.

[00:19:56]It's not the 19th century.

[00:19:58]Everything we've discussed so far has been in black and white.

[00:20:02]Understanding black and white photography is firmly in everyone's comfort zone.

[00:20:07]Color film works by the same process, but is a violent step up in practical complexity.

[00:20:13]Let's see how it works.

[00:20:16]You know, if there's something I never appreciated before this video, it's how sensitive and well-developed human vision is.

[00:20:23]Those scenes in the previous chapter in the darkroom, they looked terrible on camera.

[00:20:28]But replace the camera with the human eyeball and I could see perfectly fine and clearly.

[00:20:33]Those black and white photos from earlier only directly trigger the rod cells in your eyes.

[00:20:39]Rod cells detect brightness only, so in principle operate as a black and white sensor array. Cone cells detect color.

[00:20:47]If you have normal color vision, you have three types of them.

[00:20:51]Here is a graph of how strongly each type responds to the visible spectrum.

[00:20:55]So, we could roughly say we have blue sensitive, green sensitive, and red sensitive cells.

[00:21:02]You can therefore make any human perceptible color by mixing the correct proportion of red, green, and blue light. Now, there will be comments about my elementary biology lesson there.

[00:21:13]What about pink and brown?

[00:21:15]Yeah, those are perceived by our brains when we take colors from the spectrum and increase the brightness or decrease it.

[00:21:21]Why is yellow a primary color for paint and not green?

[00:21:25]Why is violet this end at the opposite end to red?

[00:21:29]Those questions and more not answered here because I have no idea.

[00:21:33]Okay, let's see if I can do this without it taking the rest of the video.

[00:21:38]I'm just discussing the basic chemistry here, but the base process is still just the silver halide process from earlier.

[00:21:44]Photography experts watching, I'm aware I'm missing out details. There are sources in the description if you want to know more.

[00:21:51]Let's start with blue light.

[00:21:53]Take a layer of silver halide crystals and coat them with a very thin layer of yellow dye.

[00:21:59]A yellow dye absorbs blue light, but reflects all other light. So, the crystals in this layer will only react and form seed spots when exposed to blue light, which is absorbed by the thin layer of dye and provides the energy to reduce ions in the crystals to solid silver.

[00:22:16]This layer is sensitive to blue.

[00:22:20]Now, place a transparent yellow filter below it.

[00:22:23]This blocks any remaining blue light, but allows green and red to pass through. So, the crystals in the next layer are coated with a magenta dye.

[00:22:32]Magenta absorbs green, but reflects red.

[00:22:36]So, these crystals will only react and form seed spots when exposed to green light.

[00:22:42]This layer is therefore green sensitive.

[00:22:46]Place a magenta filter below to stop any remaining green light from passing.

[00:22:50]Finally, add a layer of crystals coated in cyan dye.

[00:22:54]As you've probably now guessed, cyan absorbs red, but reflects everything else.

[00:22:59]So, this layer is red sensitive.

[00:23:02]As each layer is exposed to its respective color, the exposed silver halide crystals form silver seed spots.

[00:23:10]I'm illustrating that now by turning the crystals gray to make it a little clearer visually.

[00:23:15]Now, we have three stacked latent images. Each records the brightness of one of the three primary colors.

[00:23:23]That is all the information we need to recreate a color image.

[00:23:27]If you're creative, you could maybe think of a way to make some kind of image now just using the developing and fixing chemistry from above.

[00:23:36]But, let's develop it now using the standard color film process.

[00:23:41]As we did earlier, submerge the film in developer solution and reduce the exposed silver halide crystals to solid silver.

[00:23:49]To complete the development in place on the film, we need to introduce a new family of compounds, dye couplers.

[00:23:56]These are droplets dispersed through the film alongside the silver halide crystals.

[00:24:02]Now, when the silver halide was reduced to silver, the nearby developer was oxidized.

[00:24:09]Dye couplers are chemicals formulated to react with oxidized developer.

[00:24:15]Depending on the exact dye coupler used, the resulting product is colored.

[00:24:21]The dye coupler in the top layer is formulated to give a yellow compound after reacting with oxidized developer.

[00:24:28]That in the green layer gives a magenta compound. And that in the red layer gives a cyan compound. In other words, we've just created a negative image.

[00:24:39]But, we don't want the black silver particles anymore. So, a bleaching stage oxidizes them back to silver halide.

[00:24:46]And the same fixing stage as before dissolves these silver halide crystals and washes them away.

[00:24:53]We're left with our three color negative dye layers.

[00:24:57]Now, to invert that negative and get our final image again, I don't think it's too difficult to imagine a modified version of the enlargement process I showed earlier, but with three layers in the photo paper and filtered yellow, cyan, and magenta light.

[00:25:12]But, this isn't a video about that. This is about instant photos. We have a mono developer again that develops the silver halide, activates the dye couplers, and bleaches and fixes the film.

[00:25:23]But, we don't really need the mono developer to do all that.

[00:25:28]Because Polacolor, the original Polaroid color film, was subtly different to conventional color film.

[00:25:34]Let's get rid of the dye developers and replace them instead with colored dyes of the negative primary colors.

[00:25:41]Now, if these are translucent, they'll transmit the light of their respective color.

[00:25:45]So, we don't need the filters anymore.

[00:25:48]We could put the dye layers below each halide layer to act as the filter.

[00:25:54]Now, to each dye molecule, add a chemical group that binds to silver.

[00:25:59]When exposed to the reagent, the dye migrates upwards, but is immobilized in areas where developed silver is in place.

[00:26:06]In other words, areas that were exposed to light of that layer's color.

[00:26:10]These new dye compounds are called dye developers.

[00:26:13]They were arguably the most impressive discovery Polaroid ever made. But, how about the receiver paper? Well, as I understand, it's pretty much the same process as the black and white roll film we already discussed.

[00:26:26]Let's just imagine the blue layer for now.

[00:26:29]Take an area where blue light struck.

[00:26:31]The silver locks the yellow dye developer in place.

[00:26:35]But, look at the layers below. The magenta and cyan dye developers have migrated. What does cyan plus magenta make?

[00:26:43]Blue, the original color of light that struck this region.

[00:26:48]The receiver paper is coated with something that fixes the dye developers in place, just like the silver crystals in the emulsion layers, and making a blue spot on the paper in our case.

[00:26:59]Color dye diffusion is, in summary, taking the colors we don't want, fixing them on the film, and allowing the colors we do want to diffuse across and onto the paper.

[00:27:10]The formulation used by Polaroid took 15 years to develop and first went on sale in 1963.

[00:27:17]Howard Rogers was the main driving force behind the color process, and the company proudly boasted they went through 5,000 different chemical compounds to find dye developers that best resulted in a high-quality RGB image.

[00:27:30]I can't believe all this works, but the end result is this.

[00:27:37]This is the best consumer-available instant film ever made in terms of image quality.

[00:27:42]Let's see how we take a photo with it.

[00:27:45]Using one of these so-called pack film cameras is a little simpler than roll film. To take a photo, we unfold the camera, the mechanism, and focus.

[00:27:55]The shutter button exposes the film, and to develop it, we first pull on this tab.

[00:28:00]This pulls the film and receiver paper together, and exposes a second tab.

[00:28:05]We pull that, and the developer pouch is spread between the film and receiver paper, and the whole assembly pressed together by the rollers.

[00:28:13]Leave for 2 minutes and peel apart to reveal our image.

[00:28:18]Note, this image is significantly higher quality than that of modern integrated Polaroid film.

[00:28:24]Though not designed for this purpose, it's even possible to remove the black backing from the film and scan it to blow it up to a much larger image.

[00:28:32]Now, you'll have noticed I'm basically just showing holiday photos of my family here.

[00:28:37]I've censored my kids' faces they can decide if they want to appear in my videos when they're old enough to make that decision.

[00:28:43]You'd think I'd go out and take some general and less personal photos for a YouTube video.

[00:28:49]The fact is this film is too precious for me to waste even a single shot for video purposes. Let's find out why.

[00:29:02]Most of you will never get to do what I just did.

[00:29:05]Though Polaroid were the original manufacturers of peel-apart film, Fuji produced a better version starting in 1984.

[00:29:14]FP-100C beats Polaroid's formulation by basically every viable metric.

[00:29:20]In 2016, Fuji stopped manufacturing it forever.

[00:29:25]The few remaining packs sell for upwards of $150 on eBay with the price increasing every year.

[00:29:32]Though all are now expired, I can testify that even 20-year-old FP-100C produces excellent images.

[00:29:41]For reasons I do not fully understand, but I assume to be everyday bureaucracy, Fuji never made the formulation public.

[00:29:49]Nobody knows how to make peel-apart color film.

[00:29:53]Yeah, as I've said in previous videos, you can uninvent things.

[00:29:58]I have enough left in my fridge to last a little while longer.

[00:30:02]I fear this video may drive the price up even further.

[00:30:06]It's likely I've already purchased my last ever pack.

[00:30:10]But there is some really good news.

[00:30:13]New peel-apart color film may be out of reach for now, but Fuji also used to make FP-3000B, an equally high-quality and also a very high-speed black and white film.

[00:30:27]When I first thought of making a video on Polaroid more than 3 years ago, I was going to dedicate about half the video to my futile attempt to recreate this film. I'd spent a significant amount of time in my attic reading up the sources for what became this video and trying to formulate my own version of FP3000B.

[00:30:47]I never got there.

[00:30:49]But it turns out I did actually get quite close because in those past 3 years another hero has emerged. While I was away making other videos, a new user appeared out of nowhere on the Fotrio forums, Alec Myers. His first post on the forum was this along with a recipe and instructions on how to make it. Now, his recipe was similar to the final formulation I tried 3 years ago. If I'd swapped silver nitrate for zinc nitrate, it may have worked.

[00:31:22]But that's not important because Alec has put in way, way more work than I did.

[00:31:28]His latest formulation gives results that look like this.

[00:31:33]He's been improving it in the 2 years since.

[00:31:36]And he has a website which is, of course, linked in this video's description with all the necessary instructions.

[00:31:42]So, let's make some up. This latest recipe is basically completely different to his initial one and it has a pretty sizable list of difficult to get hold of chemicals.

[00:31:52]That means one thing. It's time for a shopping trip. And the best type of shopping trip.

[00:31:59]Trying to convince industrial sellers in China to send me small quantities of hazardous chemicals.

[00:32:38]Yeah, it's time to make peel-apart film in my attic.

[00:32:41]But, we do need to get serious for a second. I'm having great fun here, but I am taking proper lab precautions.

[00:32:48]Nitrile gloves, eye protection, water nearby in case I spill something all over myself.

[00:32:54]I'm only using small quantities of each chemical and right under an open window.

[00:32:58]If I was making larger batches, I'd be doing it outdoors.

[00:33:02]In fact, I poured out the chemicals I obtained from China outdoors just in case what I'd been sent wasn't what was advertised.

[00:33:10]So, we'll treat everything here as toxic and corrosive.

[00:33:13]Some of the chemicals most certainly are toxic and corrosive.

[00:33:17]The potassium hydroxide is most certainly the latter. Get that in your eyes and you'll never get to see the results of your work.

[00:33:25]So, I'm not saying don't try this at home. I want people to try this at home.

[00:33:30]But, make sure you know what you're doing first.

[00:33:34]If you aren't confident, Alex's earlier recipe uses more benign chemicals, so you could practice with that one first.

[00:33:41]Also, Alex does have a YouTube channel and some videos of him making an earlier version of the recipe.

[00:33:47]His receiver paper recipe used in that video is similar to the one used in this later iteration.

[00:33:53]I recommend you watch his videos, too, before trying to make anything.

[00:33:57]I'm doing it here as more of a fun demo and independent proof that it works. I just want to keep stressing all the hard work here was done by him, not me.

[00:34:07]Okay, here we go. There are two components we need to make, the mono developer and the coating for the receiver paper.

[00:34:15]The developer is light sensitive and will degrade if left in air and light for more than a few hours. So, we'll make the receiver sheet first.

[00:34:24]The list of everything you'll need is on screen now or Alex's linked webpage. We begin by making up some solutions. Let's start with the most expensive ingredient, palladium two chloride.

[00:34:35]Be careful with this. You're probably just going to purchase it by the gram, and you only need a tiny amount.

[00:34:42]This eventually is going to form the nucleation sites on our paper.

[00:34:46]Take 50 mg of palladium chloride and add it to 50 ml of water.

[00:34:51]Set it in a magnetic stirrer.

[00:34:54]You'll note my cheap drug dealer scale.

[00:34:57]Feel free to laugh at me in the comments for that, but I don't know. It's surprisingly accurate. Certainly fine for our needs today.

[00:35:05]Separately, take 50 mg of potassium chloride and dissolve it in a few drops of water.

[00:35:11]Add the potassium chloride drop by drop until the palladium chloride is dissolved.

[00:35:16]Bottle this solution and label it.

[00:35:19]Take 1 g of sodium sulfide and dissolve in 100 ml of water.

[00:35:24]Bottle it.

[00:35:26]Mix 10 ml of polysorbate 20 with 100 ml of water.

[00:35:31]Bottle it.

[00:35:33]Now, pour 10 g of colloidal silica rigidizer into a beaker and turn on the stirrer.

[00:35:40]It's preferable to vacuum filter it first.

[00:35:43]You can MacGyver a vacuum filter together with a couple of bottles, some tubing, and a syringe.

[00:35:49]To the silica suspension, add 0.5 g of the palladium chloride solution. There is an option in Alex's recipe to add PVP solution here.

[00:35:59]I'm skipping it. It increases the shelf life of the solution, but we're going to make up the paper immediately, so we don't need it today.

[00:36:07]Now, add just two drops of the sodium sulfide solution and leave stirring.

[00:36:11]You'll see the solution turn to a darker color.

[00:36:14]It now contains a suspension of tiny palladium particles.

[00:36:20]Add in two drops of the polysorbate 20 solution and stir again.

[00:36:25]This is our receiver paper solution.

[00:36:27]We're going to apply it to the paper immediately as it's not shelf stable, but the paper is. That can be stored effectively indefinitely.

[00:36:36]For that, we need sheets of waterproof paper.

[00:36:39]I used a generic brand, but Alec recommends this one.

[00:36:43]We need a very flat surface.

[00:36:46]A granite surface plate is the best option to get a good finish. And we need a wire coating bar. I am using a 4-micron bar with a handle I built myself out of scrap because once again, I was too cheap to buy a proper handle.

[00:37:00]Take up 1 ml of the solution in a syringe and apply it in a line across one side of the paper.

[00:37:06]Then use the coating bar to spread it across the page.

[00:37:09]This solution will give us about 10 sheets.

[00:37:13]Leave them to dry and cut them to whatever size your camera takes. It'll probably be 4.25 by 3.25 in.

[00:37:22]Okay, excellent. Now, let's do the developer. Mix 25 g of CMC, full name on screen, with 1 L of water and blend it.

[00:37:32]The aim is to get it completely smooth with no lumps as it's a thickening agent and will form the gel, which is spread over the film. Note, and I forgot to say this earlier, whenever I say water, use distilled water.

[00:37:45]Leave the gel overnight or even better, put it through a vacuum degasser to remove bubbles. Take 25 g of this CMC mix and add 5 g of potassium hydroxide and stir to dissolve.

[00:37:58]Add the powder to the gel to avoid the chance of a violent reaction. Yeah, all right, pause. I'm not doing a great job of setting a good example here, am I? I should be wearing long sleeves, so if I get anything on me, probably won't harm me. Just remember, I'm only using small quantities of chemicals here. I've got water right next to me. Just don't get it in your eyes. And if you do get it on yourself, wash it off straight away, okay? Be careful. Then add 0.9 g of this. I tried to say the name three times. I can't say it. And 2 g of this and stir until dissolved.

[00:38:31]Then add 2 g of uracil and stir for 10 minutes.

[00:38:36]Leave the solution covered in the dark.

[00:38:39]It'll probably be good for a few days at least, but until you can get it into a chemical pouch and finished film pack, it's best to try and stop it from reacting. Okay, that is the chemistry part done. Now to start taking actual photos.

[00:38:53]Initially, I abused a laminator to turn into a pair of motorized rollers.

[00:38:58]The idea was to load a single sheet of film into the camera, take a photo, and press it to the receiver paper with the butchered laminator.

[00:39:05]I haven't mentioned film yet.

[00:39:07]I used Fujifilm HRU X-ray film. I'll explain why in a second. As you'll have guessed from the thumbnail, it actually works.

[00:39:16]I didn't expect it to not work given the amount of replies on the Focrio but still, I'd been dreaming of having a DIY means to produce peel-apart film for 3 years. So, this was a pretty big moment for me.

[00:39:30]Of course, this first photo wasn't great, but it wasn't supposed to be.

[00:39:34]Improving the process was the next step.

[00:39:37]Except this wasn't the first photo I got to work. This was.

[00:39:41]Again, I was still blown away when it actually worked. Now, it's obviously quite faint, so I started working on improving the setup to get a better spread of developer.

[00:39:50]But everything kept coming out really faint.

[00:39:53]It turned out this is cuz I'd tried to be clever.

[00:39:56]Alex says he used X-ray film because it's cheap to buy in bulk.

[00:40:01]However, and here's a niche consequence of having a nationalized health service, the UK pretty much universally stopped using film in X-ray machines 15 years ago.

[00:40:11]You cannot buy the damn stuff here.

[00:40:14]So, I I I'd use consumer orthochromatic film instead.

[00:40:19]Oh, yeah, orthochromatic film. That's film that's not sensitive to red light.

[00:40:24]That was so I could do all this under a safe light. If I wanted to do this with panchromatic film, I'd need night vision goggles.

[00:40:32]Anyway, it turns out consumer film has a protective layer on the top. That was hindering the diffusion process, hence the faded images.

[00:40:41]So, a very kind Patreon member responded to my pleas and purchased and sent me a pack of X-ray film from Poland via express shipping.

[00:40:49]And that worked immediately.

[00:40:52]I then just kind of went around experimenting with different development times and camera settings, largely taking photos of the cats.

[00:40:59]Which are pretty rubbish subjects as they won't sit still in good lighting in front of a white background.

[00:41:04]So, I did a few controlled photos under standard lighting.

[00:41:08]I figured the B-29 model was a good subject given Edwin Land's first commercial invention was polarizing filters for flight crew sunglasses.

[00:41:16]Yep, he invented that, too. Hence the name Polaroid.

[00:41:20]These photos don't look good, but they didn't need to. I just wanted to figure out the best parameters.

[00:41:26]I landed on 0.5 ml of developer fluid, 90 seconds of development time, and a camera ISO of 150.

[00:41:34]That makes this film more like the Fujifilm FP-100B than the FP-3000B I mentioned earlier.

[00:41:41]I then just kind of went back to photographing the cats again, to be honest. More like specifically. She sits still and shows up well in black and white.

[00:41:51]Hang on though, this all defeats the purpose of a Polaroid if I have to keep development in the dark room.

[00:41:58]Yeah, so it turns out peel-apart film was another wonder of manufacturing.

[00:42:03]So, I started working on something that can be done entirely without a dark room.

[00:42:07]I tried making a clone of FP-100C film shots using black paper.

[00:42:13]For the darkroom developed photos, I've been taping together greaseproof paper to make chemical pods.

[00:42:18]I tried a more drug-adjacent paraphernalia approach with little grip lock bags, but they didn't rupture reliably.

[00:42:26]For my attempt at DIY pack film, I'll just use these for now, but I'll figure out a better way to make chemical pods in the future.

[00:42:34]I haven't completely got all this to work yet, unfortunately. I can take a photo, but every time I pull on the tab, it never quite makes it through the rollers. I tried machining a new narrower roller and fitting that, didn't work.

[00:42:48]I tried coating it with silicone tubing, that didn't work. I tried coating that with Teflon tape to help the paper through, that didn't work.

[00:42:57]I can even take a photo, go into the darkroom, pull the film through the rollers, come back outside into the light, and peel it apart, and it works.

[00:43:07]So, my setup blocks the light from getting to the film.

[00:43:10]I just haven't quite got there yet with crafting something that pulls through the rollers consistently.

[00:43:16]So, I'll experiment with some different types of paper in the coming weeks and post a final setup to the project files.

[00:43:22]Each of these shots took an hour to make, only for them to get jammed in the rollers, so I I needed a break.

[00:43:28]Incidentally, all this will be much easier on a roll film camera, where the development takes place in the camera.

[00:43:35]So, guess what I'm on my way to buy now.

[00:43:39]To try and get some actually good photos to show off, I went and shot some big ugly brutalist concrete buildings, because one, I'm doing a video about them next year, and two, they're already black and white, so I'm less likely to screw up actually photographing them.

[00:43:55]And the results? Well, honestly, I'm pleased with what I have so far.

[00:43:59]I'm showing the best photos I've managed today on screen.

[00:44:02]Folks on the Photrio thread, most notably Analog Wisdom, have achieved better results.

[00:44:08]Oh, and the recipes I presented are just one of many discussed there. They continue evolving.

[00:44:14]My shots have more of a sepia tone than I'd like, I need to figure out how to make the white areas actually white. And I definitely need to get a surface plate to get a better finish.

[00:44:24]But these look really good so far. So, I'll continue improving the process and take this out to get some better results in the coming months. I'll post anything interesting with the rest of the project files.

[00:44:36]So, a huge thank you to Alec Myers and everyone else involved on Faux Triode for essentially ensuring there's an open-source means to keep peel-apart instant photography alive forever.

[00:44:48]And if that wasn't good enough, while I was writing this script, Light Lens Lab, a small Chinese film company, gave us an update on their attempts to automate this process.

[00:44:59]You may never need to do everything I did here because you may soon be able to buy commercial peel-apart film again.

[00:45:06]But with the process Alec devised and I've demonstrated in this chapter, the world will never be reliant on a single company staying afloat to keep this amazing format alive.

[00:45:16]I will say One Instant have also been making limited batches of peel-apart film recently, too, but they've been using old chemical and paper stock.

[00:45:24]This has served as an excellent stopgap until Light Lens Lab can get their from-scratch formulation into production. Now, I just want someone to figure out how to do it in color. My god, that would be fantastically difficult, but just imagine.

[00:45:40]On second thoughts, a couple of days before I was going to release this, a patron, who, by the way, has been pivotal to this video as he also recommended several sources to me, asked this.

[00:45:54]I wonder if you could auto-chrome a peel-apart.

[00:45:59]What a bombshell.

[00:46:00]I never thought of that.

[00:46:03]I wonder there may actually be a route to DIY instant color film that doesn't involve impossibly complex chemistry after all.

[00:46:12]No promises, but I'm going to work on this.

[00:46:15]I wanted to make it public because whatever I do, someone else watching will be able to do it better.

[00:46:21]If I manage to do what I think is possible, I'll do a video on it.

[00:46:31]The final step. How do we do everything we've done so far, but with the press of a button?

[00:46:37]How do we make an image materialize in broad daylight?

[00:46:42]If you've made it this far into the video, first of all, congratulations.

[00:46:46]You've put in the work to properly understand the process instead of just watching a 2-minute overview.

[00:46:51]Secondly, we've done the hard part.

[00:46:55]Polaroid integral film operates using the same process as peel-apart color film, just with some minor changes.

[00:47:02]First of all, this is film intended for use by everyone.

[00:47:06]As much as I love peel-apart film, it is a fact to manhandle the camera and deal with caustic chemicals in public, and it depends on the user actually doing things correctly. So, let's seal the entire process in a plastic envelope with a clear window on the front.

[00:47:22]Add in our halide and dye coupler layers along with the light filters from earlier.

[00:47:27]The chemical pod goes here and will be ruptured and spread across the film with a pair of rollers.

[00:47:33]Now, let's replace the receiver paper with something transparent. If we can get the dye developers to migrate across this and undergo the color fixing reaction, we'll have an image visible through the clear window.

[00:47:45]That isn't going to work, is it? As soon as the film is ejected, it'll be exposed to light, which would destroy the latent image and soon-to-be developed image.

[00:47:55]We need to somehow make the reagent opaque.

[00:47:59]But it also needs to be completely white at the end of the process to give a white background. Okay, first add titanium dioxide to the reagent pod.

[00:48:09]This is what sun cream is made of. It's highly reflective and gives a brilliant white background.

[00:48:15]As the film passes through the rollers, this is applied across the top of it and stops some of the light getting through and exposing it as it develops.

[00:48:23]This thin layer of titanium dioxide is not sufficient to block all the light though. So opacifying dyes are also added to protect the film fully.

[00:48:32]The development and dye migration progresses exactly as with peel-apart film, but shielded from the light by the opacifying dye.

[00:48:40]Earlier, I showed this to explain how additive mixing through filters is used in the film negative.

[00:48:46]Now consider the migrating dyes which will form our positive. How do we make black? Mixing dyes on a white background is a subtractive process. So unlike light through filters, areas with all three dye couplers present mix to give black areas.

[00:49:03]Anyway, that is all great, but we have two issues to resolve. How do we see the final image given it's against a dark opacifying dye?

[00:49:12]And how do we stop all the chemical reactions?

[00:49:15]Both of these are solved with an acid polymer layer.

[00:49:18]Back at the start of this video when I demonstrated photo development in a darkroom, I omitted the use of a stop bath after the development stage.

[00:49:27]But submerging a developing image in acid will stop the reaction entirely.

[00:49:32]The acid polymer layer releases acid on contact with moisture. A timing layer below it is calibrated to slow down migration of the developer solution upwards to activate the layer and then to delay the released acid reaching the layer below.

[00:49:46]When image formation is complete, the acid reaches the reagent layer and stops the development and fixing process by neutralizing the overall pH of the solution.

[00:49:57]It also reacts with the opacifying dyes to turn them transparent, leaving our final image on a white background.

[00:50:04]The penalty for all these extra layers and complexity is a lower image quality.

[00:50:10]It's just a trade-off of obtaining a one-touch process.

[00:50:14]Oh, by the way, Polaroid images develop better if you don't leave them out developing in the sun.

[00:50:20]You can get a little attachment for the camera that shields them. So, while I leave them out to show the process in this video, don't do that if you want the best image. But, do take a second to admire the sheer effort that must have gone into finding chemical compounds that all interacted correctly with each other in this big soup to give perfect red, green, and blue dyes at the end.

[00:50:43]As with FP-100C, Fuji went on to refine the process somewhat.

[00:50:49]Their Instax film gives higher quality images than Polaroids, though I am comparing the modern-day formulation from Polaroid here. It may improve in the future.

[00:50:59]Thing is, Polaroid made the better cameras.

[00:51:04]The film is, I'd say, one of the four features of this camera that, to the uninitiated, are indistinguishable from magic.

[00:51:13]Or certainly would have been in 1972 when this first sold.

[00:51:18]I've not had the time to go into details of the earlier Polaroid cameras in this video, but the SX-70 is something else.

[00:51:26]The second thoroughly impressive feature is the fact that it is an SLR, a single-lens reflex camera.

[00:51:33]Okay, so as some viewers may have gathered, I'm not actually into photography as such. I really like cameras and the film development process, but I don't really take many photos in my everyday life.

[00:51:48]For those unaware, an SLR like the Olympus I showed off earlier is basically the gold standard for a proper camera.

[00:51:55]The crucial characteristic is that the view through the viewfinder is created through the lens. It doesn't have a separate viewfinder.

[00:52:02]So, what you see is what the film sees.

[00:52:05]I am drawn to SLRs because they are mechanically beautiful. Now, ask yourself, how does this give a common light path to both the film and the viewfinder?

[00:52:16]Polaroid commissioned a fantastic informational film explaining all of this.

[00:52:22]Honestly, I'd just use the graphics exclusively from that if they hadn't already been used in practically every SX-70 video already.

[00:52:30]So, I'll do some of my own animations, too. But, honestly, the original live-action footage is better than my rendering, so I've linked it here.

[00:52:39]Oh, and I've referenced this before, but someone built a working camera in Blender, and it's one of the most impressive things I've ever seen.

[00:52:46]I am not going to build a working SX-70 here, I'm afraid. We'll just have to live with my renderings being merely okay.

[00:52:54]Okay, lens and shutter. The shutter is a sliding leaf. I don't have time to go into the details, but it's driven by a solenoid, and I think it may be a unique design.

[00:53:04]Now, we need to get light through this lens to the viewfinder.

[00:53:08]In other words, the shutter has to stay open when we aren't taking a photo, yet somehow do so without exposing the film.

[00:53:17]Let's start with a mirror on the back wall.

[00:53:20]By itself, that would actually give us a working camera already, as the light would be reflected onto the film to form an image when the shutter opens.

[00:53:28]In fact, that camera was eventually built, the lower-cost SX-70 Type 3.

[00:53:35]But, we're striving for perfection here.

[00:53:36]We need an SLR.

[00:53:38]So, cover the film with a plane.

[00:53:41]This stops any light getting to it while we aren't taking a photo.

[00:53:46]But it also stops light getting to the viewfinder.

[00:53:49]So, on the back of that plane, add a Fresnel reflector.

[00:53:53]This kind of acts as a focusing mirror.

[00:53:56]It would focus the light to a point here, but it hits the first mirror again and passes out of the camera body through two slits here.

[00:54:05]Finally, it's focused to an image by a curved mirror here and the viewfinder lens.

[00:54:11]Of course, I'm underselling all of this vastly. The geometry of the optics was completely unprecedented for the time.

[00:54:20]These were freeform optics. The mirror for the viewfinder alone was described by an eighth-order polynomial of rotation.

[00:54:27]The tooling to manufacture these optics was absolutely out of this world for the 1970s.

[00:54:33]Air spindle bearings, CNC machining on granite beds, and nanometer scale precision.

[00:54:40]I could probably do an entire video on just that, but we'll have to make do with some of the sources in the description for now.

[00:54:47]Okay, let's take a photo.

[00:54:49]We'll do the full sequence in a second, but internally, the shutter's closed and our Fresnel reflector flips upwards.

[00:54:56]There's a second mirror on the underside of that plane, which reflects incoming light to the film.

[00:55:03]So, now the shutter opens and exposes the film.

[00:55:06]Done.

[00:55:08]The SX-70 absolutely did not need to be an SLR.

[00:55:12]I think it took a certain type of person and company leadership to press for it to be so.

[00:55:18]Land was not shooting for merely okay here.

[00:55:22]I've probably been approached by more strangers over this camera than anything else in my life.

[00:55:28]And that's because of this, the second magic feature.

[00:55:34]There is honestly very little I have to say about this because the action itself speaks louder than any explanation I can give. Note how the camera itself isn't actually much bigger than the film cartridge.

[00:55:46]The motor and drivetrain are here.

[00:55:48]The mirrors are here. And the lens and shutter and electronics are here.

[00:55:53]The bulk of the physical design was done by a team under James M. Connor working for Henry Dreyfuss Associates.

[00:56:00]Henry Dreyfuss being arguably the best industrial designer in history.

[00:56:04]At the start of the video, I vaguely compared the camera to an iPhone. I mean, yeah. Just look at it.

[00:56:11]I carry this in my jacket pocket regularly.

[00:56:14]Land famously first presented it to shareholders by stepping on a stage, pulling one out of his pocket, and taking 10 photos in rapid succession.

[00:56:22]Handing the photos out to audience members who watched them develop in real time.

[00:56:27]Does that sound familiar?

[00:56:30]Steve Jobs later stated that Edwin Land was one of his main inspirations and he modeled much of his presentation style and ethos around him.

[00:56:38]The SX-70 is a classic example of sacrificing some capability, in this case image quality, to make a product that is universally appealing to the everyday consumer.

[00:56:50]Just like an iPhone. Or an Apple Macintosh.

[00:56:54]I'm not saying it's a bad thing, but the parallels between Polaroid and Apple are blindingly obvious once it's pointed out.

[00:57:01]All that said, and on a personal note, Land strikes me as more amicable than Jobs ever was.

[00:57:07]Most of the stuff Jobs was notorious for is corporate drama that I don't care about. I never liked the guy because he was a deadbeat dad who abandoned his daughter.

[00:57:16]But anyway, we can come back to that later.

[00:57:20]The final seemingly magic feature was Land's original vision.

[00:57:24]It was one press and fully automated.

[00:57:28]This was controlled by three integrated circuits on the main board.

[00:57:32]This in itself was highly ambitious for a consumer product in 1972.

[00:57:37]A competition for the board saw Fairchild as the initial winner of the contract, but after 1973, a Texas Instruments board was used which cost only around $4 to manufacture.

[00:57:48]I'll not go through the full photo sequence in full detail as that original Polaroid video does that. But in summary, pressing the shutter button energizes the integrated circuits and causes the shutter to be closed.

[00:58:01]The shutter blades close a contact for the driver motor.

[00:58:05]The motor itself is much more impressive than it looks.

[00:58:09]It's pretty compact but can draw about 2 amps at 6 volts, which is that is an awful lot.

[00:58:16]Oh, speaking of which, where's the battery?

[00:58:19]It's in the film pack.

[00:58:21]The super flat zinc chloride battery was another major innovation.

[00:58:25]And unlike a lithium-ion battery, it can deliver much more current. Hell, when you'd shot all the film in a pack, you were left with a still partially charged battery.

[00:58:35]Polaroid later used to give out these as part of a promotional campaign.

[00:58:39]Put your used cartridge in and the battery powers a radio.

[00:58:43]I bought this just for this video.

[00:58:45]I guess it'll live on my shelf of cool things now.

[00:58:50]Anyway, the photo sequence.

[00:58:52]The motor turns a few revolutions to release a cam which releases the spring-loaded Fresnel assembly flipping it upwards.

[00:58:59]This also opens a contact and stops the motor.

[00:59:03]The shutter, as you may have gathered, requires power to stay shut, not open.

[00:59:08]The contact that the motor opened also cut power to the shutter, so now it opens along with a second shutter on the light sensor. Light falling on the sensor induces a voltage which begins charging a capacitor.

[00:59:21]When that is charged to a sufficient voltage, it triggers the shutter solenoid valve which closes the shutter again. A signal is also sent to the motor driver IC.

[00:59:31]The motor starts up again at this point and drives the gear train which drives a little arm forward to extract the film through the rollers which are also driven by the gear train and pull the film through spreading the chemicals.

[00:59:44]The drive train also lowers the mirror and just to show off a little more advances the film counter.

[00:59:52]All that done without CAD and without 3D modeling.

[00:59:56]There were later cheaper versions of the SX-70 which weren't as good. I've already mentioned the type three.

[01:00:02]Subsequent more expensive revisions added sonar focusing and an inbuilt flash to give the Polaroid 680.

[01:00:10]Many state that this is the best instant camera ever made.

[01:00:13]I personally disagree.

[01:00:16]Focusing a camera really isn't that hard and I can use a flash with this if I want to.

[01:00:22]I don't really want the giant chungus module ruining the form and stopping this from fitting in my jacket pocket.

[01:00:29]The SX-70 might not be the best instant camera in terms of image quality but it's the best in terms of everything else.

[01:00:42]Let's have a look at my SX-70.

[01:00:44]This would have been the basis of my original video back in 2023.

[01:00:49]It's a shame I never saved the images from the original listing because this was pretty beat up when I bought it.

[01:00:54]Someone had dropped it, it didn't even close properly but it did cost me just $43 plus postage so I was hardly taking a huge risk here.

[01:01:03]I spent a couple of days figuring out how to disassemble it using the servicing manual and a video that I've linked in the description.

[01:01:10]There are a couple of things to be aware of when taking one of these apart.

[01:01:14]First, the screws to remove the lower cover are all under the leather.

[01:01:18]There's no way of removing it in one piece. It's held on with some ridiculously strong adhesive, which is probably considered a toxic hazard or something today.

[01:01:26]But if you're careful, like I was, you can peel the top layer off the leather and glue it to a piece of card to stick back on later.

[01:01:35]Second, all the screws have a square head for some reason. So, you'll need to make a tool. I just filed down a small hex key. Now, when I'd bent the folding mechanism back into place, I inserted a test film and nothing happened.

[01:01:49]A little Googling and the main suggestion was to clean the contacts here.

[01:01:53]These are the main power switch. They mate when the camera's opened, and they can corrode over time. So, I cleaned them with some sandpaper and hooray, a working SX-70 for $43 and about 3 days of time.

[01:02:06]I left the chip out the case where it had been dropped. It adds history, I guess.

[01:02:12]By the way, you can see here how the case is actually just plastic coated with metal.

[01:02:16]The SX-70 is amazing, but it still doesn't have the build quality of something like my Olympus OM-1 from earlier.

[01:02:22]Though that latter one did cost double that of an SX-70 back in the day. I also didn't replace the leather panels with new unscuffed ones.

[01:02:31]This thing's for carrying around to interesting parts of the world. I don't want it to look perfect and pristine.

[01:02:37]I shot a couple of film packs with it in this state with the intention of making some modifications in the coming months.

[01:02:44]However, the most important modification was forced upon me.

[01:02:48]On a night out, I pressed the shutter button and clunk. Whirr.

[01:02:54]And the whirring only stopped when I closed the camera and broke the contacts.

[01:02:59]Let's see what happened.

[01:03:02]The drive motor for the camera is connected to the gear train via a spring.

[01:03:08]I presume this is due to the high power of the motor, so the spring gives a dampening effect and stops the assembly from tearing itself apart.

[01:03:16]To connect the motor shaft to the spring, Polaroid used the cheapest, flimsiest little bit of transparent plastic imaginable.

[01:03:25]If you have an SX-70, this will shatter at some point.

[01:03:30]I was going to preemptively replace mine, but the camera got there first.

[01:03:35]And yeah, it's easy to say you'll preemptively do it.

[01:03:38]But if you have an awesome camera that's working, it takes a certain discipline to disassemble it just to make sure it continues working.

[01:03:47]Anyway, I have a really nice little model making lathe, and I restored that as well a couple of years ago, but that's another story. So, I set about making a new coupler.

[01:03:57]Initially, I tried brass, but the central surface had to be just half a millimeter thick, and brass just keeps falling apart.

[01:04:04]So, I made one out of steel instead.

[01:04:07]Here's the schematic. I'll include it in the files.

[01:04:09]And here it is fitted to the camera just before I put the cover back on.

[01:04:13]Very nice. That will last forever.

[01:04:16]Okay, my next upgrade wasn't to correct a design flaw, rather just an update to keep the camera usable.

[01:04:23]SX-70 film is quite slow. It has an ISO of 100, so it's only suitable for use in good lighting, almost always outdoors.

[01:04:32]That wouldn't be a problem by itself, just use the camera in appropriate lighting.

[01:04:36]But the vast majority of film manufactured by Polaroid today is for the newer models of camera.

[01:04:42]Those use 600 ISO film.

[01:04:45]Run that through a stock SX-70, and it'll be overexposed.

[01:04:50]Now, there are a few methods available to convert an SX-70 to use 600 film.

[01:04:55]None of them are adequate for me. I want this to be still capable of shooting the original slower film, which Polaroid do still manufacture in occasional batches.

[01:05:05]So, I added this toggle switch, which allows me to switch between the two settings.

[01:05:10]This required removing the front cover, and then removing a capacitor from the main circuit board.

[01:05:15]This capacitor here. It controls the shutter speed.

[01:05:19]In a stock SX-70, it has a capacitance of around 1 nanofarad.

[01:05:24]If we were to replace it with a 150 picofarad capacitor, the shutter speed would be appropriate for 600 ISO film.

[01:05:32]However, I designed this little PCB which includes both options and a toggle switch to change the setting.

[01:05:39]Incredibly, the one and only area of unused volume in this camera is right here. It's about 1 cubic centimeter right under the cover.

[01:05:49]So, I soldered the two outputs of my PCB to the pads the capacitor used to occupy and crammed the little PCB into that void.

[01:05:57]A hole drilled in the casing here allows the toggle switch to pass through.

[01:06:02]An elegant solution that ensures my camera can use both kinds of available film. Next up, a flash.

[01:06:09]Okay, so originally, the SX-70 was designed to use these flash bulbs.

[01:06:14]Polaroid sold them in bars of 10 to stick on top of the camera.

[01:06:18]Flash bulbs are really bright. So, when this port is occupied, the camera closes the aperture far more than normal to compensate.

[01:06:26]But, Polaroid were kind of showing off here. When a flash is inserted, the normal light meter is disabled.

[01:06:33]The focus knob includes a spiral groove.

[01:06:37]That connects to this rocker arm via a pin. The further out the focus, the more this rocker arm moves across and moves a little detent which opens the shutter if the focus is further away to let more light in from the flash.

[01:06:52]Very clever. But, I wanted to use an electronic flash.

[01:06:56]I bought an old third-party one and put it in a more compact 3D printed case.

[01:07:01]Replacing the batteries with a single rechargeable lithium battery allowed me to fit everything into the smaller case.

[01:07:07]The issue now, the images would be too dark.

[01:07:11]Electronic flashes aren't as bright as flash bulbs.

[01:07:14]The common modification is to remove the rocker arm, so the aperture just stays fully open when a flash is inserted.

[01:07:21]But, as you probably gathered, I like to have the option to use the original functionality if possible. So, I made a new arm.

[01:07:29]This one connects to the brightness controls.

[01:07:32]Oh, yeah. The original arm had two inputs. One was the focus wheel, the brightness control.

[01:07:39]We don't need to worry about the focus wheel here.

[01:07:41]This one allows me to manually open or close the aperture by turning the brightness knob.

[01:07:47]This setting is only applied when a flash is inserted. If not, the light meter is still used for full aperture control, and the normal brightness adjustments remain functional.

[01:07:58]In other words, my electronic flash, I just set the brightness to high and get full aperture. If I use flash bulbs, I can manually close it if the target is close in.

[01:08:08]My arm here was just made using a pair of tin snips, by the way. I said I'd machine a better looking one, but well, it's been 3 years and it still works fine.

[01:08:17]I still have the original, just in case I wanted to revert it. And finally, accessories.

[01:08:22]You can't have a Polaroid without a self-timer.

[01:08:25]An alternative to pressing the shutter button is to close these two contacts here.

[01:08:30]Polaroid used to sell a little mechanical timer that did just that. And you can get after-market ones, too.

[01:08:36]Or you can go for my option and build one for just a few dollars.

[01:08:40]Here is a PCB with a little battery and a reed switch, which closes the contacts.

[01:08:45]A triple five timer gives a delay of about 7 seconds between throwing this switch and the camera taking a photo.

[01:08:52]As always, PCB design and instructions in the files.

[01:08:56]Partly due to the amount of work I've put into this, and partly because of its beautiful design, this camera has become one of my most prized possessions over the past few years.

[01:09:06]I'm confident I have the skillset and tools to replace any part of it that could conceivably fail in the future.

[01:09:13]Even if it becomes a camera of Theseus, I intend to keep it working for the rest of my life.

[01:09:23]The SX-70 most certainly had its teething problems at launch, but it went on to be a success both commercially and technically.

[01:09:32]At the end of the 1970s, Land made a hell of a blunder with Polavision, which was instant movie film.

[01:09:39]It was another astonishing technical achievement, but it was a terrible consumer product.

[01:09:45]It's often misattributed as the product which finished off Polaroid, but that's nonsense.

[01:09:51]It was the product that finished off Land as Polaroid's frontman.

[01:09:55]Who remembers the days when a bad decision would have actual repercussions for a company and its senior management?

[01:10:01]That, well, doesn't seem to happen much anymore, does it?

[01:10:06]Nobody remembers or retrospectively denigrates Land for this one blunder, though. He's remembered and celebrated for his 535 patents and his unbelievable technical and scientific legacy.

[01:10:18]But the company had another 20 years of success through the integrated film originally designed for the SX-70 with a faster 600 ISO version launched a few years later.

[01:10:29]Polaroid spent the '80s far cheaper and more accessible cameras.

[01:10:34]Yes, they aren't a marvel of engineering like the SX-70, but they're also the reason that most people that have shot Polaroid film have had the chance to do so at all.

[01:10:42]And that takes us to the turn of the millennium.

[01:10:45]And I'm going to skip forward to a very specific date, which should have been the most important day of my life in itself, but it somehow ended up being even more important than that.

[01:10:57]I got married on the 5th of September, 2015.

[01:11:01]When I said this video was 3 years in the making, the sequence of personal events which led to it actually began on my wedding day more than a decade ago.

[01:11:11]I've mentioned in earlier videos about how building some trinkets for the wedding eventually led to me making YouTube videos.

[01:11:18]But I haven't mentioned the Polaroid camera our wedding photographer brought along with her.

[01:11:23]We didn't want boring rehearsed group photos, so we hired a more interesting and arty photographer.

[01:11:29]At the end of the day, she handed me these.

[01:11:32]Not only was I amazed by the quality, having grown up with Polaroid cameras being considered as more of a toy by then, but well, I thought they'd gone extinct.

[01:11:42]On the back, the Impossible Project.

[01:11:46]And oh boy, did that send me down a journey.

[01:11:51]You need to go and watch the documentary An Impossible Project or any of the other documentaries on YouTube about this man, Florian dot caps.

[01:12:01]Because I do not have the time to go through it all today. Dr. Florian goes front and center in the list of heroes we've discussed today.

[01:12:10]This is the man who saved Polaroid.

[01:12:13]The company went bankrupt in 2001 and announced they'd close the last factory in 2008. After a frankly comical amount of persuasion, hard work, and just good old-fashioned hustling the right people, Florian eventually ended up buying the factory, reformulating the recipe, and keeping production going. He saved integrated Polaroid film from extinction.

[01:12:38]And remember Supersense I briefly mentioned earlier? He's the guy behind that, too.

[01:12:43]In previous videos, I've mentioned my disdain for people who encourage others to give up at the first hurdle.

[01:12:50]Florian most certainly did not give up.

[01:12:53]As I said, I can't tell the full story today, but you need to go and watch a video and just listen to him talk. He gets it. Why am I really into Polaroid and film cameras in general?

[01:13:07]Why do I have a record player?

[01:13:10]Make physical models for videos.

[01:13:13]Go and visit places to put my hands on things that I talk about in videos when I could just find an image on Google.

[01:13:20]Why did I insist on playing Elite from a tape when I could just use a modern SD card adapter? Why do I get disproportionately angry when people say sending humans to the bottom of the ocean is pointless because AI can do it instead?

[01:13:34]Why do I have this in my house?

[01:13:37]It's not nostalgia.

[01:13:39]Picking up something and holding it or being there is so fundamentally different to just seeing it and hearing it through a screen. I don't think that should come as a surprise to anyone.

[01:13:50]But, you are watching this through a screen.

[01:13:54]If you haven't before, go and get hold of a cheap instant camera and a pack of film.

[01:14:00]Have a go because it's just different.

[01:14:08]The story of Polaroid is one of my all-time great engineering stories.

[01:14:12]Not just because of the man behind it, but also because of the products themselves.

[01:14:17]A product decades ahead of its time, another unmatched decades later, and one which may be the best piece of ergonomic design I've ever held in my hand.

[01:14:28]And you can go and hold it in your hand, too, because all of this is easily accessible to the general public.

[01:14:34]Edwin Land brought color into the world.

[01:14:38]I mentioned the lineage from Land to Steve Jobs earlier, and I will always be resentful of Jobs because he was a primary driving force for removing color from the world.

[01:14:49]White, black, gray.

[01:14:51]I hate white, black, and gray.

[01:14:55]Color started fading from Apple when they sold their last iMac G3.

[01:14:59]And Jobs' new-found obsession at the time with monochrome bled far and wide into the world.

[01:15:06]Cars, consumer electronics, soulless corporate logos, home interiors.

[01:15:12]I have a 7-year-old son who likes colorful things.

[01:15:15]All humans with eyesight like colorful things.

[01:15:19]Buying non-monochromatic clothes for him gets more and more difficult every year.

[01:15:25]Presumably because some fashion designers somewhere once decided boys don't do color.

[01:15:31]The world looks white.

[01:15:33]So, take up your brush and paint the world.

[01:15:37]Wait, no, no. Oh my god, not like that.