Hope you enjoy the video! This one's coming in a bit late for the 2^14 milestone because I just finished my PhD and moved across the country (a task that's still in progress) so bear with me - the channel may be relatively empty for a bit longer while I get settled… I swear there are multiple pre-filmed vids in the pipeline that just need editing! Video corrections: None yet! Find my mistakes! =D

There's a hidden advantage to this setup: Because it takes a picture in ultraviolet, which has a lower wavelength than visible light, it has a higher theoretical maximum resolution for a given lens size. Clearly ultraviolet cameras the the future for smartphone manufacturers on the hunt for more megapixels without increasing the size of their optics.

The cyanotype process is self-inhibiting - the forming dye blocks off UV from hitting the light sensitive iron 3 oxalate. I ran into this issue myself. You will achieve a massive sensitivity increase by just coating the paper with the photosensitive iron 3 salt of choice (I use a mix of Fe3Cl and oxalic acid) and developing the latent-ish (visible as a discoloration of the yellow sensitiser) image in a ferricyanide (or ferrocyanide for a positive image) bath. I got an overexposed image with an f4.5 tessar (4 element, the less glass in the lens the better the uv transmissivity) with just 4h of june sun exposure.

The fact that you're still only at 18k subs is insane. You stated that you don't want to make a patreon because of your random schedule, but honstly, I'd still support it. You could just make it a support per video. I support several channels that only release 1 or 2 videos a year

A person might have guessed that the cyan from cyanotype came from the word cyanide, but it just comes from the greek color word cyanos, for dark blue, which is where the word cyanide also gets its name.

Amazing, I would turn your both photos into negatives to see the photo as it should be seen, it will give you a positive image of your house but with yellow colors

Spherical abberation is actually an well known issue (with an stupitidly simple solution) that commonly got solved by astrophotographers in the 70's and 80's: Just curve the film. Back in those days astrophotographers used so called "Schmidt-Cameras" to capture images of Deep-Sky-Objects, such as galaxies and star clusters. These cameras where build sort of like an Newtonian without an secondary mirror but an place to attach films and where widespread. Schmidt-cameras suffer from the same issue due to its curved focal plane. To curve and cut the films into round shapes they stamped them out using special stampers, that could deform and cut simultaniously. The real question for your camera is, whether you have to curve in or out and at whitch radius. An other option would be an Field-Flattener lens. BUT they get used for corrections on the scale of an fullframe sensor, not at the scale of an whole paper. So a bit too pricy and complex, considering you would have to custom-make that lens. Fun fact: Today curved sensors are relevant and there are rumors Sony works on curved sensors for a better image-quality without expensive optics. The Kepler space telescope is actually an modern Schmid-Camera with an array of curved sensors. Hope this will help or at least inspire you.

_"...and also a wee bit of a tendency to light itself on fire."_ I just *HATE IT* when my camera does that...😊

Those prints are so satisfying, the blue is such a lovely color! To get more light I think you only have one option: rebuild Herschel's 7ft newtonian telescope as a camera 😇 Can't get a better light bucket than a big newtonian! :)

You have to build a R E A L L Y B I G and bright camera flash.

So, since these were essentially negatives, and I have sometimes in the past found it difficult to 'evaluate' or 'analyze' what's in a photo from its negative, I wanted to see what inverted images would look like. Thought somebody else might find this interesting, so here's a link to imgur gallery with the photos processed (simply inverted, or inverted and desaturated to mimic black and white photography): imgur.com/a/v2c4SXv . I have to say, I really like the photo from the front of the house, especially with the blue/yellow color scheme.

The head lab tech at my old schools photography department would take multi month exposures with long since expired photo print paper. She'd abandon pinhole cameras hidden around the city. It was pretty cool seeing the sun tracks shift as the months past on a single photo.

Just learning how blueprints are made blew my mind, the way you made it into a camera is insane! This is very cool!!

I can actually say something because this is my wheelhouse, and I research this for a living as a photograph conservator! I would have a couple of suggestions on this. 1) In regards to aberrations, a simple way to get rid of them is to make a symmetric doublet, and for the focal length you are at, the easiest way to do it would be to get two +1 diopter reading glass blanks, which would add up to 500mm together, and then you could add a lens to bring it up to the 350 mm range using the lens makers formula. If you get your positive meniscii from surplus shed, you can get it pretty cheap, and just use PVC pipe to mount. Also will let you pick your aperture, because some of those meniscii get massive. 2) sensitivity: a good rule of thumb with these things is that water helps with speed. You are on the right track with Ware’s formula ( as a crystallography thing, his cyanomicon is a great read because of how Prussian blue works, and is free online). Arpan Mukherjee’s work using different iron salts is also good, and can be found on alternative photography .com. A final hint would be to sensitize, and dry your paper, but then humidify it using a wet blotter behind it. Wet paper gains around a spot of speed. 3) if you really want to make a project, explore science, and cry, try Lippmann plates. Gabriel Lippmann got a Nobel prize for his work, and a paper which came out just a month ago showed that the Lippmann plate is actually a multispectral resolving surface, so you can actually use the images as a tough imaging spectrometer (good luck, it will never happen because it is so finicky, but in theory, it does work)

Two ideas: reduce spherical aberration by adding a "mold" behind the paper that brings it into focus everywhere (or at least along the longer side to avoid crinkles). Also you could try to use vacuum (maybe a battery powered aquarium pump?) to press the paper down. Great content as always, keep it up!

I have found that most things science that is fun is directly proportional to its potential to bursting into flames. so this camera is thereby a more fun camera to use scientifically speaking.

8:35: Never thought I would see transistor man ever again, but here we are!

When I was a young lad working in a hospital, I had access to xray film stock, which is around 8 x 10 inches. So, I built am 8 x 10 camera with a magnifying-glass lens... When I exposed the xray film and developed it, it came out quiet well... It's perfect for contact printing...

Dollar Tree Poster Board is the material of pioneers! :D

If you didn’t know, there are special transparencies made for printing onto with an inkjet. There are some with a dry gel like layer that absorbs ink well (but washes off with water), and there are also waterproof ones that I think are just made to be particularly porous. Less smudging than using a normal transparency. To get a particularly opaque printing, it’s often necessary to print extra ink (CMY and black all at once), which of course means smudge mitigation is even more important. Big Clive’s videos introduced these transparencies to me for the purpose of making circuit boards with dry film photoresist, which is a rather similar process to your masking of cyanotype paper. Of course, a laser printer doesn’t have those issues at all.

you could make a kind of studio with uv lights and photograph objects for a day or two

I truly enjoy your videos! I used to be an exchange student in physics at UCSB 2013-2014 and these videos bring me a great sense of nostalgia on top of the wounderful content. I currently work as a postdoc focusing on spectroscopy of antihydrogen at CERN, let me know if you ever have your way past one day:) As for myself, I dream that the next conference I attend is at UCSB!

What is the material of the lens? Maybe quartz lens could improve the camera, if it is not already.

I’ve made similar cyanocameras by using USPS Medium Flat rate boxes, paired with a plastic fresnel-lens magnifying sheet in front, and a sheet of cyanotype paper inside the box. With the large fresnel collector lens in front, exposures happen in about an hour and the density of image can be similar to the results seen here. Sharpness from a Flat-Rate Cyanocamera is dependent on the quality of the fresnel; I’d say it’s comparable to a soft-focus Petzvall. Keep the fresnel lens in the shade: this will prevent the sun’s image from focusing back of the box and lighting the whole thing on fire. :)

These subscriber doubling benchmarks seem to be happening faster and faster (even though the numbers separating them are getting bigger and bigger!). Keep it up!

Have you thought about deliberately curving the paper? Like instead of a flat plane you used a concave cylinder. You might get some interesting fish-eye effects with a low focal length. Also maybe do some solarigraphy.

Your curiosity is incredibly inspiring. Love the content, keep it up!

You can actually sell this. People who shoot UFO pics will buy.

I'm not ditching my DSLRs! I started my photo education in 1947 with a Brownie Flash 620; it took me 40 years to get to the stage you got to in however many minutes it took you to prepare to do this video. Now I have all these obsolete film cameras that are too nice to throw out, but they ARE just paper-weights now.

There are these lenses called f-theta lenses, that are used often in laser scanning applications. As the name suggests they have a flat focal plane, so you won't have any spherical aberrations. They do get expensive fast, but maybe you can look into how you can stack some simple lenses to achieve a similar result!

Dude, im all inn. You make great content. Love what your doing. Im very glad i found you so early and get to follow you from the start! ❤

I'm so glad I found this channel. I love your energy, man.

40 years ago we did this with 8x10 (inch) film negatives and the lens from a copy camera that would make 20x24 inch negatives. Then, since we worked in photo labs would print from the exposed film and make 40x60 inch prints. We also used super glossy positive paper to get a slick magazine quality instant picture, albeit backwards. We'd go out for lunch with the cameras and process them in the machines and have prints in less than an hour. The rod technique you used was designed to make "rubdowns" of type or images that could be transferred to paper for layout by rubbing the back of the velum original. The rods had thousands of circular grooves that would evenly spread the photo solution on the velum. After 4 or 5 passes of different pigments and photo sensitive chemicals, the velum was exposed and processed.

Your comment about the photographic paper bowing outwards and subsequent solution made me realize why old time cameras used photographic plates with the paper sandwiched between.

I love home made cameras! I made one of these with a box and a magnifying glass. I didn't use a sensor, I just loved looking at the image it created with my eyes. It feels so unreal to see a lens completely transfer a view onto a sheet of paper.

man, this video put together so many pieces that have always been lost in my head about how cameras capture images!

Sometimes we fixate on details we think are core to a project. Have you considered _different_ photo media? For example you can still buy enlarging paper in silver halide, various color papers and even cyanotype. All of these could be used directly in your camera and produce really awesome looking negative prints. In the case of the cyanotype paper, you could also use some to see if it performs better than your own. You also might be able to do your own silver halide process. It won't be the cool blue and white, but it might expose faster.

Love your enthusiasm!

I had one thought, if no one else has mentioned it. Since the cyanotype process creates a relatively high contrast image, you could try a fine screen over the medium as is used in the printing trades to prepare plates for photographic reproduction.

This may now be my favorite camera as well. Thank you for sharing such a wonderful experiment.

The blur on the edges is called comatic aberration. You can fix it with a couple extra lenses, a Plano-convex and a Plano-concave one. I suggest talking to people that build telescopes, your aperture is large enough to fit somewhat in the same realm of imaging. Also, you can look into how tele lens are set up. You can ignore all the chromatic correction lenses and only try to mimic the coma correction, since you're imagining one wave length.

This is fun! Suggestion #1: Use photographic paper instead of that cyanoshite. It isn't fast, a mere ISO 3 or so, but way better than what you have now and all you need is developer (and stop?) and fix to process it. Rince it well. Suggestion #2: Use large format film and develop it yourself and then make use of contact photos on photographic paper. Since film has way higher photosensitivity, this eases the job a lot Suggestion #3: Drop the lense and use a pinhole instead. You can find tons of pages describing pinhole cameras, but the basics are just focal length == length between hole and film (or whatever) and aperture == focal length / diameter of pinhole. So a focal length of 200mm and a pinhole of 1mm gives you an aperture of f=1/200. With pinhole, everything is in focus, ish, since there isn't a lens, but it'll get more blurry the larger the larger hole. It'll aso get more blurry with a smaller hole, just as it does with tiny apertures with a camera with a lens - all because of diffraction. Good luck and happy photographing :)

This should be a MANDATORY PROJECT in all schools. Just 1 example how so many things nowadays are being taken for granted, yet centuries of research, development and try&error went into all of those...

I've seen someone turn an entire hotel room into a giant pinhole camera. He made a pinhole using black paper on the window with a hole and covered the back wall with numbered sheets of print paper, then reversal processed and re-assembled them. I really like the idea of large, impromptu cameras.

We used to have one of these that my grandfather built. It took photographs that were used in the science journals of his time. I never saw it operate but it apparently took amazing pictures for it's day.

Suggestion for the next revision. Mold paper into a spherical shape to address the focus issue created by the large aperture. Would make for cool wall art also! Can’t wait to see the next version!

This isn't about this video specifically, but I'm really glad I found this channel. I find myself "running out" of things to watch on KZfaq because it's terrible at recommending things to me, but luckily I got the golf ball simulation video from another coding video, and decided to check out the other videos. I'm constantly looking for channels that feel like worthy additions to the "Steve Mould, Applied Science, Stuff Made Here, Veritasium, Smarter Every Day" category, and this is definitely it.

17:26 I have the same photo!!! "Pale blue dot". Also at the bottom of it, I have the quote by Carl Sagan. You're a very smart individual with a great grasp on sciencetific method and much more. Keep up the GREAT work!!!

Applied Science had a video about photolithography, and in that they used a vaccum to hold the film against a backplate -- maybe you could do a similar thing to avoid having to use tape?

1:57 THE SACRED TEXTS (seriously, one of the best electronics text books out there)

What a fantastic video. Very interesting and enjoyable to watch.

So this might be a whole new project but could you capture the image on thermal paper and use a mirror to transfer the image onto cyanotype? It might speed up your development time, plus it would allow you to print a "positive" onto the cyanotype, in addition to allowing you to print a thermally captured image onto UV sensitive paper (which just kinda sounds cool).

To avoid the sun setting your camera on fire, maybe install some kind of "barn doors" into it, similar to movie cameras, to mask everything not included in the final image. As long as you're not shooting towards the sun, you should be okay.

I have watched this video I think 3 times now, and I find it ammusing that you have, in the last 3 days, basically tippled your sub count to where you need to do the 2^15, and are half way to needing 2^16. I wish you luck on getting those done soon.

the Fahrenheit joke got me! i friggen love it!

Oh man, you yourself are up there with these different breeds!

and its already time for 2^15, congrats!

If I lived anywhere near the same continent, I'd make my best effort to add you to my friend list. Highly intellectual and approachable character. I love your videos.

congrats on 2^16 subs!!

Where did you source your lens from and how transparent is it to UV?

You had me at lights itself on fire 🔥

Absolutely wicked graphics!

This channel is awesome, you're going to get big i feel it

OK, I have a couple of suggestions, coming from someone who has 1. Done cyanotype, 2. Built my own 20-24 camera in the past from black foamcore, and 3. used ULF cameras for a long time... Back when I was a kid, we did something similar to what you are doing, but we used a overhead projector to do it. You know, what I'm talking about? One of those things with a light source and you put a piece of film on it that you can draw on and then there's a mittor and lens aboe that you can aim at the screen and focus? These things a PERFECT for going the other direction. You basically need to make a black tent for the area from the lens down to the light table, and then you place the cyanotype paper on the light table (and don't turn it on, the light comes the other direction). It becomes a bit of a camera obscura, and all you need is a white piece of paper to focus and compose on before you put the cyanotype paper in there. The lens is pretty large, and who knows what the aperture is??? But it will have some chromatic aberrations in it, so it isn't perfect, which produces some of the dreaminess that you may like (or not, of course). The exposures are likely to be much shorter because the lens is going to be reasonably fast. If you want to try to improve the image quality and start to eliminate a lot of the artifiacts that you nay not like (towards a "perfect" image), you will need to redesign the camera to ensure that the light that is coming inside the camera but isn't part of the image on the paper is dealt with a lot better. That light is a source of FLARE. Not necessarily the lens flare that you think of from J J Abrams' movies, but a general loss of contrast in the image that will sometimes be uniformly distributed, but sometimes be concentrated on one side or another. This is in part due to the light getting in through the lens and then bouncing around inside before eventually hitting the cyanotype paper as randomized (not image-forming) light. Eliminate that, and you will have a lot more contrast in your images. I can get into why but the key to focus on is eliminating that extra light wherever possible.

Really cool pictures! Also they look like the cover for a Jandek record.

Interesting video, I've been wanting to do similar for ages. Have you thought about doing a daguerrotype image on glass, and then taking a blueprint from that? It's been a while since I looked at it, but I think you would have a non-inverted image as a result.

First time viewer. Great video! Awesome intro! Easy easy sub.

I’ve always used cheap glass for my contact printing frames. I have a book on alternative photographic processes and it is avid about not using acrylic.

I took screenshots of your subcount separated by like 10 mins. 300 more subs. GG man.

Just discovered your channel and I'm hooked!

How about putting the cyanotype chemicals on glass to form the negative, then exposing another sheet of cyanotype paper through that to get the positive? No fuming mercury. Perhaps you could also experiment with using coloured filters so your negatives are colour specific, then combine them (can't think how except in a computer).

Honestly surprised this channel doesn’t have a million subs yet. I’d give it another year or two before that’s rectified.

Your channel is massively underrated. You need more subs! :) Btw try finding a cheap lens for 8x10 photography. You can try not lighting it on fire by designing a “perfectly” matching lens hood. Also try looking into daguerreotype photography, since it also has a quite low ISO and might give you some inspiration. Hope this helps a bit:)

I wonder whether using an imaging fresnel lens would allow you to use a significantly larger lens, allowing more light in and cutting down on exposure times, and possibly reduce the spherical abberation (though trading it with the artefacts from the fresnel ridges).

Can you help reduce the spherical aberration by using an aspheric lens? Or maybe you could purposefully bow the paper by using a jig? Love the video as always!

A few suggestions: 1) did you test the lens for UV transmission in the same way you tested the acrylic? if it fails find another lens. 2) Hold the paper flat using vacuum against a 3/32" acrylic "back board", that you sanded, or lightly sand blasted to make it a "ground glass" focusing screen. By mounting it in a sturdy wood frame with 3 bars behind it spaced about an inch back, and 9 small (#4 of #6) 2" long flat head screws, you could "dish" it to match the curvature of the lens's image field. For a vacuum pump, perhaps one of those sold to suck the air out of a home freezer bags that is powered by 2 AA batteries, and after 15 seconds or so, run it on just 1.5 volts perhaps via a voltage reducer and a 12 V car battery, or a bunch of "D" cells, wired in parallel. Another option is a small home aquarium air pump in a sealed "Coffee can" with the outlet hose to air, and the "coffee can" being in vacuum, would require 120 VAC, although I think that there are some made that run on batteries for people with expensive fish in case of power outages.

Great video. I've always wanted to see a cyanotype camera in action. It may be worthwhile considering curving the film plane. Also using a splash of hydrogen peroxide after washing will bring out the deep blue quicker and so give you a better idea of final contrast.

I think some blinders on the outside of the lens would go a long way to help the whole trying to start itself on fire thing. Like what you see on broadcast cameras to block stray light

Very cool concept, I am actually surprised at the quality you were able to achieve. New to your channel and love your videos. Also I have two suggestions I could think of: Any reason not to use cloth instead of paper as the shroud? Could you incorporate a flash using magnesium to help the ISO?

I made a pinhole camera out of a Pringles can back in the day, very cool fisheye type pictures as the photo paper inside was curved to the inside of the can.... Much smaller aperture tho. Keep up the great work.

love your excitement good presentation

You could try glass instead of acrylic to keep the paper in place.

That Art of Electronics reference brings a tear to the eye

This is so cool! I've watched a few of your vids and have really enjoyed how you explain the processes going on. It makes a lot of sense. Thank you! Bridges over flowing water make cool subjects. But if you want to mimic the first photograph of a human, get someone to get their shoes polished for a while :P Also, since you clearly love PPE, be careful cutting MDF, it contains formaldehyde.

You could try a bigger lens to collect more light. Loved the video. I bought some paper like this for a project with my daughter. Super fun

Great video! I think you’re still getting a lot of light leak through the box. You might want to double up the poster board with overlapping layers. Also, covering the lens before and after you’re taking your photo would probably help with as well. Any time the lens is open that paper is collecting light

I would try a lit city at night. Mount it somewhere hidden, overlooking a city, and go remove the lens cap at dark, and replace it before sun up for a few nights. I build a light-sensing shutter.

7:39 if you wrote it in mirror text, then flipped it so the ink side is touching the paper, you'd get a more crisp image. 8:15 If you print the graphic mirrored and expose it with the ink side down, that will increase the fidelity of your exposure. Basically, the light leaks under the graphic through the plastic carrier. The thickness of the transparency causes the "smudging", blurring the shadow as it's floating above the paper. I'm a graphic artist. I used to expose metal plates for pad printing. I used to send my graphics to a shop that created masks using a photo process. I'd send the graphic flipped (mirror) so that when I apply the film as a mask, the ink side would be the side touching the masking gel. This would give me higher resolution crisp graphics during exposure.

You could theoretically have the paper resting concave, inside the aperture, to make up for the lack of focus that is around the center of the image.

Great video. I have been working with this process for several years and love making "in camera" cyanotypes. Something you might consider is trying "Nature Print Paper" in your camera. That is what I have ended up using for the last two years or so. I can get a great image with an 8 hour sunny day exposure.

amazing project, also love the shirt!

Thankyou, I appreciate all your content

These videos should be getting millions of views !

Since it uses UV light to create an image, could you use something like Wood's glass since Acrylic isn't very UV transparent? It's opaque to transparent light, but you could slide it in after you focused your camera

The first large format prints I did were on paper as well. But I did dry plates later. But you should use a ground glass viewfinder, which is a whole lot more fun.

Great vid! I would make a lens cap and lens hood to fight those pesky rays of light. also is there a way to slow down the developer reaction? It may allow more detail and contrast to form on the print.

It would be cool to set it up for a camera shot but also place a print slide on the paper. You could essentially photoshop in the silhouette a person using the slide against the backdrop of scenery or something. I used to play around with these blue print sheets as a kid. I must have gone through a pack of 50 pages in a week when I first got them. I love simple kits like that. It was more fun than my gameboy honestly, because I had to think about what I wanted to expose next and how to create cool prints.

After the introduction I was kind of expecting you to somehow take the picture three times with R,G,B color filters before the lens and paint over with the cyano, magenta and yellow to get the a colored picture, but i guess that is unfeasible Great work!

I had the honor of working on 120 year old glass plate negatives. 12x16 inch plates. Just lay them on the photo paper and make a contact print. I was very very careful. The quality is next level.

Have you considered adding compound or macro lenses? Maybe apply the reactant on the paper in multiple layers? Try applying the reactant in a spray using an airbrush?