Antique 4x5 camera creates 20 micron photolithography masks: Super tiny tax form

[@PracticalEngineeringChannel]

This is crazy. It's practically a culmination of everything you've been working on for the past however many years. Every time you introduced the next step, I just had to laugh at how much prior knowledge (and prior failures!) went into each one. As always, awesome work.

[@zyxwvutsrqponmlkh]

Oh come now, he didn't even do electron beam scribing.

[@HelloKittyFanMan.]

Oh, cool, look who's here! I love your videos too! Hey, you're Grady, and that is Practical Engineering.

[@darkquaesar2460]

Hey practical engineering, are there any physics and chemistry books you recommend?

[@mas5.545]

Practical Engineeringy yes absolutely amazing! He just summarized up 5 years of my university studies some years ago in 30 minutes, well explained, well structured and as always with passion! A great Thank you!!! Well done & keep continuing ;)

[@ralanham76]

@@zyxwvutsrqponmlkh so now you know the next step

[@yoppindia]

Always read the fine print.

[@Dust599]

Yea the lawyers will love this, fine print you can't even see, let alone understand.

[@MichalCanecky]

Or you may agree to become a human cent iPad

[@Raven-fu1zz]

@@MichalCanecky yeah but the cent iPad won't read

[@IudiciumInfernalum]

It would be rude not to after all the work that went into it.

[@switchthechannel6317]

What is this? Fine print for ants?

[@thethoughtemporium]

OUT-STANDING. Absolutely incredible work. When you first sent that test slide image over I was already thrilled but this is so much more incredible than I ever could have imagined. The use of the camera was brilliant and the results speak for themselves. I can't wait to get some neurons growing on these once the final arrays are made. Thank you so much for going to all this trouble, it's greatly appreciated!!!

[@rojirrim7298]

Daaamn this collab is going to be awesome. Can't wait for the results!! Thanks for the effort guys

[@Falcodrin]

Accidentally came across this vid a while after seeing your sputtering vids. Cant wait to see if you succeed!

[@CamRStanford]

When did this happen, all my favorite science channels in one place, Lubb youse guys!

[@ruokblah3010]

The colab we never knew we wanted!!!

[@CamRStanford]

‘The collab we never knew we wanted-The collab that we needed’

[@panykfelidae9018]

As a terrible chemist, a half baked engineer and a professional photographer I really, really loved this!

[@askquestionstrythings]

As a terrible chemist, a former professional commercial photographer, and a newly degreed mechanical engineer I also really enjoyed this.

[@GucciCaligula]

As a terrible engineer, a half baked photographer, and a professional chemist I also really really loved this!

[@rockrl98]

@@GucciCaligula As a professional terrible, and a terrible terrible, and a terribly terrible, I also really enjoyed this.

[@TomCardinali]

As the son of a professional photographer (where I grew up using all the 4x5 hardware and processes he demonstrated, and then later in college) and a 40yr professional microlithographer, you hit the nail on the head with this video. Pro tip about the film holder dark slide (what we call them, not 'shutter')... The end with the handle is bare metal on one side and black on the other. Put the black side facing out when loading with unexposed film (that's how we oriented them) then after exposure flip it so the metal side faces out. The bare metal side also has notches in the edge next to the wire bail in the middle. Then when you're on a job you can quickly tell exposed and unexposed frames on sight and the notches let you feel it in the dark. Loved this.

[@RobertSzasz]

@@TomCardinali do you use a focusing mask during any setup processes?

[@sheemondallasgeorgia]

Film Holder: 1. It is designed for thick Estar (polyester) film. 2. You need to offset the thickness by putting 2-3 layers of film in the holder. 3. Vacuum back were used in WWII for areal photography. 4. You do not use a vacuum cleaner, you use a vacuum pump based on a refrigerator compressor; they are very quiet and pull higher vacuum. I can supply you with a simple layout. Processing Film; 1. You must slide the film into the developer, not immerse it. 2. You must agitate the film by lifting corners of the tray in some pattern. Other: If you see Neuton rings, your film is not making even contact. Expect refraction. The color of the ring is ¼ wave length of the light color. Avoid by using Anti-Neuton glass, or sprinkle dry talcum powder on the glass then gently blow it off. All developing must assure flow of fresh developer across sensitized layer. Film, resist or anything else. Explanation available. Correct these errors and you will greatly improve your results.

[@bonjourmssr]

Thanks! I guess that's why photographers used to be called "operators"

[@MostlyPennyCat]

I miss the smell of a darkroom. Hanging out in a red, dank and vinegary cave.

[@maxk4324]

While your advice appears to be incredibly professional and accurate (I assume, I am not a photographer), and none of it is bad advice, regarding point 4 of the first set, you do know that he actually has extensive experience in vacuum technology right? Like this is a guy who built his own scanning electron microscope.

[@MrMegaPussyPlayer]

_"4. You do not use a vacuum cleaner, you use a vacuum pump based on a refrigerator compressor; they are very quiet and pull higher vacuum. I can supply you with a simple layout."_ I don't think the higher vacuum is needed. Might even counterproductive. But it is for sure less loud.

[@rationalmartian]

This is one of the strengths of KZbin, in that a collaborative acumulation of knowledge becomes virtually inevitable. There are so many interesting and interested geeky, nerdy, techie folk around more than happy to help and throw in suggestions and tips that may themselves been built up by successive generations. It is wonderful thing to witness. Everyone pretty much is dancing on the shoulders of the previous generations, and trying to improve on them. In turn passing them on to the next. Here it is possible to witness it happening.

[@R3VISION3]

It's criminal that this channel is still under 1 million subs.

[@yoppindia]

people dont have patience to read fine print

[@rationalmartian]

It is indeed. This is a truly remarkable channel. Kind of makes most teachers, lecturers and supposed professionals look decidedly weak uninteresting and almost not trying.

[@rorypenstock1763]

@@rationalmartian Some of them, sure. But don't forget, Ben gets to edit himself!

[@AntonBabiy]

It's not a lot of subs but at least the ppl subscribed usually are tech inclined and don't just come to leave bs comments

[@wizerdman3054]

well I don't think any lawes were broken he just made a microscope

[@typha]

So "focal plane" is actually one of those lies that we tell people to make things simpler. Focal "planes" are actually more like focal curved-surfaces (rotationally symmetric ones). Higher quality lenses are typically designed to have more planar focal "planes". So that could be part of your problem too in addition to the film bowing. This sort of aberration is commonly referred to as field curvature. It might not be a problem for you, your lens might be good enough for this to not be noticable, but it could be part of the issues you were having. (Plus I believe that the effect is minimized by stopping down, so since I think you said you were very stopped down, field curvature probably isn't an issue for you, but it's something to be aware of)

[@jamesdriscoll9405]

f11 iirc

[@iNerdier]

James Driscoll if he is at f11 that’s actually not particularly stopped down in large format terms, an easy thing to try might therefore be a smaller aperture (with some kind of lighting rig at a 30 degree angle to remove reflection). It’s also kind of funny to see him doing as a special process what was daylong work for people thirty years ago.

[@davesmith9325]

Strictly speaking yes all lenses produce a curved image plane (its never a simple radius), however the lens design is a compromise to be acceptable on multiple metrics (cost, speed, resolution, image circle etc) and will substantially flatten that focal surface, to the point that when stopped down the residual error is acceptably small cf. the resolution of the film. Different lenses are optimised against different design goals, but you might want to think about what eg the famous "planar" design of optimising for 🤣

[@hemerythrin]

Thank you Haruhi, very interesting.

[@JohnDlugosz]

@@davesmith9325 Probably the tolerance of that camera and lens was designed for casual viewing of prints. It's probably far sloppier than what he's trying for, and would still look fine if you're looking at a portrait at reading distance (not using a magnifier or hunting for subtle flaws).

[@HuygensOptics]

Great video! If you want a higher resolution, you could try direct exposure of the photoresist on glass inside your camera and use violet or uv-illumination for the object pattern. With an old canon ft lens i could in this way achieve 2 micron resolution. With large focal distance lenses like the one you are using that would be hard to achieve though.

[@Keechization]

Just in case you get the bug to shoot large format in the field, the darkslides on the film holders do indeed have a secondary way for a photographer to keep track of exposed and unexposed frames: there are textured bumps and a bright side (if the darkslide is metal it's unpainted, if it's plastic it's white). so you're supposed to draw the slide out completely when exposing, and put the slide back in white + bumps side out to mark that it's been shot.

[@dylangergutierrez]

Came here to say this, thanks for saving me the trouble!

[@ruhnet]

Lol I put the bumps in when exposed, out when unexposed. 😁

[@RalphWLundvall]

If the dark slide shows dark, the film has always been in darkness (unexposed). If silver or white the film has seen the light. That is opposite of the general usage but it makes sense to me. If I ever get an assistant, they will learn this way of the dark slide.

[@AureliusR]

@@RalphWLundvall It makes literally zero difference, as long as you are consistent.

[@l3d-3dmaker58]

applied science x thought emporium crossover? EPIC!

[@Tony-nl6pf]

Thought emporium has good videos but he doesn't respond to comments and ignores emails. He fails on connectivity.

[@officialniknak]

@@Tony-nl6pf he's busy

[@miftahyf2811]

As an engineer and a film photogrpher, you have my respect! I love looking at how much effort you put in to make piece of photograph (a very small one)!

[@cameronrad1]

What is this? A tax form for ants?

[@AppliedScience]

For the thumbnail, I tried to take a picture of actual live ants on the miniaturized tax form. Even by just cold-stunning the ants, and having them wake up, and walk away, it still looked like a dead insect / blob on the form. I still have a great imagined image of insects next to tiny LEDs, tiny ICs, microdisplays, microprint, etc, but have never been able to capture anything that looks good.

[@Tahoza]

It's going to need to be at least... 3x this size!

[@samuelb6960]

Didn't you here the IRS is taxing ants now.

[@letsgocamping88]

kzbin.info/www/bejne/apqcfJpujZmdZ9E I heard your comment like this

[@Matt-uf2nc]

@@AppliedScience Can you metallize the ant and get a metallized slide with the tax form and put them in the electron microscope?

[@runforitman]

I love seeing such old technology finding its way into quite advanced experimentation

[@noeoep]

The Fresnel lens isn’t there really for focussing, it’s to allow the photographer to see the whole frame at the same time while framing the shot. Thanks for this short but comprehensive overviw of the analog photography process!

[@chrispza]

This made me so nostalgic! I operated Klimsch large-format plate cameras (film-size, up to broadsheet newspaper). Two things: Lighting-try high-intensity quartz halogen; it has a wide-spectrum output, up into the ultraviolet, which should appreciably shorten your exposure times. Secondly, for exposing the photo-resist, a sheet of pure polycarbonate will pass much more UV than window-glass. Oh, one last thing: while I am not recommending the use of an optical bench, for super-critical applications such as yours, a sturdy table might present better, more repeatable results. Thank you for a super interesting vijayo, and I wish both channels the very best of fortune.

[@jonanderson5137]

I always enjoy a good AvE crossover.

[@Khrrck]

You can also get very high intensity UV lamps used for disinfecting off of Ebay, but I believe they may be florescent, so optics would be required. (Note if anyone actually buys one - they are extremely hazardous and can burn your eyes and skin without you realizing. Research safe and proper use before turning them on.)

[@BrilliantDesignOnline]

You explain it all so casually and with only the practical detail we need, including your observations of things we would never notice (like the dust factor and the readout change due to the sensor being covered) VERY cool. Thank you.

[@marcmarc172]

I can never guess the next project yet EVERY TIME it makes my jaw drop! You guys GOTTA share this channel, cmon!

[@ryangriggs5767]

The vacuum film holder is exactly how the large format cameras in print shops used to work. Amazing video!

[@madome3117]

I was really shocked, when you said: see you next time. I wasn´t prepared for this video to end so quickly. Somehow this half an hour video felt like 10 min. Great work and I really appreciate you attention to detail

[@11kungfu11]

Im becoming more and more convinced you are the world's best money forgers and you are just slowly handing off your skills to those of us who can read between the line. DONT WORRY I WONT TELL.

[@jimurrata6785]

My life in the '70's.... Commercial art & stats. ASML is literally 1/4 mile from me right now Photo lithography has come a long way in 40 years. Ben, as a material science geek, I love every video you release. Admit to being jealous of the tools you have to produce them

[@BuckJolicoeur]

Words cannot express how impressed I am with your channel. You cease to amaze me. As a Graphic Designer who designed masks for etching masks, this is brilliant. Thank you.

[@therealmdavey]

First off, great content. This was the sort of thing I lived in the 70’s through the 90’s in the printing and photography world. A few notes that you may find useful. If you can get your hands on a 11 or 21 step grayscale to use on your wall, it would be a great help for setting exposure and maintaining control. These were standard on any litho exposure in the printing industry in the 80’s and 90’s. The steps make for easy adjustment of exposure between steps. Also critical for consistency and calibration of exposure. Finally, if you could make a small vacuum frame for exposing the glass slides it would be helpful. The Newton rings can actually cause small exposure variations through the rings. This was a problem we dealt with in the printing industry.

[@austrianwing]

Funny, I have been thinking about trying large format photography for a while now. This has turned out to be a better explanation of all of the mechanical details of going through that process than any purely photography focused tutorial I have ever seen.

[@sonovoxx]

I'm in awe of the persistence, never mind the process. Incredible forensic detail given to every step.

[@nohphd]

I’m stunned to have stumbled upon this video. I’m getting ready to retire and contemplating a project using pretty much the exact same processes you’ve explained here. I’m sure this single video will save me years of trial and error. Thank you so much!

[@orlandop2265]

Nobody need to sleep when can make "20 micron photolithography masks".

[@rogueanuerz]

@zztop3000 no , corona virus is much more tiny shit bruh.

[@nomadben]

I'm a huge photography nerd and I've been curious about photolithography, so this was a really fascinating episode. I love how clearly you share the information and demonstrate everything in a way that's easy to understand. Thank you Ben, I always appreciate how much there is to learn on your channel.

[@JohannSwart_JWS]

BTW, a tiny laser spot on the wall might make your focusing easier. I tried a red one (ca 650 nm), and it seems to work just fine, even though diode lasers suck. A well collimated HeNe, which I'm sure you posess will be perfect.

[@devrim-oguz]

Yeah, especially when you remove the lens of the laser diode, the light comes from a particularly small point.

[@RobertSzasz]

Add a focusing mask and that works great. (I used the laser spot on a wall to test out various focusing masks and then fix an incorrectly set DSLR ground glass.

[@hypt0ny]

You have one of the most inspiring channels on KZbin Ben. You can really show what a devoted backyard engineer can accomplish with only will and perceivance. I am truly amazed by your projects and I've watched every video you have uploaded. Thank you for sharing all of this to us.

[@JasonOFlaherty]

This was really interesting. I'm glad you showed all of the steps completely so we can see the whole process

[@BarnacleBrown]

I don't know why but all the sounds this camera makes are so pleasing. The shutter slides click and slide so nicele, the levers and clips all make such a nice clicking.

[@mute8s]

As soon as you started talking about photos and microscope slides Thought Emporium came to mind then you mentioned him. Glad to know I wasn't wrong. 😉 I also saw Technology Connections is one of your patrons which was also cool as that is another channel I'll drop most things I'm doing to watch. Keep up the good work Ben.

[@Piipolinoo]

You never cease to amaze me! People also need to remember that you did not only create a 20 micron photolithography mask, you also used it to sputter a metal layer in a sputter chamber you've built yourself. Also, in principle, if you ever wanted to, you could have a look at it in the SEM you've built a while ago as well. YOU ARE A LEGEND.

[@electronicsNmore]

Incredible. A very involved process that requires a lot of knowledge, but yields amazing results!

[@copelandart]

That takes me back to my early days in a print shop! I ran the camera department, which had a giant version of your view camera, vacuum back and all. Hand processed much larger sheets of litho film (up to 18" x 24") in temperature-controlled sinks. We also modified the camera, making it into an enlarger, so we could make up to 42" x 60" prints. Sometimes, I miss those days......

[@lucuslanders8033]

Pro Tip: one side of the dark-side is white, and the other is black. When you load the film, have the dark slide showing white, and after you shoot it flip it so its showing black. That way you know if its been exposed or not.

[@michaelcoyote]

I heard that and rushed here to make sure someone pointed this out,

[@batchint]

this is probably the first camera guide I've seen that goes into some depth but in the mechanism of the photo machine

[@wileecoyoti]

About the difficult focus: what about making a "false star" at the target surface (possibly by poking a pinhole through a dark part of it and planning an led behind) and using a bahtinov mask over the camera's lens? Should get a physically perfect focus that way, same problem and solution used in astronomy. Very cool work as always!

[@jonanderson5137]

Seems like a smart solution.

[@brettsuydam]

For long exposure large format photography, I would also recommend a heavy duty wooden tripod (hard to find these days) to absorb vibrations coming in through the studio floor... Especially when trying to preserve very fine resolution without any motion blur.

[@FG-Supercharged]

You're a brilliant man, Ben. Thank you for sharing your knowledge and experience!

[@DanielLopez-up6os]

Still super amazingly sharp. And the Reciprocity factor, now clicked and it makes sense why my film images in winter were worse than in summer.

[@J_CtheEngineer]

“So I made a vacuum film holder” you know. As you do.

[@DavidLindes]

Loved this bit! (11:53 by the way)

[@Brewbug]

Lol it’s what I was thinking he should do just like the old Contax RTS III did but I couldn’t believe it when he said he’d actually done that. Wow.

[@Holey_Moley]

This reminds me of when an older PCB engineer described how film was used to miniaturize the traces that were first laid out using masking tape. The principles are the same , but this video has the advantage of using a printer instead. Really cool! Thank you for making such a thorough video!

[@MyAvitech]

So what did you do during quarantine? *The world:* Binge watched Netflix and tried not freaking out. *Ben:* Just messed around in the shop making 20 micron photolithography masks that are used to make titanium electrodes that attach to neurons.

[@recklessroges]

I wonder what the highest density of data can be achieved with Ben's method. (Some sort of 2d barcode to backup important data, or have the data in rows and data with vertical lines being a one and the absense being a zero + then a "second layer" of data could be written by rotating the vertical lines like the hands on a clock, {though the data could be written in one pass}.) How easy would it be to read the slides?

[@patprop74]

lol sounds about right

[@EggBastion]

This guy! Hell, and I can't be bothered to even make my damn food any fancier'n usual *_`: /_*

[@rip8641]

I aspire to be as motivated to do cool things as Ben.

[@VerstehenSieMathis]

@@recklessroges Isn't that pretty easy to say? For a simple matrix of dots and non-dots of 20µm, it's 1250*3750 bit = roughly 0,5 MB on every 25mm*75mm microscope slide. It's denser then floppy discs.

[@bipolarchemist]

Brings me back to the hours I've spent cleaning microscope slides in the past. My typical routine was a good mechanical scrub with soap and water followed by a 10 minute or so dunk in piranha solution, rinse with a healthy amount of DI water, sonication in IPA and then acetone and finally drying under vacuum. That provided a nice hydrophilic surface for functionalization with silanes. Thanks for the excellent video and walk down memory lane.

[@Wingman4l7]

Methods similar to these were used to make microdots -- millimeter-size pieces of film containing espionage-related stuff: en.wikipedia.org/wiki/Microdot

[@pamdemonia]

Just finished (at midnight + 15 minutes -- sheltering in place, obviously) watching Oxtools fix the most amazing level and I see this. Plus new AVE and This Old Tony earlier. Glad to see some of my favorite guys are okay and doing interesting things! Tomorrow I am attempting an orange chiffon cake in a countertop convection oven as covid-19 project. I'd send all y'all a slice if I could (and it works out.). Thanks for helping us stay sane!

[@wimwiddershins]

There's something about watching you achieve results (that usually require a clean room and a corporate research budget) in your garage using home made and antique equipment.

[@stargazer7644]

I’m amazed that people don’t realize kids used to learn to do this stuff in high school photography class. I did, in the 80’s.

[@bobsagget823]

@@stargazer7644 nobody cares boomer

[@stargazer7644]

@@bobsagget823 Your math skills need some work.

[@tootaashraf1]

@@bobsagget823 Shut up

[@johnpossum556]

Excellent work, Ben. I worked with an even larger form film when taking Graphics Art classes. It was standard notebook sized. But the real fun and magic was copying that onto metal lithography plates. So much energy was needed that the machine was basically a carbon rod arc welder light source. It had to be adjusted by looking at its shadow on the white concrete block wall then exposed for 2.5 minutes. Then developed by using a bunch of chemicals that smelled like strawberries. In the end the result was 250 runs on the motorized lithography press. Two sides, 500 total. Very very old school. ( we also learned to set lead type in that class )

[@BenNBuilds]

Sweet! I can't wait to see the final product!

[@origamihawk]

Woah you're still alive! I ran into your channel like 4 years ago while working on some ROV stuff, interesting seeing you pop up here.

[@EpicHeroSandwich]

I used to do photolithography masks for a living, engraving specific-micron textures on specific surfaces of finished parts, this is neat!

[@Beregorn88]

"it has a really high contrast, measure to prevent halos from back reflections, it is not impressed by red light and it is even transparent to UV! How convenient!" Funny, it looks almost like it was designed for the production of photolithographic masks... :)

[@JH-tc3yu]

That's literally the next sentence he says.

[@AnianBrosig-yv3jn]

wow, old cameras were much cooler than I thought :) I always am amazed with all the little tricks people come up with

[@GoldSrc_]

This channel always delivers, it's just amazing. Keep it up :D.

[@zacharykrawczyk3942]

Wow it's really cool to see so much collaboration between makers on KZbin. It's like you're all neighbors

[@simon-d-m]

Way back in the late 1970s or early 1980s I saw a WWII Luftwaffe reconnaissance camera in the London Science Museum. The lens, and I think the whole camera, was by Carl Zeiss. It has a huge film format, at a guess about 30cm square. It actually used roll film, not sheet, and the spools were about 70-80mm diameter, which must have meant that each frame was truly curly!. So it, too, used a vacuum hold down system - that was the first place I ever saw such an arrangement, although I think it was standard for things like integrated circuit mask making and other lithographic techniques (update: I think it was this one images.app.goo.gl/ukyVFRdytZBJKSoL7 but I can't find it in their on-line collection so it may have been borrowed from elsewhere for their photography gallery, and anyway they now have a separate photographic museum in Bradford, Yorkshire). In the 1980s, Agfa used to make its lith film available in 35mm format too: I used it to make sharp masks of lettering for titling audio-visual presentations, and Ithink I may even still have a roll somewhere! I remember it as very "slow" (ASA 3 or 4), but the results were extremely crisp, as long as you developed it carefully. Apart from the ease of lab handling, the big advantage of it being orthochromatic was that chromatic lens aberration didn't matter as much as with panchromatic film. That was a thorougly enjoyable video - thanks very much for doing it!

[@dennyoconnor8680]

Good memories. I'm 82. I did my first darkroom developing (Kodak Brownie camera) in 1953. I still have some 4x5 Speed Graphic cameras and complete darkroom equipment / enlarger. Yeah, Ortho is good in that you can use a safe light. But, after a big chunk of my life messing around in darkrooms I don't even think about a light. Do it by touch. The key is everything organized on the bench in the same position and orientation every time, no exceptions. Yes, temperature control in the darkroom is everything and for outdoor temperatures you use the film manufacturer tables for exposure correction (and do tests). You get an attaboy for teaching yourself what is becoming a lost art, large format B&W phototography.

[@oghry]

Very cool. With this lithographic setup you should make your own Intel 8080

[@MusicBent]

Alexey Dubrov he already has built most the the technology needed. His biggest difficulty would be in the many layers required and keeping them aligned through the process. Let alone obtaining the lithographs required

[@otm646]

The vacuum film holder in that format is making your life more difficult. Sinar has an adhesive holder that works great. You really only need a vacuum when you get to the massive formats like 8x10.

[@joemcguckin6151]

You've managed to re-invent the Graphic arts process camera. Every printing house had one (before the printing industry disappeared)

[@katelikesrectangles]

Just incredible. You've built on so much of your prior experience for this, and it's lovely to see so many topics come together in one process. Really good work.

[@ramjetross]

Now you can photolithography and etch your ITO glass to make some interesting AC electroluminescent displays with your ITO-PEDOT-dielectric-emitter-copper devices. Maybe a microdisplay.

[@jonanderson5137]

Now I have to go check exactly how small smleds can get.

[@colincolin6422]

Hi Ben, Working in microelectronics here. I do a lot of photolithography and photoresist coating. To spincoat photoresist uniformly on wafers you have to put the liquid on the whole surface of your sample prior to spinning. Only once the surface is entirely covered you start to spin. The acceleration should not be too important like 700 or 1000 rps². Maybe you are starting to spin before putting the photoresist because you had some of it getting under your sample? Your equipment must be perfectly leveled to avoid that. Also, you should not put too much liquid and avoid any air bubble before starting to spin. This method works perfectly on round wafers but also with odd shapes like rectangles. Your work is extremely impressive, I love your videos !

[@Homicidalburger]

The fresnel lens is more useful to have an evenly lit view over the ground glass. My Graphlex that uses a ground glass(non fresnel) will barely show any details on the edges of the frame.

[@colinholloway6252]

Seeing the camera and the loop for fine focusing reminds me of seeing videos of wet plate / tin-plate photography. Beautiful images that either use long exposures or flash - blue sensitive. They're all on KZbin.

[@SimoWill75]

You've rediscovered all the problems we astrophotographers used to have. Great vid. Cheers. Edit: do you know whether the film you're using can be gas hypersensitised to combat reciprocity failure? Might be worth investigating, and pretty simple process for someone like you ;)

[@creepyloner1979]

easier to just wait an extra 10 seconds, or buy better lights.

[@NorwichCameraCompany]

Why....just buy a faster speed film like pan F 50. You dont need litho film for something like this.

[@SimoWill75]

Yes, good point re time&lighting. Not much point saving seconds vs hours(astro). Regarding PanF, my crusty memory says it was pretty low resolution? There was a reason I filled my fridge with D100 all those years ago, I think that was why (better sharpness & resolution) Think I might even have an old 120 roll of TechPan tucked away somewhere.

[@stargazer7644]

Exposure time really isn’t a problem here. Plus I believe gas hypering makes the grain larger.

[@craigs5212]

Very nice Ben, brings back memory of making lots of PCB's in the garage with the same process. This was back in the hand tape days, no fancy PCB design tools and get your PCB's form China in 5 days for $2. Didn't have the camera so I sent the 2x tape ups out for reduction negatives, but had to make positive contact copies with ortho litho film for the positive Shipley AZ111 photo resist. I found the trick with the spin coater was to wet the entire board with a cotton ball before starting the spinning, adding more resist as you go. I think the viscosity gets too thick as it self drys towards the edge of the boards. Also make sure you arrange your image so the emulsion is down against your slide for the UV exposure. It's amazing how well the resist striped off under the Ti coating, the edge of the resist has to be exceedingly thin. Nice to see Freestyle is still around and still sells litho sheet film.

[@CaptiveReefSystems]

I saw Though Emporium's first attempt at the neuron x microelectrode array and was *very* interested in their progress! 👍 I hope you guys succeed and will keep an eye out for updates!

[@charlesworton4020]

Well, I'm blown away. The whole sputtering thing at the end was completely over my head, but I loved it anyway. Vacuum was commonly used in large process cameras (shooting 16 X 20 film), used in print shops. BTW, if you check the dark slides on the film holders, you'll see that one side of the metal tab you grasp to insert the dark slide is aluminum colored, and the other is flat black. The convention was that when you inserted fresh film, you would have the aluminum side facing out; when you exposed it, you would re-insert the dark slide with the dark side facing out. This helped you to avoid taking several exposures on one piece of film. I'm definitely going to have to check out your channel in depth - there's an ocean of knowledge here. Well done! Thanks - Charlie

[@PaftDunk]

Thought I was going to bed at 1am, I guess not

[@lobsterbark]

Seven minutes ago, oh boy.

[@GameDesignerJDG]

Same, but midnight for me.

[@WanJae42]

4:33am. Why not? Everything's closed.

[@mikem5043]

Used to have a b&w darkroom in my parents garage when I was in high school. Got some pics with a 4 x 5 view camera as well. You sure brought back some memories...

[@Tuxfanturnip]

Problem: film is not held securely against the middle of the slide My thought: put a glass cover over it Applied Science: put a vacuum behind it

[@austindoud273]

Honestly it should be ground glass on both sides

[@linecraftman3907]

@@austindoud273 ground glass will introduce distortions

[@skunkjobb]

@@austindoud273 Ground glass on the front side of the film doesn't sound so good.

[@kricketflyd111]

engineering : put a field around it.

[@comeradecoyote]

The reason you don’t put glass on both sides is because you will get newton’s rings which will alter the resultant image. Additionally glass has a different coefficient of reflection/refraction than air and could lead to slight distortions.

[@cs-xy5fr]

You have one of the coolest channels on KZbin. Thank you for sharing all these projects!

[@jonathanlarson32]

When you are exposing the slide wouldn't it be best to blacken the insides of the tube to improve the point source for the light?

[@numlock6019]

good point!

[@GregorShapiro]

The filament is several orders of magnitude brighter than the white of the tube so the diffuse illumination would amount to a few seconds of filament exposure. It is measurable but not really necessary especialöly with the good contact between the emulsion of the film and the photoresist on the slide.

[@stargazer7644]

Gregor Shapiro in other words, yes.

[@dolantremp]

I never understand anything you're doing and yet I am completely enthralled by every single one of your videos

[@DrakkarCalethiel]

7:10AM, moring already begins with amazing content! The moment you mentioned the microscope slide and another channel, I immediately thought about the thought emporium and his "head cheese" project. :D

[@Masoudy91]

You are a digital archives of human technology. I salute you, sir.

[@maxk4324]

Me: Sends taxes on 1/100 scale check IRS Employee: Opens cabinet and retrieves microscope next to a code breaking manual and a box labeled "mustard cleaning kits" (for those Johny O fans out there)

[@sleeptyper]

IRS Employee writes a letter: Dear Ben, we asked you already two years ago to not send your taxes on a media that requires a SEM to read. Our budget cuts are getting worse year by year and currently nearest SEM is at the university, which at current traffic ... err, nevermind.

[@johncrowerdoe5527]

1/100 scale would be fairly close to their traditional microfiche / microfilm archiving of old documents. Just slapping it into the viewing station should make it readable with strong glasses.

[@simoncoelho8831]

Would be awesome if you did a video on how to make a makeshift ventilator system! Hospitals are running out, so having a guide on how to go about making household objects into a last resort ventilator would be really really helpful.

[@dhoyda]

"I have no interest in this at all" 30 minutes later "whoa, that is absolutely amazing!"

[@dathaniel9403]

I actually found your channel because of Huygens Optics. What an amazing wealth of knowledge that man has.

[@kevinmartin7760]

Your resist exposure would be even more point-source if the inside of the collimating tube were black.

[@quackerzdb]

This is the highest quality youtube channel I know of. Thank you Ben, you make this stuff so interesting and you always answer every question I have about the process as you go. The details surrounding the film holders were very engaging.

[@noahtaylor7632]

Ben: “this film has a beer belly” Me: “make a little vacuum plate” Ben: “I made a little vacuum plate” Me: ... whoa

[@rickharriss]

1. Many year ago now i worked for a company that made early circuit design equipment. The output was to a large photo plotter that transferred the electronic image to a photo plate. Our set up resolution was 3 microns so two dots could be repeated 3 microns apart. As an experiment I devised a system that took a small, 1 inch diag, CRT and drew the image on it line by line. This was passed through a 35 mm camera lense but in reverse so the end image was about 10x smaller and projected onto a section of photographic film on a drum. the drum was incrementally turned for each new line and eventually the image built up. We wrote software to break the image up into sections and lines and display them one at a time. We were able to get very repeatable and respectable results from our system compared to the commercial results from a much cheaper and simpler system. 2. You could mount your digital camera to look at the ground glass screen, or even remove the ground glass and set it at the focus plane to get a clearer view of the focus point. 3. Really appreciate you channel. thanks

[@RichardKinch]

Cool camera! But: The lens should be imaging spot sizes on the order of (in microns at the image plane) 1.3 times the f/number of the lens. That's going to be much better than the film grain size, which is on the order of dozens of microns. Optics is always governed by a weakest-link principle. So you really can't improve the weakest link, which is the film grain in this case. The f/number of a lens wholly determines the spatial resolution of the lens images, but the film grain is not "impedance matched", rather like parallel resistors 1/r = 1/r1 + 1/r2. See my optics discussion at www.truetex.com/raspberrypi.htm regarding "Specified, theoretical, and actual resolution".

[@recklessroges]

You sound like you know a lot about optics. I look forward to reading your optics discussion.

[@Nobody-Nowhere]

You can improve the film grain, by using ortho film like he is using. And saying that the F number alone determines the resolution of the lens, in theory land. Not in reality. Like he is using an old single coated Symmar. More modern multi coating alone would improve the resolution. Also simply filtering the light, as you only need single wavelength to do this type of stuff. There are lenses available for this exact job. Lenses are also designed to work on different magnifications, different wavelengths etc. Its just not some simple calculation that F number defines everything.

[@Mythricia1988]

I always try to tell people about this when I see comments online about how photographic film has "infinite" resolution... But nobody ever seems to believe me when I talk about film grain size :\

[@Nobody-Nowhere]

@@Mythricia1988 On ortho, its basically true. Ortho films have higher resolution than any lens can deliver. Even something like tmax 100, resolves more than any realistic lens can do. On 35mm, your absolute max lens resolution in real world would be something like 200lp/mm (still something you really cant find, maybe sigma art 40/1.4 could do it). And tmax 100 resolves 160lp/mm on normal pictorial contrasts. And on medium format, max lens resolutions are around 120lp/mm and on 4x5" they drop down to around 80lp/mm, at 8x10" you can hope to get 50lp/mm from a lens. And these are the absolute best lenses you can find, and only center resolutions. So film grain definitely is not the limiting factor. Especially if we are talking about technical ortho type films.

[@FROSTBURG2]

@@Nobody-Nowhere Resolution depends also on the contrast of the subject. With high contrast test charts Zeiss got 550 lp/mm from the middle of a Biogon 25/2.8 ZM on microfilm stock.

[@cs-za]

Ben, every video you make I am just blown away by your knowledge and ingenuity!

[@TheWilldrick]

13:34 The other kind of film you refer to, the one you need to manipulate in total darkness: is it IR sensitive? The comment of you seeing better on the viewinder just made me think, you could use some IR LEDs and a night vision camera to load the film with ease :D

[@creepyloner1979]

panchromatic b&w (and colour) film usually isn't ir sensitive, and plenty of people use ir cameras to develop it.

[@stargazer7644]

It really isn’t hard to learn to do this stuff by feel in the dark. You learn to remove film from 35mm canisters, and load it onto reels in the dark, and assemble the reels into light tight developing cans. Just takes practice. I used to remove film from all kinds of broken cameras for people in a dark bag with sleeves all the time.

[@RraMakutsi]

2 bits of advice that could improve your results: First, the "handle" end of the dark slide should have a dark and a light side... that way you can insert it one way for unexposed film, and insert the other way for exposed film (helps to reduce confusion when working with multiple film holders). Second tip, four words... Flat. Field. Macro. Lens. That will give you the best focus/clarity when attempting to photographically reproduce 2-dimensional objects. Thanks for the great content!

[@ken830]

You have a Radio Flyer Tesla Model S project car!?!? I'm interested in a video about whatever the heck you're doing with that!

[@austindoud273]

Hey I was going to make this comment

[@cleitonfelipe2092]

You have the best science channel on KZbin

[@kaunomedis7926]

I have to use mercury street lamp without protective glass. Lots of UV in one spot.

[@wonderwulf]

I think that is something like what he has here!

[@paulmaydaynight9925]

wouldnt the tried and trusted generic DIY hydrogen/oxygen theater "lime light" lamp give a far fuller and brighter plate coverage here and cheaper/better than todays hightec over priced,under speced versions

[@teresashinkansen9402]

@@paulmaydaynight9925 A lime light only reaches at most 2800 C° but usually lower temperature, not that different from using an overvolted halogen lamp and much less convenient, as a black body radiator at such temperature the UV output is very low. With an arc lamp you not only have the benefit of a much higher black body temperature but also in the case of medium pressure arc lamps a significant output comes from the spectral lines of mercury and other elements added. Also street lamps are quite cheap and last for many hundred hours as a powerful UV source, sadly they are being phased out, so time to stock up!

[@jimzielinski946]

All great comments. I'd like to add that certainly making a vacuum holder was ideal though there were some old tricks that photographers used. One trick was to use semi sticky glue that came in what looked like fat "chapstick" like tubes. Using plastic gloves to avoid leaving fingerprints, you could then press the center down to even it out. There was a company that briefly sold "sticky plastic" sheets for the same purpose. Your tools and techniquewith large format photography are really bringing back memories! Great work.

[@among-us-99999]

Can Piezo-Actuators be used for CNC stuff on a very, very small scale?

[@marklangridge2734]

What amazes me is that i have done many of these things in the lab, using much more sophisticated equipment, and not really gotten any better results. Very nice bit of work!

[@lorenzopale]

"Intel doesn't have a whole lot to worry about ... just yet."

[@legendarysideburns2213]

Honey I Shrunk the Tax Form

[@AMTunLimited]

Fun fact: there are 35mm "panoramic' cameras that take pictures two "spaces" wide. I haven't looked at the measurements but by eye it looks like that would be exactly one slide in area!

[@jimsvideos7201]

ISO 2! o.O