Awesome!

I was looking for this video as well, it turned out that I had to make it.

I was surprised that enough UV got through to make an exposure in a semi-reasonable amount of time. I’m not sure how much you’ll get out of modifying the lamp and colour wheel - I’d assume that a lot of the UV is getting absorbed by the optics… but if you have a spare projector, could be a fun experiment.

I‘ve done that to one of these casio uv purple laser excited units, Inremoved the green phosphor wheel but my results are quite unsharp…

Awesome! That’s a pretty decent exposure time.

@@gearheadchannel How big were your prints, or about how far was your projector from the wall you mounted the paper to? Seems like the closer the projector to the wall, the shorter the print? Like any other photo process, right?

I believe they were around 18” x 24”. Yes, the closer the projector, the smaller the print… and also shorter exposure time (inverse square law)

awesome!!! I'm experimenting myself. thanks

which projector did you use? short throw? dlp, what is lumens? when I use the distance calculater with a short throw to print small you need to be about 7 inches to print 16" wide, with a 1024x768 resolution, what res is your projector? thanks, and are you seeing pixels at smaller sizes?

It ended up working far better than anticipated.

Sounds like an IR hot mirror to prevent the light source from melting the slide… on account of it being a thick piece of glass, it’s also a UV filter.

Thanks. It’s just straight black and white. I think tinting the image would most likely reduce contrast and increase exposure times. The thing is, most of the UV from the lamp gets absorbed by the projector’s optical elements to - so, further filtering the light probably won’t do you any favours.

ahh cheers that makes sense on another note, i have a spare projector lying around. I wonder if i could take some of those elements out to get a better picture, any ideas? i'll keep you updated @@gearheadchannel

The optical elements are there to create the image, so you can’t really remove any of them and still have an image. The problem is that the optics are made from glass - and glass is nearly opaque to UV. If your projector is DLP, taking off the colour wheel might be an experiment worth trying. (If you don’t mind destroying a projector) The lamp itself has a filter, but that is to block IR, so I don’t recommended removing that as it’s there to essentially prevent melting the important bits.

Thanks 😊 - this was done using the projector as is. DLP and LCD projectors use halogen bulbs that throw a lot of UV light… although it does go through glass optics, which absorb a lot of it on the way out. You need a pretty bright projector and a fair amount of time to get a print.

I never thought of that… I seriously think you might be on to something.

I tried the old school opaque projector approach but got zero results. Apparently my 25 minute exposure time wasn't anywhere close to what was needed. I seems that, even with a digital projector, you need an exposure time that exceeds 2 hours to see anything happen. I've been racking my brain about how to get strong uv light to project from that primitive little bulb inside. Anyone with an answer out there please save us!!!

Thanks. Yes it was.

@@gearheadchannel Thank you! I looked through the comments after I posted and got most of my answers from you. If I were to use a t-shirt instead of a canvas would it work the same way?

@IssaRajabi you should be able to make a cyanotype print on a T-shirt. There are probably a few guides on KZfaq. :)

Yeah, I think any projector that uses a relatively bright conventional lamp should kick out enough UV to make a print.

You're welcome. :) I'm not too sure if an LED projector emits enough UV to expose cyanotype, although it might be worth a try.

@@gearheadchannel Muchas gràcias!! Si pruebas avisa. 😉 si puedo empezaré a probar yo también.

@@gearheadchannel Una pregunta tonta, lo que proyectas es un negativo no?

@@perepascualsal correct

You’re welcome. :) You are going to need an older projector that uses a conventional lamp… the brighter the better. At least 1000 lumens, preferably more. Keep an eye out at thrift shops, pawn shops, and Facebook marketplace. Stick to well-known brands like NEC or InFocus… you should be able to find stuff from 10+ years ago REALLY cheap.

Epson and BenQ are two other brands to look out for.

Thank you!!!!!

Thanks. I feel like Wally Wikipedia might be a reoccurring character. UV art projector could work, but you might need a pretty powerful lamp… just make sure you don’t burn your house down in the process ;)

@@gearheadchannel I use low heat UV bulbs, but I'm expecting there's going to be extensive trial and error before I, you know: give up in disgust. Still, cyanotypes are cheap to make. It's about perseverance and taking notes. If you've ever eaten off a white plate, it's because of perseverance. Porcelain, white ceramics, were an Asian invention and the formula was unknown in the West. White pottery and glazes didn't exist in Europe. In the 1700s, Josiah Wedgwood thought he could figure it out. He made one glaze after another, taking notes every step of the way. His first dozen experimental glazes weren't white. Neither were the next fifty. Or the next hundred, two hundred, three hundred, and so on. He kept making glazes, firing them in a kiln, failing, and taking notes. In the 1760s, he finally created the white glaze he was after. He noted it as his 411th try. So, hey!, if I follow in his footsteps, there's a good chance I'll have *my* breakthrough by the time Bernie Sanders finally becomes president - at age 149! Maybe I should set my sights lower and try something easier, like the teleportation of matter or time travel. Decisions, decisions! 🐧

Can’t hit a home run without swinging for the fences.

@@TheStockwell Have you tried? Any updates?

@@1989FFA Yes I am also curious! :)

Theoretically it sounds plausible. Practically, it might be far easier said than done.

@@gearheadchannel challenge accepted

Smart UF55 pulled from an interactive white board

@@gearheadchannel thanks !

No problem. I used a Smart SBP-15 short throw projector that was pulled from an old interactive touch table. It’s an 800x600 pixel DLP with a conventional lamp rated at 2000 lumens of brightness.

@@gearheadchannel great questions!! I was wondering the same thing. One more question: I want to project on cotton fabric. do you have any suggestions as I experiment with this? take care

I haven’t tried fabric yet myself.

@@gearheadchannel thanks for response. my projector is on the way and I'm ordering cyanotype today. I've done cyanotypes on water color paper in grad school and it was fun! I'll let you know how it goes with fabrics. Peace bro.

Awesome. Let me know how it goes… especially when it comes to applying the Cyanotype emulsion to the fabric.

LED likely doesn’t throw enough UV to work with Cyanotype. I believe salt printing is sensitive to visible light, so that would probably work.

That’s a lot of questions with pretty complex answers. Basically… LCD or DLP refers to the method the projector uses to create the image, and ultimately isn’t too relevant in this case. The type of light source the projector is using will be more important. Older projectors (LCD and DLP) use conventional lamps which throw more UV than newer LED or “hybrid” light sources… in short, an older projector with a bright lamp will render the best results. A cheap low-power projector with an LED light source probably won’t work.

ok thanks, not easy to find old projector that will work well for that ! I'll try to find