Topic: Projecting in reverse

[jojonas~]

It seems like every summer I get a hankering for putting darkroom papers more or less light tight boxes and let the sun get to work on it.

This week I was out shopping and decided to take a peek in at the local flying tiger. Scored a cheap and simple phone projector with a nice and big focusing lens. I felt right away that it was big enough to put some small papers in there.
(I also scored some cyanotype papers they sold, gonna try them later)

Either way, after checking the focus and taping up the box a bit, I took it out and let it sit for 40 minutes with a photo paper inside. 20 min would probably been enough but it was my first time shooting through a mirror so I gave it a bit extra time.

Next shot I'll try inside, keeping the exposure shorter and develop the paper with caffenol.

[jojonas~]

oh, I redid the instructions when I was waiting for the exposure too

I'm thinking of drilling a hole in the top part to check focus/composition. that and maybe sort out a holder for the paper inside with a lid that I'd be able to pull back from the back side

[Francois]

That's like a big Polaroid in a way. The bonus part is that you get a correctly oriented image (left to right).
You should glue some wood strips on the inside corners, that would definitely take care of the light leaks.

[jojonas~]

That's like a big Polaroid in a way. The bonus part is that you get a correctly oriented image (left to right).
You should glue some wood strips on the inside corners, that would definitely take care of the light leaks.

good idea! I'd held up surprisingly well, sitting in the sun like that already though.

[Francois]

I must admit that cyanotype is probably the best emulsion for this considering how little sensitivity it has.

[jojonas~]

I haven't had much luck with cyanotypes in cameras. but I've seen other get it to work so I'm not giving up! I guess the lens swallows a lot of the UW light? though a simple one(?) lensed thing like this might give a better chance just because of there being less glass surfaces to go through

[Francois]

It depends a lot on the plastic used, the thickness and a bunch of other factors. You probably would have much better chance with a thin fresnel lens. Less material to go through means less chance of UV absorption.

But there is another possibility. Have you ever looked at the Wolcott Camera?
This one used a concave mirror to focus the light on a small plate. No lens required. You could probably make one using a large bathroom mirror and get pretty decent results.

[jojonas~]

huh, I was familiar with the wolcott but I hadn't thought about using one of those close up mirrors for it. could be interesting.. small pictures for a big camera though.

I quickly found some one had made plans and tested a laser cut version. I could try scaling that up to the mirrors we have here
https://www.guyjbrown.com/blog/wolcott-camera/