View Full Version : pinhole contact printer

09-02-2006, 11:43 AM
I had been threatening to make a contact printer that was all daylight no electricity needed for some time now. It finally all came together.

The first things you need to know are:

a little about pinhole photography.
how to deal with paper exposure.
how to make some kind of back for the printer to hold standard film holders

So I had to rip the lens from one of my remanufactured cameras. I decided that it was a good time to finally make the printer. I made a pinhole lens with a 1/16 inch hole. To large for a camera but I thought it might work

after you get those things simi mastered your ready to go.

You just take your standard film holder and insert a piece of enlarging paper into the holder. Then you insert your negative over it. I used the next size up paper but I believe you could use the same size paper and negative. That is my next test.

So then you take the printer to a place with a consistant light source. I took mine along with a cup of coffee to the front porch. I pointed my light meter up and read the light. Since I have been shooting some paper negatives I knew that the ceiling of the porch is what I now call a dead light source. With a dead light source the asa/iso of the paper is 2. I had estimated just by looking that the aperture was f64. So I got a time of 2 minutes. I pulled the darkslide and left the camera sitting in a chair for the two minutes then replaced the dark slide.

I loaded the paper into a daylight tank and processed it for the max time I use for paper negs.

I was a little shocked to find that I had a print. There were two things wrong with it. The roof of the porch was clearly evident and the print was too light. I decided that the print was 2 stops under exposed so I redid the shot with a ten minute exposure. I added the extra 1/4 stop because I put a piece of frosted plastic over the pinhole opening. It was there to defuse the light and kill outside image.

so how did it look, here see for yourself. Attached files http://f295.f295.org/uploads/printertest_324.jpg (http://f295.f295.org/uploads/printertest_324.jpg)

09-02-2006, 05:56 PM
I built a 4x5 without using a camera frame. Just a big wooden box with a hole in one end and a film holder on the other. I test drove it a few minutes ago and it works just like the first one. I'm impressed. I might make the hole a little smaller in the new one. It seems to be about f 11 that will be a little quick if I use it in direct sunlight.

I would like at least f 22 i think.

09-22-2006, 11:17 AM
I was messin with my pinhole printer and found that a. I could do smaller sizes of film in the hollowed out 4x5 negative holder. All I had to do was to make a little negative and paper holder. I had already cut a bit of plexi to hold them flat. So not any size up to 8x10 can be contact printed.

then I decided that the printer needed a light source that I could use if I wanted a more predicatable situation. I went with an aquarium light I picked up at good will for a couple of bucks... change it to 60 watts.

the pinhole was too big it burned up the paper. So I drilled a couple of smaller diaphrams from coke bottle caps. those just sit over the original one.. So now I have a thick negative diaphram... the original is good for that. A normal one I can add and a thin negative diaphram. then by varing the time slightly I have really good control.

Why not just use a normal contact printer you ask.

Well this can all be done in daylight and useing a changing back to load and unload the hollowed out film holder. I develop them one at a time in a daylight tank so I'm totally portable. As noted in the original post I have a printer I can use in the sunlight or now with a bulb. Cool little thing indeed.