There have been reports around Zurich of people seeing a man standing motionless for minutes besides a big wooden box, only to then fumble inside this box for some more minutes for no apparent reason...
... well, that was just me, taking pictures with my homemade 40x50cm camera on color paper. You think this sounds crazy? Well it maybe is - let me tell you the story of "Big Tuna":
In the past I shot a lot of black and white direct positive paper and the idea of creating unique pictures directly in camera without having to develop negatives and enlarge them fascinates me. One day I stumbled over a video from Joe Van Cleave and Ethan Moses (check them out, they are awesome, links below) where they made direct positive paper pictures but in color! With a simple trick they did a reversal development and created direct positive images with regular color RA-4 paper. I was immediately hooked, that's what I wanted to do, too!
Since color paper is only available in paper and not sheetfilm sizes, I started to test some 13x18 paper with my old 5x7" camera first. I had two main questions in creating decent pictures:
- What is the exact ISO speed of the paper?
- What is the correct color balance of the paper?
I tried a lot of different filters to get the colors right. Without filters, the pictures were just tones of cyan. I tried everything, from special tungsten filters, black and white filters to multigrade filters for black and white paper. Surprisingly I got the best results with Ilford multigrade filers, that are normally used for black and white enlargements. I stacked the Filters 00, 0 and 1.5 together. After all my tests I found out, that Joe and Ethan came to exactly the same solution. I optimized my filters with the 00 and 1.5 from a very old multigrade set I found. The filters were already a bit faded and the results got even better. Unfortunately I have not yet found a way to record the color green, it's always orange. ISO is probably around 8, but with the filters in place, I got ISO 3.
After having a feel for the paper, I started thinking about a way to get bigger pictures - a lot bigger. The largest paper I could process in my own darkroom was 40x50cm (16x20 Inch), so i settled for this paper size. Unfortunately there are no affordable cameras around for this size, so I had to built it myself...
I consider myself a decent craftsman, but building a proper large format camera with bellows and filmholders was definitely out of my league... So I remembered the saying that "the camera is just a black box" and build exactly that. Actually, I build two boxes that fit snuggly inside each other in order to focus the Camera and refill it with paper. So here it is:
Since it vaguely looks like a fish with fins, I called it "Big Tuna" (the office fans will also like the reference :-))
The Lens: I found this lens on Ebay, it's a 600mm f10 Lomo lens without a shutter. I think they used it for technical reproduction. It was only 200 Bucks and the image circle is huge!
Composing the image: Next to the lens I drilled a hole to look inside the camera. When the lens is uncovered, you can easily see your image projected onto the white painted backwall of the camera.
Focusing: In the back of the camera, I installed another hole that I outfitted with an old Rolleiflex groundglass I had. With this, I can achieve very precise Focus by sliding the boxes into each other with some handles I attached.
Handling the Paper: I attached two sleeves from an old changing bag. With those, I can load paper inside the camera.
Inside the camera lays just a box of paper (actually two, for fresh and exposed paper). I take out one sheet, hang it in the back with some magnets, take the picture and then put it back into the box.
Taking the Image: The necessary filters can be lowered in front of the lens. And the shutter is just a cap I made out of leather and cardboard. Since I meter for ISO 3 at f90, I always get exposure times in seconds which is easy to do with this cap shutter.
Developing the Paper: The trick is pretty simple. Color paper has different layers with differently sensitized and dyed silver grains. When the special color developer (RA4 process) develops the silver, it also develops the pigment in the dyed silver. This brings color into the picture. Regular paper developer cannot do this - and that is the key to the reversal process. So here is the process to develop color paper directly into positive images:
Develop the paper in regular black and white developer. All the exposed silver will be developed, but NOT the color pigments. This will result in a black and white negative image (this must be done in complete darkness).
Stop the development. I just wash it multiple times with water in complete darkness. Using a stop bath is risky because it can damage the chemistry for the next steps.
Turn on the light: This will fully expose all the remaining silver that hasn't been developed. Since we only developed the negative image, the now exposed silver will be the invert of this - the positive.
Regular color development: now you can just develop the paper regularly in RA4 chemistry in daylight, this step is absolutely awesome:
The Results: Since there was a nation wide lockdown, I could just take photos in my close neighbourhood, but I like them a lot so far!
I hope this inspired some of you to realize crazy ideas and be creative! And if somebody has some cool ideas for this camera, I'm in!