This is a 34 hour print, and will be done in two batches. When it’s finished, it will be a pinhole camera. I’m using a 0.2mm pinhole, so I will need to recalculate the f/stop, as the maker intended 0.23mm, but I wanted to go with a commercially made, laser cut pinhole. I picked it from ebay from this seller: https://www.ebay.com/usr/fireseller66
In the case of using a smaller aperture, it’s a 29mm focal length, and a .2mm aperture. Which works out to f/145.
Using the Mr.Pinhole Calculator: http://www.mrpinhole.com/calcpinh.php
We get this:
This a view of the camera when completed, I’ll be using a wood veneer to produce a similar effect.
Overall, I’m excited to take this guy for a spin, and will report back!
A Russian pinhole photographer named Anton Savitskiy was making some really cool images, that I saw in some of the pinhole groups on Facebook. The images were anamorphic, and produced a sort of distortion that I hadn’t seen before. I have tried to re-verse engineer how some of these “upside down” distortions work, with curved film planes and the like, but without success. Here’s an example of his images:
I wanted to make a camera to try and get a similar effect.
I spoke with him at length in the comments, and tried to get an idea for how his camera was made. This distortion is caused because the angle of the camera to the subject is such that the round pinhole is in effect an ellipse. The film plan is also curved along a convex curve. These two things produced the effect you see above.
I couldn’t quite understand the specifics of his process, so it was time for some experimentation.
I measured from the center of the photomaterial, to the pinhole, and came up with 85mm, and this is what I based my focal length on: result, 85mm. I measure the pinhole, a touch large, at .45mm. From this, I used the Mr. Pinhole calculator to determine my camera was f/190.
I may have made a mistake in my metering (probably relating to initial ISO, because my first two exposures were so far off they blew out my paper entirely. After two attempts, I began “guessing” at exposure times based on my previous experience with pinholes, and got a workable image… ish.
However, I noticed the exposure varied from top to bottom. In retrospect, this makes perfect sense, as the 5×7 photopaper is only 15 or so mm from the pinhole at the top, and 150ish from the bottom. I has used the middle as my average, but I hadn’t accounted for the front being so much shorter. I had mistakenly assumed I’d fall off towards the edges from the center, not a linear gradient from bottom to top.
So I cut the paper into thinner strips, and tested them at top, middle, bottom. This instinct is correct, and I’ll be much closer to proper exposure a second time around.
These were then underexposed once I found the “proper” position. I suspect my angle is too steep, and will need to come down a bit, as the angle of view was not a severe as I expected. I also might have used too large a cylinder, and may need to use a 16-oz drinking can. I will experiment further and report back.
My cyanotype chemicals arrived this week, and I’ve been printing some photos using a large ball of fusion gases that I have available for a large chunk of the day. The process is a fun one, everything from preparing the paper, and figuring out the proper exposures as clouds ruin my timing, etc.
Overall, I’m pleased with the process. I’ve found portraits to be a bit difficult, requiring two or three attempts to get the proper exposure, but here’s an example of a photo that came out well. I’m considering placing some of these in the shop, if there’s interest, please let me know.