This week, I’ve been dabbling in pinhole photography.
I was looking for something in a shoebox in the shed the other day and I found a bodycap for my EOS 50.
“Great,” I thought, “I can drill a hole in that!”
For some reason, I thought I’d have to put it on my film camera but it dawned on me pretty quickly that it would work just as well on the 20D. So I drilled a hole and tried various materials to poke the tiny pinhole into.
You need something dark, or light-tight, but easy to put a hole in. My first effort was just with a very small hole in the body cap itself. This had problems: the hole wasn’t round so everything was really fuzzy.
Then yesterday, I was sitting at work and thought if I ripped apart an old floppy disk, I could use the disk material itself. It’s pretty dark and, I thought, opaque. Turns out it’s not and while it didn’t really leak light, it just wasn’t very good.
So then I looked at my dismembered floppy again.
All the good how-to-make-a-pinhole guides tell you to go to a specialist store and buy a specialist kind of specialist copper sheeting to put a small hole in. “Bugger that,” I thought. I didn’t want to spend any excess money or have a bulk supply of copper sheeting when all I needed was a few 2 cm x 2 cm pieces.
Back to the floppy, I ripped off the metal bit and it turns out it’s a very pliable but solid piece of metal. It’s thick enough to be fairly sturdy but thin enough that it can be pricked without too much effort and even cut with scissors.
My first hole was a little big, so things were quite fuzzy. So I tried the other side of the disk, so to speak, and made a much more controlled effort at jabbing. I used a proper chart pin to do the jabbing. It has a nicely tapered and pretty round end, so once I made a much smaller hole in the next piece of metal, I twirled the pin a bit to even out the edges.
The results were much sharper images. Here’s a test shot of my phone and some mints under the light of my desk lamp.
This was a 30-second exposure.
While I’m impressed by how sharp this is, obviously there are some limitations on this combination of lens and camera.
Firstly, the sensor size lets down the whole enterprise. Because it’s so small, we’re only getting a section of what we’d be able to get on a full 35 mm or 120 frame. The 20D is an 8 mpx camera. This pinhole with the same focal length on a 120 negative, scanned to 8 mpx would give you a much sharper image because of the sensor size. The closer the pinhole to the sensor, the smaller the aperture needs to be (to get the sharpness you want), the longer the shutter speed you need.
To get a wider angle on this camera, you’d need some kind of funnel-shaped body cap with the pinhole at the tip. And even if you could rig one of those up, forgetting the fact that the mirror would hit it twice per exposure, you’d need a much smaller hole to get the same degree of sharpness.
The other limitation is the shutter speed of the camera. The 20D (and, I think, my EOS 50) has a max shutter speed of 30 seconds. If you had a smaller hole, you’d need more light, so short of spending a shitload on an electronic cable release, multiple exposures may be the only way to get the long exposures you’d need.
Next trip I take, I’ll probably run a film through the 50 and see how the wider frame works. I’m not about to rip apart my Holga to experiment with a full 120 frame. Watch this space. And I’ll post a few more test shots here.
