Experiments in Digital Pinhole Photography

In May of last year, I was talking to a friend about camera obscura and pinhole cameras and I wondered if I could turn my Nikon D200 digital SLR into a digital pinhole camera.

My first attempt at creating a pinhole camera was to tape a piece of cardboard with a pinhole on top of the lens. I also constructed a foot-long tube, wrapped in tinfoil and taped it to the camera body. My thinking was that I could construct my own pinhole zoom lens. The problem was, I had to go manual focus because in auto the camera wanted to focus on the pinhole. Anyway, I got a few interesting photos but it just seemed like I was just shooting through a hole -- not really a pinhole camera. 

Pinhole on top of a 105mm camera lens.

28cm long pinhole lens on 250mm camera lens

I gave up on constructing zoom lenses and took the camera lens right off. For my next attempt I just taped a piece of cardboard over the lens mount and poked a hole in it. The shots I got from this setup were quite neat. It was a bright day but the pinhole was large enough that I was shooting at 1/15s. This was faster than I had expected, but I wasn't sure how to make the hole smaller. You can also get an interesting effect from two pinholes as in the second photo below. The second is off center so it provides an offset image on top of the other.

Single pinhole in cardboard. 1/15s.

Two pinholes in cardboard. 1/15s.

Single pinhole, some very nice vignetting.

The detail in the three shots above was about as much as I could get with a pinhole in cardboard. There is much to be concerned about regarding the pinhole size. Notably, the smaller the pinhole the more focused the image should be. The hole should also be perfectly round, which is very hard to do with a pin and hammer. The cardboard I used was not ideal, I now know. At the time I was concerned that paper fibres may have obstructed the hole. Tinfoil may be a good material but it is liable to warp if not sufficiently taped.

That's where I left it a year ago and hadn't thought about it much since then. However, just last week the subject came up between myself and another photographer and it got me thinking about trying again.

So, I got down to business and constructed a new lens, the PL3 ($780, est.) out of a tea can with a metal bottom. After mounting the camera using the PM3 lens mount (included), I found the initial photos to be very fuzzy with too much internal reflections. The inside of the can had a silver metal foil so I had to cover this with a black construction paper. I also used tinfoil around the base to ensure that there was no light leakage at all.

PL3 lens with the PM1 lens mount.

PL3 lens showing the PM3 lens mount and the special light dampening black insert.

Another problem with these lenses, in general, is the increased amount of dirt on the internal sensor, see the picture below. It took an hour to clean it off since the camera battery was below half charged. The camera will not let you open the shutter for cleaning if there is a chance the battery will run out while you're wiping the sensor. Since the pinhole aperture is really small, it tends to enhance any dirt on the camera sensor.

Internal reflections due to silver lining of the tube.
Also note the large hair on the sensor that wasn't there before.

Anyway, once the lens was mounted and tested I set out to Clover Point to take some pictures.

Trial Island

Gonzales, Victoria

Ross Bay Trees

Two dogs in tall grass.

I was hoping for more focus but I was still pleased with what I got. There is a real impressionistic feel about these photos. You kind of have to change how you see the world you're going to photograph. Instead of looking at details you have to look at shapes and color.

I still can't ignore the focus thing. I was hoping for more. So, the following day I constructed another lens. I wanted something shorter so I could take wider photos. This time I went back to cardboard but with a tinfoil end and built the more economical PL4 ($480 est.) with the PM2 mount (included). One (of many) disadvantages was the use of the stronger mounting tape which can leave a sticky residue on the camera body.

This time I took a trip to Saxe Pointe and Macauley Point parks in beautiful Esquimalt. I was definitely getting better focus but it was still a little fuzzy giving the pictures a painterly effect. There's also a definite color cast to the pictures. They almost look like they were taken in the 1940's or 1950's.

Beacon and sailboat from Saxe Point.

Houses from Macauley Point.

It may be possible to get better focus by building the better pinhole lens. As it stands a better mount would be preferable so that a quick change would be possible instead of all the taping required. There's a lot more experimentation to be done but I'm happy with some of the photos I was able to get.