Thoughts 01 Oct 2008 08:00 pm
Pinhole
I built myself a pinhole lens for my Nikon D70 out of some old stainless shim stock and a body cap.
I used the finest sewing needle I had, set a 1/2 x 1/2 piece of shim stock on a board and tapped the needle through with a small hammer.
This is my best effort so far.
Click on the image for a larger version. (1500×997)
The original size is 3008×2000 and when I pull it up on the monitor it’s so fuzzy it hurts my eyes.
–I processed this shot by using the clone tool in Photoshop remove the worst of the dust from the frame and then ran auto levels to clean up up the colors and contrast.
So far the problems I have run into with a digital pinhole are dust, dust, and more dust. A pinhole lens on a digital camera can find dust in a laboratory clean room. I even glued a uv filter over then cap when I was done and it still sucked in the dust.
Determining the pinhole size and shape is an ongoing experiment. And while I can buy pre-made pinhole caps or a set of 12 pinholes in various sizes, they are all micro-drilled and I’m not certain that will give me the image I want.
(The rule as I understand it is the smaller the hole the sharper the focus. But each hole diameter represents a give distance from lens to film(or ccd) running anywhere from 3.5mm to several inches.)
The Nikon body caps I have seen for sale seem to have a hole diameter of .0102 which should work out to about the same coverage as a 50mm lens on a full frame camera. This means that for a dx camera I should need a hole about .008+/-.
I think I may even buy some pre-drilled pinholes to play with but I intend to continue to experiment with my needle and hammer approach.
My first pinhole camera was an old Quaker Oats box with a home grown film holder for 120 film cut into 4 or 5 inch lengths and it worked well for what it was, but with my nifty neat and wonderful digital pinhole camera I can test my exposure without wasting a lot of film or even needing to know my f/stop.
If you go to Pinhole Resource they have quite a bit of information. They also have cameras, body caps and pinholes for sale.