Yep, this is what I do. But then I just measure how many mm in 2cm, and do just what Bert said.
Originally Posted by NormanV
And if you are aiming at a particular diameter, you need to make it slightly too small and then slowly expand the pinhole until it's just right.
Honestly, I've only done this a few times. Usually I just make several pinholes and hold them next to a ruler with mm markings, look through a hand lens, and pick one that's close and looks clean. You might find different pinholes do have different character. Occasionally there will be one that makes particularly nice pictures, and it's not always just about sharpness... sometimes there is just a "certain something" and it is hard to say what it is.
I've swapped out the pinhole in my instant film camera several times. The first few looked perfectly round and clean and the right size, but were unsatisfying. The one that is in it right now was a little too small and close but not perfectly round, but it's my favorite so far. I used paper negatives in it to test the different pinholes quickly without wasting film. You could try that if you want. Quick and easy.
( Okay, actually now that I think about it, that's not totally true. I did use paper negatives and picked the best, and it looked really good, but ended up swapping it again after that... the color instant film pictures were not as good as the b/w paper. That could have been because the paper is not sensitive to the same range of wavelengths, or just something subjective about instant color film, I don't know. So I'm not sure the paper negative advice is good after all. )
Last edited by NedL; 10-31-2013 at 02:09 AM. Click to view previous post history.
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