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Thread: I'm new hello to all

  1. #1

    I'm new hello to all

    Hi Everyone. First time on forum although I have been reading/watching f295 for a while; really enjoyed the info and the banter.
    So; here we go. Made my first pinhole some weeks ago, usual OXO tin job, worked quite well all things considered, well, the second one did! Never realised just how much fun pinholes are, and, you donít need £????? of camera and lens to take good photos either. Well: what with world pinhole day looming up I thought Iíd make a more sophisticated, portable pinhole by using one of my Zorki bodyís. Now; I have said body and brass shim and Lord Rayleigh informs me that-----with a focal length of 28.8mm I need a pinhole dia of 0.239. Would you guys agree, and am I okay using my Zorki or am I making things hard for myself with such a small focal length. Learning all the way.

    Thanks one and all.

    Thickasaplank

  2. #2

    I'm new hello to all

    welcome, thick! i think that shorter focal lengths are more interesting in most circumstances- go for it!

    my calculator advises a 0.197 pinhole, so i would probably start there, and enlarge if needed. should be about f146. good luck.

  3. #3

    I'm new hello to all

    Lord Rayleigh's calculations may suit mathematicians, but seem to give a slightly oversized pinhole. PinholeDesigner, with a user constant of 1.5 determined by much experimentation, gives a diameter of .189mm at f/152. As pinholes go, that agrees very closely with Steven's figure. My user constant is optimized for best on-axis sharpness. Many pinholers may sacrifice some of this for better off-axis sharpness by using a slightly larger hole. Pinhole cameras work better with short focal lengths than with long. Increasing film size improves image quality somewhat.

  4. #4

    I'm new hello to all

    I'd go with Jim and Steven on this one -- I get .21 mm with the calculation I usually use, but there's growing evidence that most theoretical work contains assumptions that result in a hole too large for best real world sharpness. Going 10% under seems to work well, which would put you in Steven and Jim's region around .19 mm, or about .008". If you can make a very round hole with the thinnest possible edge at that size, you ought to get about all the resolution 35 mm pinhole can deliver, short of building a camera from scratch with very short projection distance (say, 10 mm).

  5. #5

    I'm new hello to all

    I can see this rapidly degenerating into another one of those discussions where a bunch of guys who should know better [!] get hung up on size... don't worry, size isn't everything!!!

    It seems your main thrust was regarding the use of a 35mm camera body, to which my response is: "go for it". You won't get the image quality of a larger format but it'll be cheap and convenient and you can run off heaps more photos in any given time and budget than just about any other rig. So, let the experimenting begin !!!!

    always nice to see a new member join the forum...

  6. #6

    I'm new hello to all

    Hi guys. Thanks for the welcome and the help. Interesting stuff this pinhole experience. Glad to know my Zorki will suffice until I gain enough experience to build a pinhole from scratch. So: if Lord Rayleigh is out what calculators do you guys use then, or is it a case of experience plus a little math. Any tips on the actual making of the pin hole. Like what you use to make the hole. And should I black out (paint) the shim when finished or does it not matter?


    All the best
    B.

  7. #7
    500+ Posts toniox's Avatar
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    I'm new hello to all

    Hi thickasaplank, i think you could make a hole without the math, just make a hole with a little pin and test it with your zorki.

  8. #8

    I'm new hello to all

    Hi,

    Personally I have a set of titanium coated microdrill although my set starts at 0.3 mm.

    constantine

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