Filmwasters
Which Board? => Main Forum => Topic started by: xander1027 on June 14, 2006, 10:48:28 PM
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today the pinhole camera i bought online came and i just have some questions you could possible help me with. the camera came with 3 different pinhole sizes .2mm , .3mm and .4mm. the pinholes came with a card telling you the f stop well it reads across .2mm pinhole diameter, 20mm focal length, 100 f number, and 20 for f22 and then there is a picture of the pinhole this is he smallest of the three. but what i dont get is it says the .2mm pinhole has f100 and the .4mm has f200. the picture for the .4mm pinhole has the biggest hole. i would think it would be the .2mm with the smaller f stop. is this the way it is with pinholes or is there a misprint. thanks
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Suggest you ask ths on f295.com or just look at the pinhole calculators on that site which will answer all your questions for you!
Hope this helps, Carl
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If the focal length stays the same, then the smaller pinhole has the smaller fstop, you are right. But, if the focal length is 20mm, then 20/0.4mm= f50. I think ;)
Anyway, I use this calculator.
http://www.johndesq.com/dpr/calcdocprintout.htm
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If you don't want an on-line calculator, www.pinhole.cz has an excellent version for Windows.
And if you feel like tinkering around, they also have the world's cheapest camera on the site... a Do-It-Yourself kind of thing.