jose angel
31-Jan-2018, 12:04
Hi all,
I`m working on a project that will be performed with pinhole images. I have everything but the pinhole, just because I`m somewhat dumb and don`t know which aperture to choose. I`ll use my 8x10" film holders, the camera is a wooden one with a focal lenght near to 140mm.
I just need the pinhole, so after some search I found that the mounted ones from Edmund`s may be the best suited (thickness looks to be 0.001"). At first, I thought to settle on 0.5mm (according to the calculator the optimal focal length is 141mm) but the coverage is 271mm... a bit small (the diagonal of 8x10" format is 316mm, so I`d get some vignetting -actually light fall off-).
The other choice is a 0.6mm pinhole (optimal focal length is then 202mm, -I can modify the camera to hold it-), with a way larger coverage (388mm). Drawback to me is the narrower field of view (aprox. 75º with a FL of 202mm, vs 95º with a FL of 141mm).
So I wonder how much unpleasant the light fall off with the 141mm camera could be; a gradual softening in detail and light could be even interesting; but if the fall off is something like a sharp black border it could be actually ugly. If so, I maybe should go for the longer focal length.
What do you think? Any experience, or sample images? Thank you.
I`m working on a project that will be performed with pinhole images. I have everything but the pinhole, just because I`m somewhat dumb and don`t know which aperture to choose. I`ll use my 8x10" film holders, the camera is a wooden one with a focal lenght near to 140mm.
I just need the pinhole, so after some search I found that the mounted ones from Edmund`s may be the best suited (thickness looks to be 0.001"). At first, I thought to settle on 0.5mm (according to the calculator the optimal focal length is 141mm) but the coverage is 271mm... a bit small (the diagonal of 8x10" format is 316mm, so I`d get some vignetting -actually light fall off-).
The other choice is a 0.6mm pinhole (optimal focal length is then 202mm, -I can modify the camera to hold it-), with a way larger coverage (388mm). Drawback to me is the narrower field of view (aprox. 75º with a FL of 202mm, vs 95º with a FL of 141mm).
So I wonder how much unpleasant the light fall off with the 141mm camera could be; a gradual softening in detail and light could be even interesting; but if the fall off is something like a sharp black border it could be actually ugly. If so, I maybe should go for the longer focal length.
What do you think? Any experience, or sample images? Thank you.