Sharper pinhole image,Part Two

[kevin klein]

I finaly did some more "try it and see" tests and found out a couple of things.

The pinhoe used in conjunction with the camera lens is best.

The smaller the pinhole the less sharp the image becomes.

My thaught was that a smaller pinhole gives a sharper image but not so. The camera being used is a 4x5 and the pinhole is .018 or .020 aprox, brass shim stock blackened with a solution stained glass workers use to patina the leadding.

The film being used is Kodak T max 400, exposures are quite fast, 1/2 -1 sec in sun, 10 sec in shade. when I get someone to post the pictures you can see some examples. (I am computer illitteriate...)

 

[Dave Wooten]

Kevin, the pin hole size and sharpness is also related to focal length. There are optimal pin sizes for a particular focal length.

 

[bobwysiwyg]

I remember someone posting a link to this, so I Googled it again..

http://www.pinhole.cz/en/pinholedesigner/

 

[Tom Hoskinson]

Some Pinhole Design Trade-offs

I remember someone posting a link to this, so I Googled it again..

http://www.pinhole.cz/en/pinholedesigner/

And, in general, the smaller the pinhole, the greater the diffraction effect.

Pinhole design involves several trade-offs. Focal Length; pinhole size; light frequency; diffraction; size of the minimum acceptable size circle of confusion; are the ones I can remember off the top of my head.