John Fontana
1-Dec-2005, 10:54
I have a tophat extender which I have attached to my 210mm lens so that I can use the lens on my Ebony SW45.
I have looked through Stroebel's book but cannot find an answer to my query, which is:
What effect does increasing the image (film to lens) distance have, optically. Does it artificially alter the focal length of the lens, angle of view, coverage, depth of field etc etc? I am merely curious as to whether different compensatory exposure adjustments have to be made in the event of using the lens at long bellows extensions, or indeed in any other situations. Or is the difference too negligible to worry about
A query from one not steeped in the laws of optics!
John Fontana
I have looked through Stroebel's book but cannot find an answer to my query, which is:
What effect does increasing the image (film to lens) distance have, optically. Does it artificially alter the focal length of the lens, angle of view, coverage, depth of field etc etc? I am merely curious as to whether different compensatory exposure adjustments have to be made in the event of using the lens at long bellows extensions, or indeed in any other situations. Or is the difference too negligible to worry about
A query from one not steeped in the laws of optics!
John Fontana