Hi all,
I'm new to LF and doing some sums ...
I take the data available for the 80mm Super Symmar and find this ...
It has an image circle (@ f22) of 212mm at which point the lens will be 80mm from the film. The lens has a stated field of view of 105 degrees. Simple geometry indicates the useable data on the 'input' side of the lens (the side where the subject is !) is in the same 'angle of view' as the 'output' side of the lens. Both being at 105 degrees.
Is it possible for a lens to have a 105 degree 'input' side and say an 80 degree 'output' side ?
This would mean a 150mm lens might have a image circle of 212mm and a field of view of 105 degrees yet also have a focus distance of say 120mm ... (YES! - I can fit the thing on a camera !) [I also get a little worried by the light striking my film at such an oblique angle ...]
Does anyone know of such technology ? I have put numerous lens data through my spreadsheet and they're all looking the same in that the angle of view on one side of the lens is the same angle of view on the other side. The final element on my 35mm 17mm lens is no closer to the film plane than the final element of my 200mm lens !
Cheers,
Steve
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