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View Full Version : 90mm lens sharpest aperture



robc
4-Dec-2006, 08:09
if you have a 90mm lens, which aperture do you consider to be its absolute sharpest ignoring dof.

Walter Calahan
4-Dec-2006, 08:58
What does it matter? Sharpness is only a tool for translating one's vision to paper.

What if my 90 mm goes to f/128?

Doug Dolde
4-Dec-2006, 09:13
This is stupid. Why do you think its the same for all 90mm lenses?

Christopher Perez
4-Dec-2006, 09:49
For the typical commercially available 8 or 10 element biogon design lenses the best resolution appears to be f/16. Mil-spec biogon designs (such as the original Biogon) are diffraction limited from wide open.

Wide field designs behave differently.

Patrik Roseen
4-Dec-2006, 15:56
I can not really answer the poll...due to lack of used apertures.

However, the discussion about aperture, sharpness and DOF is interesting.

I have this wonderful book called 'Photographing Water in the Landscape' by David Tarn. Every photograph includes information about the lens used, the time and aperture.
It struck me that almost all photographs were made using f/22. Same for both 4x5" (90mm,150mm, 240mm) or 6x7 regardless of lens used. The photographs include both far and near objects. I think he is using modern plasmat lenses.