Lens focal field - Printable Version

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Lens focal field - absk - 03-14-2011

I have noted that macro lens generally have higher edge sharpness than other lens. Has consideration been given to report sharpness (MTF) using subjects other than flat charts?

From my early days in photography (ie. before scanners) my macro (copy) lens (50mm f4.0) was good for flat subjects. The normal lens (50mm f1.4) had almost a concave spherical focal field. Another normal lens (50mm f1.8) had a focal field that laid between these lens.

As such, when arranging a group photo, people would be best arranged in a straight line. When using the two normal lens, people would be best arranged along the appropriate curve. The normal lens made a decent enlarger lens, but the f1.4 lens was not at all appropriate. The f1.8 lens could be used a an emergency copy lens.

Tests indicating this type of information would be useful in determining the use of a lens. Being able to differentiate determine edge softness due to being out of focus and other lens flaws would be informative.