At 14:20 6/9/02, Tom Trottier wrote:
I prefer sharp, constrasty lenses since it easier to degrade these
qualities later than improve them.
On this I agree. It's far easier to degrade contrast with a fog or one of
several types of soft-focus filters than it is to magically add it back.
The only advantage of a soft lens is that the depth of focus may be
increased.
This is incorrect. Contrast and resolving power are two different
things. In an MTF graph, contrast is the y-axis and resolving power is the
x-axis. Indeed, in lens design the pursuit of both to extremes ultimately
results in a trade-off. Create too much of one and it bites into the
other. Various contributors to the effect are practical lens design
aberrations which affect imagery most at wide open apertures and
diffraction limiting which affects imagery most at narrow apertures.
-- John
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