Anthony wrote:
"What you missed is that as film formats get larger the lens needed to
get a certain angle of view also lengthens, so the amount of DOF getting
onto the film in the first place is less."
With very minor variations, the depth of field is a function of "angle of
view" rather than focal length. Thus a suitable lens selected for 4X5, or
8X10 for that matter, will have the same depth of field - aperture for
aperture as the 35mm counterpart. This applies as long as the reproduced
images are the same size and not enlarged the same degree.
In addition, a large format lens such as the 65mm Rodenstock Grandagon N
offers its highest resolution at apertures between 22 and 32. The depth of
field will be enormous although one would argue that diffraction will cause
degradation. True, however the negative is almost 4 times the size that of a
24x36 35mm frame.
What is also missed is that current 35mm films cannot capture the
resolution of some of our higher quality lenses. In 4X5 photography the lens
need to only be 1/4 as sharp (which is not the case) as lens for 35 mm to
deliver the same amount of sharpness.
Bob
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