Digital BW, The Print

Duane is absolutely correct, and this is a thing which many photographers
misunderstand.  Depth perception is a function of the relative distance of
the objects in the scene from the taking camera.  Cropping of a negative is
in fact equivalent depth perception wise to using a longer focal length
taking lens and putting the same subject area onto a larger negative area.
Most photographic training, formal and informal, mis-represents this
important fact.

Consider what is a "normal" lens on a 6cmX6cm negative camera ... something
in the 80-100mm range.  Yet a "normal" lens on a traditional 35mm camera is
in the 45-55mm range.  A standard 35mm still camera negative frame is about
24mmx36mm, or just over 1/2 the width of a medium format negative.
Unsurprisingly, the ratio of "normal" lenses between the two formats is
about the same as the ratio of negative sizes.  Now, shoot with a 6X6 and a
100mm lens, but crop to the equivalent of a standard 35mm negative and you
do in fact get the same perspective as if you had shot with a 100mm lens on
a 35mm camera body in the first place.

The math for depth of field is a slightly different kettle of fish :).  

John



-----Original Message-----
From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of dlruckus

HI. Not to be picky either but perspective is a function of position, not of
lens focal length.

Regards
Duane