On Jul 13, 2005, at 9:36 PM, Shel Belinkoff wrote:
I suspect that the perspective would be different too. I think a
cropped
18mm image will still show the exaggerated perspective of that
lens. The
background will appear to be much further behind the subject than
it will
in the image taken with the 28mm lens. That's my theory anyway.
Then Godfrey said:
Citing "Basic Photography" published by Focal Press, ca. 1968-73
Edition:
"Perspective is a function of distance, not focal length. ...
Focal length
along with format dimensions determines field of view."
I think you are confusing perspective with "wide angle
distortion", which
is the effect in a rectilinear corrected lens of causing circles
to become
ovoid when off the lens axis as you increase field of view. An
18mm lens on
a 16x24 format will present the same field of view as a 28mm lens
will on
35mm format, and wide angle distortion will be constrained to be
the same
due to the fact that the field of view is identical (presuming equal
rectilinear correction, of course).
Headache time ... I think we'll just put the 18mm on the digi and
the 28mm
on the filmi, place the cameras on the same spot, and take a
picture, and
then look at the results.
Please do. The distinction between perspective and wide angle
distortion is quite important, and was part of the curriculum I
taught to high school students way back when. That's why I know the
book "Basic Photography" so well.
I'll try to do the same and post the results. I guess I'll have to
load some film into the MX, eh? I wonder who can process it quickly
around here... ;-)
Godfrey
