Consider that using a lens intended for the 35mm format on a camera with a
half-size sensor really just amounts to in-camera cropping. The perspective,
depth of field, and everything else will be the same as if you shot the scene
on 35mm film and then cropped out the digital-size portion.
The receptor of the image has, or should have, unless it's defective, no effect
on the image itself. If I look out the kitchen window and see an elephant in
the front yard and I yell to my wife, "Come here and look at this ***ing
elephant in the front yard!" I would be more than surprised if she came, looked
out the window and said, "Elephant? That's a rhinoceros, you moron!" Same
thing here. Whether it's a whiz-bang digital sensor or a primitive piece of
Plus-X, the picture projected onto it is the same in every respect. It's just
that with a smaller format receptor, you don't get the whole picture, and if
it's an elephant, it's just going to be part of the elephant.
Walt
--
"Anything more than 500 yards from
the car just isn't photogenic." --
Edward Weston
-------------- Original message ----------------------
From: "Michael R. Collins" <michael789@xxxxxxxxxxxx>
> >...A 24mm lens ... always and forever projects the same image out
> >its behind relative to the scene in front of it, meaning, assuming
> >the lens-to-film (or sensor) distance is correct, even the
> >foot/meter distance scale will be correct, and, obviously, the COC,
> >DOF and FOV will be the same.
>
> Walt, this is where you lose me. No question the *projected* image at
> the sensor, whether it's 35mm film or 110 film or 8x10 film or small
> or large digital sensor, will have the same "sharpness" in that plane
> regardless of the sensor type or size. However, I have always
> understood DoF to be dependent not only on the lens but also the
> format - 35mm, MF, LF... (and also on assumptions made about viewing
> distance and quality of eyesight, but factor those out for now). For
> any given format, you use a factor (e.g., typically 5x for 35mm, less
> for MF and even less for LF) to account for a *viewed* image as
> opposed to the image projected on the sensor.
>
> The answer to the "digital DoF" question, then, would depend on the
> factor used, and is the same as for 35mm only if the factor is the
> same, which I doubt. I'm off to search the literature; no idea
> whether I'll find anything.
>
> There's a further issue of CoC vs. pixel size, which can be left for
> the next discussion :-) .
>
> Michael
> --
> Michael R. Collins ... Michael.Collins@xxxxxxxxxxxxxxx
> Toronto, Ontario, Canada
>
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|