Re: Full-frame or 1.5 DSLR?

I think you're mixing your parameters in your reply, or doing an
incomplete analysis...

<<a 1.6x 8MP 20D has more lens-resolving power than any of Canon's FF
digitals.>>

The same lens has to deliver MORE lines per millimeter of sensor or
film area in order to get LENS resolving power, this has nothing to do
with frame size. So for absolute LENS performance the 20D is NOT
better off than the 1Ds MkII (unless you can prove that the EFS lenses
have higher ll/mm than the EF lenses (not!), because they use the same
lenses (except for the EFS). For lens performance they are the same!


As for pixels per square millimeter of frame, the 20D does win. 16
million pixels in 24x36 area vs. 8 million in 15x22.5 area computes to
over 18000 pixels/sq.mm for 1Ds MkII vs. over 24000 pixels/sq.mm for
20D. But that does NOT tell the story!

<< It would take 21MPs to have the same pixel pitch as the 20D. >>

Yes, I agree about pixel pitch...I posted a message in another thread
exactly to this point, about why photographers would like a larger
format frame (like FF) with the same pixel pitch as the smaller crop
frame (1.5 or 1.6) to provide results similar to the improved tonality
achieved by MF and LF film photos that take away the viewer's breath in
comparison to the same scene shot on 35mm film...

*But* if you analyze the spec of total pixel count for the same amount
of subject on sensor, the story is different! If the subject on both
formats fits 10% of the total frame length, then the 20D uses 350
pixels for 2.25mm of length on the frame vs the 1Ds 490 pixels in 3.6mm
length on the frame, for the same subject; or 490^2 pixel area vs.
350^2 pixel area for the same subject on sensor. Or 240000 square
pixels in the 1Ds to portray the same amount of subject as 123000
square pixels in the 20D! So the 1Ds wins on tonality due to more
pixels for the same amount of subject on sensor...exactly why LF and MF
images have tonality advantage over 35mm images for the same subject.

I own the 20D; I cannot afford $8k for a single 1Ds MkII camera, so the
analysis does not bother me. Your statement is wrong about the
comparative performance of the 20D vs. the 1Ds MkII (or even vs. the
1Ds MkI).

--Wilt

.

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