hi Mike ;p-)

the canon 10d is a 6.3 MP with 22.7x15.1mm (1.6X) sensor if sources are
right ;-) You can expect a maximum of circa 68 lpmm resolution. So I have
to assume values over 68 lpmm being reported (e.g., 75 lpmm) are results
of post-sensor processing or subjective interpretations of test charts?

Yes, you are right that a smaller sensor size than full format (24x36mm)
means a higher resolution value, which puts more demands on lenses used
with the DSLR etc. It does NOT however mean more pixels, since you still
have 6 MP (actually 6.3 MP for this specific case).

So regardless of the sensor physical size, you have 6 megapixels. When
printed at 8x10" at 300 dpi you still have 5.6 lpmm and all that in my
previous analysis. And the film camera still has a 2X advantage, not
because of its sensor size, but because it is effectively a 24 MP sensor
equiv. (for the full 24x36mm frame). So comparing a 24 MP (film) sensor
and a 6.3 MP sensor, the on print factors remain as I analysized, yes?
;'-)

Now if canon could get a full frame sensor of 24x36mm at that same
density, they would have a circa 16 MP sensor (!). Again, this is
something I have been saying all along too. That 16 Megapixels is the
"sweet spot" for DSLRs, and when cheap 16 MP full frame sensors hit, the
results will be "good enough" for nearly all 35mm film users.

The other thing your post points out, with the above analysis, is that we
evidently agree that it is going to take some rather good lenses, at these
high densities, whether just the central lens area with the current 6.3MP
smaller sensors at these densities (1.6X factor), or with the future 16 MP
version at full 24x36mm frame size.

And to make it relevant to the MF group, you have to have 4X again for
MF's advantage in film, which is why a 64 MP sensor will be needed to
equal mid-speed films in MF (6x6cm). Right?

This is why I object to the claims that the latest 8.2 MP DSLRs are
"medium format" killers. Now 8.2 MP is nowhere close to 64 MP in my book
;-) Are 1.2 MP webcams good enough to challenge today's 8.2 MP DSLRs? No,
for the same reasons ;-) But the 8.2 MP will turn out pretty good 8x10"
and even 11x14" for most users, so they may be "good enough" ;-)

my $.02 again

bobm



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