Re: How important is Oly's dust reduction system?

Robert Schroeder wrote:

I follow your arithmetic, but where does the Fuji F10/F11/F30 fit in there? If I extrapolate their results to FourThirds or to APS-C sized sensors, I arrive at 35 to 50 megapixels with only barely visible noise up to at least ISO 800.

I looked up the F30 and it has 2.9 micron pixel spacing. A general
rule is a sensor's full well is 1000 times the area of the pixel
(rough but usually within a factor of 2), so 2.9 microns is
about 8.4 square microns, or about 8900 electrons, But small sensors
seem to be doing better (I don't know why), so let's double it,
and you get about 18,000 electrons, which is roughly similar to the
S60 full well which has similarly sized pixels.
Thus mid histogram would be about 18000/20 = 900 electrons
at ISO 50, for a S/N ~ 30. At ISO 800, it would be only 7.5,
plus degraded more by read noise.
You may actually perceive higher S/N in tif converted images as the
raw conversion process averages pixels, sacrificing spatial resolution.

Interesting that you say you see barely visible noise at ISO 800 on
a small pixel camera. I guess everyone has different standards.
For me, noise in 1D Mark II images is too much at ISO 50, and
this is one of the highest S/N cameras around, giving
mid histogram ISO 50 S/N ~ 63. At ISO 800, that drops to ~18,
and read noise is negligible at that level.

In general, the larger pixels produce better images, but
S/N scales linearly with pixel size, while cost does up
faster (approximately), so everyone must decide where their
trade point is of quality versus cost (and weight and bulk).

For me, the cost, weight and bulk is worth it to get images like these:
http://www.clarkvision.com/galleries/gallery.bird/web/great.blue.herons.the.kiss.JZ3F8149.f-700.html
http://www.clarkvision.com/galleries/gallery.bear/web/brown_bear.c09.07.2004.JZ3F1314.b-700.html
which I would not get from a F30, or non DSLR camera. With a small
sensor camera I feel I could not make sharp 16x24 inch and larger prints that
meet my standards. And besides, lugging around all the equipment helps
keep me in shape ;-).

Roger
.

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