Original Message:
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Wrom: ZFSQHYUCDDJBLVLMHAALPTCXLYRW
Date: Sat, 4 Jan 2003 14:43:18 -0500
To: olympus@xxxxxxxxxxxxxxx
Subject: [OM] The coming generation of 35mm CCD digital cameras
I just read the February 2003 issue of Outdoor Photographer.
On page 23 is a full-page ad for the new Sigma SD9 camera, the one based
on the Foveon chip. The ad claims "over 10.2 million photodetectors, to
sense red, green, and blue light at each pixel, unlike image sensors that
process only one color per pixel". From the careful distinction drawn
between "photdetectors" and "pixels", I would guess that 10.2 is the
marketing pixel count, and that there are 10.2/3= 3.4 million tricolor
pixels per image, with a 1:1:1 ratio. The camera weighs 805 grams (28.4
oz, 1.76 pounds). No price is stated in the ad. Camera also reviewed in
DP Review: <http://www.dpreview.com/reviews/sigmasd9/>, where the price is
reported as US $2,000 for the body only. From an earlier DP Review: "This
new camera has a 3.43 megapixel (effective) X3 sensor which outputs 2268 x
1512 x 3 pixels. Each pixel is 9 microns [square] which makes the sensor
20.7 x 13.8 mm (a 1.7x focal length multiplier)." So, there are 3,429,216
tricolor pixels, and the same number (3!
.43 million) of green pixels.
-snip
Joe Gwinn
I am getting very suspicious of pixel counting. DP Review seems to
indicate that the Sigma is better in some ways than a 6 megapixel
Canon, but significantly worse in others. One would think that with
nearly twice as many pixels the Sigma would be substantially better
in the same way that a 4 megapixel image would be over a 2 megapixel
image. Fuji's diagonal array seems to be much better than the usual
rectangular array with the same pixel count. This stuff is really
just getting started.
Apparently Sigma has a 2 year lock on the Foveon technology. So,
considering the drastic depreciation of third party lenses and the
Sigma and the Foveon chip become much more expensive compared to
Canon or Nikon.
An interesting thought occurs to me. Some of the digicam reviews
compare to the reviewed camera to its competitors in the images
produced. It would be interesting and informative to me if, at least
for the pro level cameras, to provide a base comparison to the same
test subject taken with a good, pro level film camera scanned at 4000
dpi.
--
Winsor Crosby
Long Beach, California
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