Comments below.
At 3:06 AM +0000 1/6/03, olympus-digest wrote:
>Date: Sun, 5 Jan 2003 09:31:37 -0800
>From: Winsor Crosby <wincros@xxxxxxxxxxxxx>
>Subject: RE: [OM] The coming generation of 35mm CCD digital cameras
>
> >
> >Original Message:
> >-----------------
> >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.
Yes. It's like clock megahertz in computers, but the full story is far too
complex, so people use the single number despite its limitations.
Foveon claims that their sensor, having overlaid RGB photodetectors, suffers
far less from the various artifacts that plague other digital cameras.
I think the whole area will settle in five years, when the sensors will have
sufficient pixels to simply overwhelm the various artifacts, as these artifacts
are mostly due to undersampling and the compromises necessary to ameliorate the
more disturbing consequences of that undersampling.
>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.
I don't understand -- what point are you making?
>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.
Yes.
Joe Gwinn
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