Archived from groups: rec.photo.digital (
More info?)
"Mikal" <accclass101@hotmail.com> writes:
> Rather old digital back,
Introduced in 1995.
> but, the manual says it'll do ISO 80 with 18MB color images, and ISO
> 160 in monochrome at 6MB images. For some reason, this camera does
> 6MB color images at ISO 80. Theirs an 'ISO' button, that your
> supposed to use to switch between ISO modes, but it just stays at
> ISO 80. The camera has hardly been used. It's annoying. any ideas?
You haven't RTFM careful enough :-) .
All Kodak DCS46xx backs used the Kodak "M6" 28 x 19 mm 6 Mpx sensor.
The DCS456c you've got is a colour version made to fit Hasselblad,
Sinar, etc. (with rather large crop).
The same sensor is used in the DCS460c back that attached to the the
Nikon F90s - and the spcs. are identical. You can see some data on
the DCS460c here:
http://folk.uio.no/gisle/photo/dcs460.html .
The "c" in the DCS465c indicate you have the *colour* version.
There was also a DCS465m *monochrome* version. This was a
physically different unit (same M6 sensor, but the colour version
was manufactured with a Bayer colour filter array as an integral
part of the chip). Your manual actully describes two different
backs - not two different "modes" of the same back. There is no
way to convert between the DCS465c and DCS465m. Removing the Bayer
array will destroy the chip.
The Bayer filter array steals about one stop of light. Hence the
difference in ISO between the models. Despite the 'ISO' button
there is absolutely no way to change ISO (or to make it into a
monochrome sensor). You are stuck with colour and ISO 80.
As for image file size, the RAW TIFF files produced by the colour
back is 6 Mbyte. When you de-mosaic them to "standard" RGB TIFF
files, they become 18 Mbyte. If you read the manual, you'll notice
that it distinguishes between "unacquired" (i.e. RAW TIFF) and
acquired (i.e RGB TIFF) file sizes.
Btw.: The monochrome version is rare as hen's teeth. I'm looking for
one, and I've never seen one for sale that has been the genuine
article. (You sometimes see some fast operator claim they have the
mono version - but when I check - it turns out that what they offer is
a colour model bundled with some lame software to desaturate).
--
- gisle hannemyr [ gisle{at}hannemyr.no -
http://folk.uio.no/gisle/ ]
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Kodak DCS460, Canon Powershot G5, Olympus 2020Z
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