Archived posting to the Leica Users Group, 2004/02/02
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At 6:50 AM -0800 2/2/04, Slobodan Dimitrov wrote:
>The Shutterbug talk made me think about it. And I'm going from memory here.
>They had a piece on the 4 gig flash card. In it, they say that with current
>cameras it turns into a 2 gig card, as one would need a 32 bit system to
>activate the 4 gig capability. That can only mean one thing, a 32 bit camera
>might be in the pipeline somewhere.
>S. Dimitrov
In this case 32bit refers to the file allocation system. The 16bit
system used on most cameras (whether they produce 8bit/channel or
higher images) can only address up to 2Gb. The 32bit system, called
FAT32 (for File Allocation Table) can address terabytes, and is
necessary to make use of anything over 2Gb.
Most digital cameras have sensors that capture more than 8
bits/channel, but most reduce this to 8 bits to be able to output the
files as JPEGs. That's standard JPEG, as understood by most of the
industry, not JPEG2000, which can handle high bit images, but is
understood by few programs.
Cameras that can output RAW, or NEF, or DCR output more than 8
bits/channel. Generally 12 or 14 at this time. Software is then
needed to convert that to a useable 16 bit/channel file that
Photoshop can deal with, or reduce it to 8 bits than any program and
the web can deal with.
So the Canon D60 and the 10D are both high bit cameras, in that they
can produce RAW files than can be converted into 16bit/channel (48bit
RGB or 64bit CMYK) Photoshop files, but the D60 is not FAT32
compatible, and thus using 4Gb cards in it is pointless, as it can
only access 2Gb, while the 10D is FAT32 compatible, and can make use
of any card now and in the next number of years.
- --
* Henning J. Wulff
/|\ Wulff Photography & Design
/###\ mailto:henningw@archiphoto.com
|[ ]| http://www.archiphoto.com
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