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Re: [APML] Layers (8 vs. 16 bit images)
Hey Dick,
Thanks for the input. Don't worry, you're not too far behind on this
discussion. I'm thinking of asking for some of these "learn Photoshop"
manuals for X-mas and was wondering if the one you refer to is too
technical for beginners, in your opinion. I'm willing to put the time
in but the material has got to be at a level I can work with.
Thanks,
Alan
--- "Dick L." <rlocke1@houston.rr.com> wrote:
All, I now get the AP digest, which seems to arrive semi-monthly, so
I'm usually going to be way behind on anything I contribute.I followed
8 bits using layers discussion with interest, some of which is below.
I previously went along with the conventional wisdom, that 16 bits was
way better than 8 bits. (And Adobe wouldn't want to discourage this
thinking, as it helps facilitate sales of CS. Hardware vendors are
kind of in the same boat.) Dan Margulis in "Professional Photoshop"
(4th ed.) has considerable discussion of 8 vs. 16 bits. Based on a
good deal of experimenting, he basically concludes that "real world"
differences in working with 8 vs 16 bits are negligible. (I realize
that astrophotography is borderline real world, but nonetheless I think
he's right.)So: I wouldn't let the 8-bit conversion in PS7 stop me from
working with layers, if layers are called for. And there's a lot you
can do with layers that you can't do otherwise.What I do now is capture
and save in 16 bits from my camera/scanner. Allow the scanner/camera
to do absolutely no image processing. I then open an image in PS, and
adjust curves or levels if there's any kind of gap in the histogram
(i.e. if the curve ends before the top or bottom of the scale.) I then
convert to 8 bits and don't look back.BTW, while this book is not for
the faint of heart, it's really taught me a lot. The powerful
techniques of blending one channel into another are covered extensively
- and you need to use layers to do it
=====
SCT Astrophotography: http://www.pbase.com/avoetsch/astrophotography
FS-102 G-11/Gemini: http://www.pbase.com/avoetsch12952/tak_fs102
& http://www.pbase.com/avoetsch12952/fs102
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