Re: 8 bit vs 16 bit workflow
Re: 8 bit vs 16 bit workflow
- Subject: Re: 8 bit vs 16 bit workflow
- From: "Martin [apple account]" <email@hidden>
- Date: Sun, 05 Aug 2001 10:46:38 +0100
on Fri, 3 Aug 2001 10:31:40 -0700, email@hidden (Bruce Fraser) wrote:
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Images that tend to posterize during color conversion (gradients,
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skies, etc.) tend to do so much less when you do the conversion at
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16-bits/channel.
In theory yes, but do you have any examples that you can show others?
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Color neg absolutely needs 16 bits, IMHO. It captures a much wider
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dynamic range from the scene than does transparency film, and you
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need the extra bits to do the necessary tonal shaping and compression.
That is/was my belief also.
However, I have a bug in my scanning software that means that I have two
choices when scanning negative:
1. Scan in 16 bit mode (genuine 14bit) of the raw negative and then have to
invert and do colour work in Photoshop
2. Scan in 8 bit and be able to carry out inversion and colour manipulation
during scanning -- resulting in clean 8 bit positive image
So, in the belief that I am short changing my clients by not scanning negs
in 16 bit mode, I scan lots of image in twice and compare the results.
What do I find? Bugger all difference.
Now, it may just be that I don't have big enough range of source negs to
work with -- all the photographers that supply negs to us are mostly
shooting on 5x4 inch or sometimes 6x7 cm.
If you have a sample image that was scanned in 16 bit and then transformed
in such a way that an 8 bit version of the original would give noticeably
inferior final results -- show me!
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The other reason I use 16 bits is that my film is precious and
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fragile. I only want to expose it to the rigors of scanning once, and
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when I do so, I want to make sure that I've captured everything the
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scanner can pull off the film.
That's why I prefer using flatbeds for all but the most difficult images.
The sound of an oil-mounted transparency coming loose from a drum at 250 rpm
is most unpleasant!
--
Martin
Idea Digital Imaging Ltd - the "image" specialists
http://www.idea-digital.com