novice9 Posted January 10, 2010 Share #1 Posted January 10, 2010 Advertisement (gone after registration) If I am working in an M9 DNG (uncompressed), why is it that all of the programs show the values for each of the 3 channels (RGB) on a 0-255 scale. Should 16 bit yield up to 64k permutations? Not that it really matters, just want to understand better. thx. Link to post Share on other sites More sharing options...
Advertisement Posted January 10, 2010 Posted January 10, 2010 Hi novice9, Take a look here Basic Question. I'm sure you'll find what you were looking for!
Luuk Posted January 11, 2010 Share #2 Posted January 11, 2010 The 256 levels is the standard for the 8-bit depth files. When 16-bit was introduced the interfaces remained the same for both modes. Easyer and cheaper tot develop. Also the panels would have to be much bigger to show 64 k different levels.One has to be a real tweaker to down arrow through these! Don't you think? Link to post Share on other sites More sharing options...
Marquinius Posted January 11, 2010 Share #3 Posted January 11, 2010 But all in all it's one of those questions that make one think "What?", followed by "euhmmm, that's not such a bad question". Link to post Share on other sites More sharing options...
adan Posted January 11, 2010 Share #4 Posted January 11, 2010 While the numerical values are still apparently "8-bit", the histogram (at least in Photoshop) tracks more accurately. Make a major tonal change (say, in "curves") to an 8-bit file, and you'll see the histogram permanently "comb" as moving the tones around leaves some levels empty. Make the same change to a 16-bit file, and the gaps will fill in again once you exit the "curves" dialogue, as the extra data kicks in. In the raw development stage (ACR, C1), the histogram never combs, since even with compressed DNGs, the data has been expanded back to 16-bit on opening. But even the histograms still only have 256 slots (256 pixels wide) - a histogram that actually showed all 64K levels discretely would be 64K pixels wide and not fit on anyone's screen. Link to post Share on other sites More sharing options...
roguewave Posted January 11, 2010 Share #5 Posted January 11, 2010 If you want to understand what you're working with, get a good Adobe Photoshop book like Martin Evening's Photoshop for Photographers or one of Scott Kelby's books on Photoshop & colorspace. The sooner you understand the nature of the animal, the more enlightened you'll be about what you are, in fact, doing all along the chain of events that unravel after the shutter falls. If you find yourself wanting know even more, read Dan Margulis' books. He is the Lord of Colorspace. Link to post Share on other sites More sharing options...
novice9 Posted January 13, 2010 Author Share #6 Posted January 13, 2010 Thanks all -- frankly, I'm pleased i thought to ask the question in the first place. I started the digital post processing endeavor from scratch 2 month ago when i got my m9, so i'm coming along... slowly.... Link to post Share on other sites More sharing options...
jackart Posted January 13, 2010 Share #7 Posted January 13, 2010 Advertisement (gone after registration) Thank's for explaining. I really experienced big difference between 8 bit and 12 bit depth using LR2. Subtle tone differences as Frost in the Park on Flickr - Photo Sharing! make huge difference. Jaak Link to post Share on other sites More sharing options...
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