Bob Smith writes ... > Nope, Thomas was correct. High bit depth scanners (or cameras) often > do capture a higher dynamic range but its not *because* of the > increased bit depth. High bit depth often comes with other higher > quality components that yield better dynamic range and that may be the > source of this common misconception. The dynamic range is not confined > by bit depth at all. Bit depth only defines the precision of > measurements between black and white. It has nothing to do with > determining how dark the darkest object is that is represented by the > lowest number on the scale or how light the lightest object is that is > represented by the highest number on the scale. Bit depth only > determines how many steps there are between minimum and maximum.
What you and Thomas say is true, but the sensors which scan (e.g.) film have to acquire linearly (maybe "linear" is the wrong term, but they're not flexible ... an analogy would be trying to measure 14 inches with a foot-long ruler). If they cannot acquire data with enough depth, then they cannot be told to acquire the entire range. Its not problem anymore, because all sensors are at least 12bits, and after the data is acquired the conversion to 8bits is as you claim. cheerios ... shAf :o) Avalon Peninsula, Newfoundland www.micro-investigations.com (in progress) =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
