> OK, be prepared to be surprised. Pull down the Image menu, go to Mode and > gaze at the two entries "8 Bits / Channel" and "16 Bits / Channel." > I've been using it for years; it ain't new.
> Yes, the Wikipedia article seems to verify what I was saying; that the same > file can be referred to a 8-bit or 24-bit and both terms can be correct, > depending on how you apportion the bits. I think the key here is one has to indicate, for clarity sake, that the reference is to "per channel"--but then, to be precise, one should indicate how many channels are involved and what color mode. There is a reference in the Photoshop help file: <begin quote> In most cases, Lab, RGB, grayscale, and CMYK images contain 8 bits of data per color channel. This translates to a 24?bit Lab bit depth (8 bits x 3 channels), a 24?bit RGB bit depth (8 bits x 3 channels), an 8?bit grayscale bit depth (8 bits x 1 channel), and a 32?bit CMYK bit depth (8 bits x 4 channels). Photoshop can also work with Lab, RGB, CMYK, multichannel, and grayscale images that contain 16 bits of data per color channel. Additionally, Photoshop can work with RGB and grayscale images that contain 32 bits of data per color channel. <end quote> > http://www.luminous-landscape.com/tutorials/bit-depth.shtml, among > other industry sources ... I think the reference to RGB and printing is just some poor editing/writing--I don't think the writer was actually saying printers print in RGB. Since the website is photography-based (rather than commercial printing), inkjet printers are often thought of as RGB printers because they like to get their data in RGB and then convert to CMYK (or CcMmYKk, CMYKOG, etc.). As an aside, one only needs about 200 shades of gray to get a decent photo from commercial printing. It is the line screen (LPI), the resolution of the output device (DPI), and the resolution of the image (PPI) that are critical. Again, I think the website was dealing with photograph printing. David Creamer I.D.E.A.S. - Results-Oriented Training http://www.IDEAStraining.com Adobe Certified (since 1995) for ALL Print and Web Publishing-related software Authorized Quark Provider (since 1988) Markzware, Enfocus, FileMaker Certified Apple Certified Consultant (since 1990)