This is a major point raised by Michael - having a black sheet behind the page you're scanning will greatly reduce the other side of the page's contents coming through when scanning the page you want. This will, of course, mean the scan will come out a little darker, but with some Photoshop restoration, you can make what should be white, white again, along with black and the complete range of tone between white and black.As for using a camera to scan...I've never tried it myself, but somehow I think you're always going to get better scans with a flatbed or sheet fed scanner."Better" may be true, but "good enough" is the point, and a 10Mpixel camera will capture enough information that a Photoshop script can compress the blacks and whites, dropping out the paper texture, and sharpen it so that it can be saved as, say, an 8-level grayscale .GIF that has plenty of "ink" info and none of the "paper" info, ready for a PDF with OCR for searchability. Some prefer a 1-bit BW representation, but that often requires resampling to 300 or more dpi just to get clean edges on the fonts, while 8-level .gifs look fine at 150 dpi. The speed penalty of a flatbed is a serious problem unless you are willing to shear the spine and use an ADF overnight. -michael
Certainly the camera is quicker, if it can capture images completely flat so that no text is distorted, especially around the spine, which is likely unless it's held as flat as possible. As has already been anticipated, that's going to be an issue if you want to keep the magazine intact and not pull it apart. But you can hold it down flat enough that in most cases, it shouldn't be too big an issue for a flatbed scanner - no text should ever go so far into the spine (if it does, it's probably a poorly designed advert). Ensuring a flat image will of course help more accurate optical character recognition (OCR).
For black and white scans, I prefer 1-bit black and white images at at least 600dpi. You should find that you're still getting very good compression (if saving as an LZW compressed TIF, or as a PDF) and when viewing the black and white at that resolution in Acrobat or Mac OS X's Preview, both programs will create anti-aliasing on the fly and display a very nice clean image. Additionally, if you were to print such a scan, you'd also find the print would appear very nearly as good as the original image, because no permanent unecessary anti-aliasing has been added to image.
But you're right, I wouldn't like to be the one to manually scan every page. Using a sheetfed scanner will save time too, but then you won't be able to use a black sheet behind each page to help prevent the other side coming through.
If there's a sheetfed way that minimises the other side of the page's print coming through, than I think you'd be onto a winner in terms of speed and quality.
-- - Alex http://www.whatisthe2gs.apple2.org.za/