This problem is often due to the plasticizers or mold release agents evaporating from the plastic surfaces from heat after the scanner is built. SOmetimes even the materials used in packaging the scanner may off-gas materials that deposit of the glass bed.
These scanners travel by slow ship and often go through considerable temperature changes. First, make sure the fogginess is on the inside surface, by carefully cleaning the outer surface well. As to how much the fog degrades the image, it somewhat depends upon the degree of "fog" the type of lighting and image sensor, and the thickness of the glass. If there is an area, as you indicate, which is not foggy, you may wish to scan the same material in different areas of the scanner and see if the results are different, keeping in mind that all flatbed scanners have a "sweet spot" where they scan the best (usually a column down the center of the length of the scanner bed). The bottom line is that scanners really shouldn't have residue on the internal glass surface, and this should be covered by warranty. You might try an exchange and see if the next one is cleaner. Sometimes service techs will end up removing the fog during a cleaning but add other dirt or contaminate the image sensor. These scanners are put together by robots and people in clean rooms (in theory, at least) and whenever they are opened, the risk of new dirt entering exists. Art Robert Meier wrote: > I have just purchased a CanoScan 9900. After installing the unit I realized > that the glass on which the film/document is placed is "foggy". You can see > this best when the scanner light is on and look almost parallel to the glass > plate. The part closer to the back is more "foggy" then the other side. Also > there is a small clear part so it's definitely not just a property of the > glass. Has somebody else discovered that on this particular scanner or other > scanners? Is this typical? Does it affect image quality from a practical > point of view? > > Robert > > ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body