Arthur, Thanks for your reply and tips. Your explanation makes sense. Actually, I have a refurbished $30 flatbed scanner that has the same problem - just much worse. I opened this scanner to clean the inside surface of the glas bed. After leaving the scanner on for a long period of time (1 day or so) with the lid closed the fog appears again. Leaving the lid open or even turning the scanner off helps some. So I guess they used really cheap material that cannot stand the quite high heat produced inside this scanner. Maybe that's why the company who made the scanner doesn't exist anymore...:O
Rob >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] Behalf Of Arthur Entlich >Sent: Tuesday, November 04, 2003 3:02 AM >To: [EMAIL PROTECTED] >Subject: [filmscanners] Re: CanoScan 9900 & "Dirty" Glas Plate > > >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 ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
