On Thu, 17 May 2007 18:45:32 -0400, John <look@sig.net> wrote: >On 16 May 2007 21:39:01 -0700, Yeoman <sleepingrass@gmail.com> wrote: > >>Can anyone suggest an appropriate resolution for scanning old >>documents? They are from around the 1850s and are written in slightly- >>faded quill pen. I want to preserve as much of the detail as possible >>without the scans taking up a huge amount of space. Is there a happy >>medium between quality and size? > >I scan most paper (pictures or documents) in color at 300dpi; my >latest project has currently has 1500 scanned images (out of about >2000 total pieces) and is 5.6GB. The thumbnail files (no more than >600 pixels in width or height) aggregate to about 300MB (so it will >fit on one CD for distribution to others). The old pix and newspaper >clippings seem more "real" to other people if the original sepia/brown >tones are maintained - any prints made from these scans also look more >"real" to other people (my preference is gray, but there are about a >dozen relatives who have some interest in the family history; having >color images of non-color documents caters to them. > >I find that gamma changes (usually reducing it to 0.3 to 0.6) increase >the contrast enough to make handwritten notes legible - sometimes >changing the gamma for each color separately gives the best image (as >long as you don't care about color accuracy .;-) > >John I also usually scan documents at 300 dpi. Depending on what the original looks like I'll do gray scale if it is black and white and color if it is either in color or detail can be seen better in color. Unless it's a pristine printed page I've found that black & white scanning usually loses a lot of detail. I normally scan photo's at 600 dpi. That seems to be the sweet spot for me on quality versus file size. Normally the file size is between 5MB to 100MB depending on the physical size of the photo and whether it's black & white or color. 600dpi enables me to zoom in and see details that you can't normally see in the physical photo. With the documents that you describe I probably would treat them as photos and scan at 600dpi either in gray scale or in color depending on what the document looks like. I have a small portable Canon scanner that I take with me with my Tablet PC that does the job for me. I haven't tried the camera method. I've got a 4 mega pixel camera so that may work well on large documents or when I don't have my scanner. Hope this gives you another perspective. Good luck on your scanning.