Message-Id: <mailto:199507101404.JAA26531@library.wustl.edu> Date: Mon, 10 Jul 1995 09:00:54 CST From: David Riecks <mailto:riecks@CC-MAIL.AGCOMED.UIUC.EDU> Subject: Re: 2400 dpi slide vs. 600 dpi photo scans To: Multiple recipients of list IMAGELIB
On 7/8/95 mailto:fhung@globe.com.ph wrote>I am very curious as to what type of scan would give a better,
>clearer picture:
>- a slide scanned using a 2,400 dpi (24 bit color) slide scanner
>or a
>- a regular photograph scanned at 600 dpi (24 bit color) using a
>flatbed?
You are correct that the slide scanner does scan at a higher rate than a flatbed scanner, but your print would have to be bigger than your standard 3 x 5 to get a larger resulting file of data. Actually 3.78 x 5.67 inches would be the same file size as a full-res 2400 dpi scan of a 35mm slide.
The other factor you have to consider is dynamic range of the image. The slide scanner is designed to handle an image with much higher contrast than the flat-bed (ie, it reads into the shadows and doesn't block up the highlights). Not to mention that if you are dealing with photographic images you will most likely be scanning an original slide or negative. With the flatbed, you are generally dealing with a second generation (print from negative or slide). The sharpness and the quality of this print will also influence the quality of the resulting image as well.
Personally I alway try to stick as close to the source material as possible. Just my $.02 worth.
David
********************************************************************** *| David Riecks | "There's a fine line between |* *| University of Illinois | fishing and just standing on |* *| mailto:riecks@uiuc.edu | the shore like an idiot." |* *| mailto:71543.1617@compuserve.com | Steven Wright |* **********************************************************************