Originally posted by esipentax I just purchased a Pentax K10D. After copying files to my PC and opening with Photoshop CS 2007, the image resoluton is only 72 pixels per inch. (My inexpense Kadak Easy Shagre camera files come in at 255 pixels per inch.) I took the pictures at 10 megapixels and highest resolution setting.
Understanding Resolution
I agree with the previous poster, but you might give the above link a read.
PPI is not an intrinsic attribute of the file, rather an expression of the number of pixels in an output. I.E. on a monitor it is 72 or 96, on processed digital sliver halide paper it will be much higher.
Honestly tho, I don't know what the maximum output resolution is for digital sliver halide prints. This guy claims 1200 DPI
AIM: Silver Halide Resolution
Anyway, if you want the absolute maximum in clarity from your prints, you want at least 1200 PPI for a given physical size. I.E. 4x6 or 8x10 or whatever.
Personally, when sending a print off to a finisher, if the resolution at the desired dimensions is above 600 PPI, you'll have a fine print -- 300 PPI is probably minimum.