TECHNICAL INFORMATION 4
OUTPUT-SPECIFIC PROCESSING

Output-specific processing is also done in Photoshop and depends on the specific display formats and size:

For web use, I reduce the image size (down-sample) to a typical width of 600 (more recently, 900) pixels or height of 450 (600) pixels, whichever is less, apply unsharp masking, and save in JPEG format (typical file size of 30k-40kb). I then downsize again to about 150 x 100 pixels for thumbnails & save another version at that size.

For prints, I normally use a file with resolution of 260-300 pixels per inch (if I started with a scanned slide or high resolution digital image) or 240 pixels per inch (if I started with a digital capture from my 6 megapixel Canon EOS-10D) for the desired output size; for example, an eight inch by 10 inch print would be 2400 by 3000 pixels at 300 dpi or 1920 x 2400 at 240 dpi. A full 35mm frame from the scanner at 4000 dpi results in an image approximately 4000 by 6000 pixels, which nicely supports a print at 300 dpi of up to 13.3 inches by 20 inches. Since my Epson 1270 and Epson 2200 printers can handle a maximum paper size of 13 inches by 19 inches, they are almost perfectly matched to my scanned 35mm film images. Unless I have cropped the image significantly and still wish to make a 13 by 19 inch print, I never need to upsample when starting with an image scanned from film.

Digital is a more variable situation, depending on the resolution of the digital camera used. My old 6 megapixel 10D camera produced a file of about 2000 by 3000 pixels, which supports a print size of 6.6 by 10 inches at 300 dpi or 8.3 by 12.5 inches at 240 dpi. To make prints up to the 13 by 19 inch capability of my printers, I must upsample. Printing with 240 dpi files means less upsampling, though I'm not sure I can really see the difference between 300 dpi with more upsampling or 240 dpi with less. I don't theoretically like the idea of upsampling, but on most images I've taken, when viewing the final 13 by 19 inche print from a couple of feet away, I can't really see any difference between up-sampled digital images and scanned film images. Probably the various limiting factors of lens sharpness, film resolution and grain, and camera shake (when not using a tripod) are all acting to limit final sharpness in addition to just pixels per inch. The 1Ds MkII camera produces a file of about 3333 by 5000 pixels, which nicely fits a 13" x 19" paper size by printing at about 260 dpi.

I then apply unsharp masking, select the appropriate printer/paper/ink profile for the paper being used (usually Epson Premium Glossy or Epson Matte Heavyweight and always Epson OEM inks), and send the file to my Epson printer. I don't use my older Epson 1270 (dye-based inks) much anymore. My Epson 2200 (pigment-based inks) is rated at much longer print lifetime before significant fading takes place and both produce a similar color range, so the 2200 has been my choice for the past several years. Prior to spring 2007, I used both Epson OEM profiles and profiles purchased from Inkjet Mall in Vermont http/www.inkjetmall.com). In 2007 I purchased the Gretag-Macbeth Eye-One Photo profiling system and now make my own custom profiles for my specific printer with whatever paper I wish to use; I still use only Epson inks.