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You need an image viewer. Don't fight it. Get one.
 technofile
Al Fasoldt's reviews and commentaries, continuously available online since 1983

T e c h n o f i l e
JPEGs, image viewers and more tips and tricks for photo editing


Nov. 21, 2004


By Al Fasoldt
Copyright © 2004, Al Fasoldt
Copyright © 2004, The Post-Standard

   Each time I write about scanning and digital photography, I get a flurry of letters asking a lot of basic questions. This week I'll try something new. I'll answer the most common questions before they get asked.
   Q. I know you've said this many times -- "Don't save your pictures as JPEGs. Use a lossless image format instead." But you're forgetting that most cameras use only the JPEG format. Photographers don't have any choice.
   A. No problem. Just convert those JPEGs to a lossless format as the first step before you edit or crop the pictures. JPEG (also spelled JPG) is a way to reduce the file size of mages, and it's ideal for creating photos you can easily put on Web pages or send as attachments in e-mail. But JPEG compression removes parts of the image. When you work on a JPEG photo and then save it, you make the problem worse.
   As soon as you get the pictures out of the camera, save them in a lossless format and work ONLY on the lossless versions. (Save the original JPEGs in case somethng goes wrong.) A good choice of a lossless format on Windows is BMP or PNG; on Macs or Linux, it's TIFF or PNG. Windows users can also use TIFF, and Mac users can .... or, well, you get the point.
   Q. I switched to a new image-editing program and now my scanner still tries to use my old program.
   A. Look for an "Import" or "Acquire" function in your new software. Use it to activate your scanner. If your new software doesn't have such a function, try running your scanner software on its own; most will do that nicely. Use the options or preferences menu in the scanner software to have the scanner save each scan as a file. Later, you can open each saved image in your favorite image editor.
   Q. You keep harping on the need for a good image viewer. But I've got this really great photo edting program that came with my scanner. And my camera came with another really great photo editing program. They're wonderful. Really great. Superb. I don't need an image viewer, so why can't you recognize that not everybody needs an image viewer?.
   A. Because there are no "really great" photo editing programs that double as image viewers. An image viewer is a small program that springs into action to do one thing -- display the image full screen -- when you double click on an image. That's all it has to do. "Really great" photo editing programs can't do that because they're big and porky.
   The only time you don't need a good image viewer is when you don't want to be able to see your pictures quickly and easily.
   Q. My brother-in-law scans his slides with his flatbed scanner. You should see how good they look on his screen! Why do you keep saying that flatbed scanners can't be used to scan slides?
   A. I didn't say that. I said flatbed scanners SHOULD NOT be used to scan slides. I know that they CAN be used. You can cut your grass with scissors, but a lawn mower works a lot better. Likewise, a slide scanner does a better job scanning slides and negatives than a flatbed scanner.
   In one area alone, resolution, the flatbed scanner falls far short: A good slide scanner needs 1800 dpi or more of optical resolution, but consumer flatbed scanners usually have 300 dpi of optical resolution. Note that I'm referrring to optical measurements, not the claimed resolution, which is nearly always exaggerated.
   Q. My scanner automatically adjusts color and stuff like that when I scan, but my scans seem to come out too dark. What am I doing wrong?
   A. Three possibilities:
   1. You're not cropping the image before you scan. If the scanner sees the white edges of the print as part of the picture, it will darken the entire image because the bright border fools the auto-sensing system.
   2. Your monitor is not calibrated. You don't have to spend money on a display calibration system; just make some basic adjustments by putting the contrast as high as possible and then backing off slightly and then looking at a totally black area and backing off on the brightness until you see no gray at all. (The brightness probably will end up turned 'way down; that's OK.)
   3. Your scanner needs a boost. Make some test scans, adjusting the scanner's controls a little each time, and see what works best.