I'm scanning old negatives with a film scanner. I can chose from many different settings, such as TIF or JPEG, and various levels of compression. The default setting gives me a TIF with a file size of 67MB. If I capture in JPEG format, excellent quality file size is still 67MB, and high quality gives me 11-14MB files, and good quality is about 5MB. When I edit photos with , the maximum file size the program can process is 16MB, so scanning with excellent settings doesn't seem to make sense. So should I use the Excellent setting, or the High setting? Am I losing any quality, and if so, how much? When I compare the same picture with both Good and Excellent settings, I don't see a difference on my monitor.--Vincent Thompson, Ontario

The answer all depends upon how you plan to use your photos and how picky you are about image quality, Vincent. Consider music lovers for a moment. Many folks are perfectly happy listening to low-quality digital music on tinny ear buds. Me? I consider myself an audiophile; I am meticulous about ripping CDs at 320 kbps (the highest bitrate for the MP3 format). I won't listen to music sampled at 128 kbps or streaming radio. But it turns out that there are even more dedicated audio snobs who put me to shame. I know folks who listen to vinyl only because they think CDs and all digital music, regardless of the sample rate, sounds terrible.

So, back to the issue at hand. If you are scanning these slides as true "archival quality" or "reference quality" originals, then you would want to scan them at the very highest quality possible: TIF, which is a "lossless" format. But there's a cost to doing that because TIF is a cumbersome format to work with. Instead, the highest-quality JPEG is probably good enough if you are not a professional photographer. If you are even more casual about your photos and aren't worried about preserving every bit of color, tone, and resolution, then the Excellent--or even Good--quality setting on your scanner is probably fine for your taste. Of course, if you plan to edit your photos in an online tool like Picnik, you probably aren't concerned about preserving reference quality fidelity in your photos anyway, and lower-quality scans are adequate.

I have seen pictures that completely fill my 22-inch monitor with excellent quality, and when you check the size they might only be 200KB or even less. How do megapixels relate to this?--Shahid Husain, Jackson, Mississippi