Ted,
Some software does the math for you — it chooses the appropriate scanning resolution for the output resolution you are targetting. Not all software does this in a consistant manner, some doesn't even deal with output resolution. So it is a good idea to know how to determine the correct (appropriate may be a better word here) scanning resolution in these cases, if only for a sanity check.
Anthony: there are 8"x10" negatives, so someone cropping to a 6"x7" area would still be well served by your numbers... We just don't see them in Hasselblad or other medium format cameras. 8)
Taras
Some software does the math for you — it chooses the appropriate scanning resolution for the output resolution you are targetting. Not all software does this in a consistant manner, some doesn't even deal with output resolution. So it is a good idea to know how to determine the correct (appropriate may be a better word here) scanning resolution in these cases, if only for a sanity check.
Anthony: there are 8"x10" negatives, so someone cropping to a 6"x7" area would still be well served by your numbers... We just don't see them in Hasselblad or other medium format cameras. 8)
Taras