Digital BW, The Print

B & Roger,

OK, I accept the slap-on-the-wrist for using imprecise terminology. So 
whether the three-quarters of the data that are thrown away contain detail, 
obviously depends on the image. Some will, some won't. But it doesn't change 
the fact that AFAIK most scanner software simply throws away or ignores the 
excess sample points. In which case, why use a large format film if you are 
going to ignore three-quarters of the data on it? A film format one-quarter 
of the size would give better results.

I seem to remember Vuescan scanner software does allow for scanning at 
optical resolution and averaging the data points to produce a smaller file.

Bob Frost.

----- Original Message ----- 
From: "Roger Howard" <rogerhoward@...>

I think in this context you should interpret the previous posters use
of the term "detail" as really to mean "data". Your analysis is correct
on the whole, when taking a less mathematical definition of detail - if
you simply mean the visible details of a particular image, then of
course it varies from image to image, and you may well not lose 3/4's
of the detail by sacrificing 3/4's of the scanning resolution - you
will loose 3/4's of the scanned data however. This distinction between
significant visual detail and the much more literal "data" needs to be
kept pretty clear... scanning at twice the resolution will often not
give you four the detail, just four times the data.