RE: filmscanners: File sizes, file formats, etc. for printing 8.5 x 11and 13 x 17...

["shAf" <michael@shaffer.net>]

Marvin writes ...

> I am confused as to the techniques that are used.
> I had the pleasure of viewing a CD of b & w TIFF
> scans this past weekend, made by a professional
> photographer, who is at the level that he has had
> photographs published by National Geographic.
> He told me he had scanned the 35mm b & w
> negatives at 2700 dpi.
> Using PS, I found that the file sizes were about
> 5MB, the print sizes were about 5 x 7
> and the ppi were 385.

        Whereas I thought this photographer's prints would provide an example
of the math, it doesn't work.

        1st ... scanning at 2700ppi simply implies he scanned his film at the
scanner's maximum, he later redefined it print size and resolution
with Photoshop (as Austin suggested).

        2nd ... the 385ppi setting you mention is probably specific to the
printer he used.  That is, after trails and tribulation, he came up
with 385ppi being the best res to send to the printer, and defined it
as such using PS's 'image size' dialog.  (It is a rather high res, but
who is going to argue with a photographer accepted by NG, and who know
what printer he used???)


        However, the math does not agree with the filesize you mention!!

        (5" X 385ppi) X (7" X 385ppi) X 3 RGB channels is not equal to 5Mb!!
... more rather, ~15Mb (no wonder you are confused???)

shAf  :o)