On Mar 18, 2005, at 10:14 AM, Tom C wrote:
I figure with an LS-9000 (assuming 4000 dpi) I should be getting 97Mp images.
At 3600ppi I get about 360Mb in 16-bit colour. Your files will be bigger than this - better upgrade your computer :)
With Photoshop CS I'd recommend at least 2Gb for files of that size. I'm running comfortably with 3.
Hmm... I was talking about the raw number of pixels scanned as opposed to file size. But thanks, good to know.
Assuming that a Pentax 6x7 negative is 58x67mm in size, a 2400 ppi scan would be 33.1 Mpixels and a 4000 ppi scan would be 91.9 Mpixels. At 3600ppi, the output data is 74.4 Mpixels.
In data size, not counting any encapsulating file information or compression, the basic data for a [EMAIL PROTECTED] RGB scan output will be [EMAIL PROTECTED], [EMAIL PROTECTED], and [EMAIL PROTECTED] per scan.
Scanning such large negatives at 4000ppi is basically a waste of time and storage space unless you're planning to make *extremely* large prints. Most printers output plateaus at around 360ppi image resolution, a very few can actually print anything larger than that. With a 4000ppi scan of a full frame 6x7 negative, that defines a 25.4x29.3 inch print area; at 3600ppi, the output is 22.8x26.4 inches; and at 2400 ppi scanning resolution, that output is 15.2x17.6 inch image area.
I scan my 645 and 6x6 negatives at 2400 ppi, the top limit on the Epson 2450, and made quite a number of excellent quality 13x19 inch prints at about 340ppi output.
Godfrey
