> > Basically the new 4000 dpi m/f scanners will output such large files
> that
> > handling them demands a new ball game in desktop systems: files of 500
> to
> > 700 Mb will be common at 4000 dpi, (in 16bit), and no doubt 6000 dpi
> will
> > come along soon for 35mm. If you do 5x4" - god help you.
>
> I think it comes down to what resolution you need for the intended
> purpose. I
> think 300 ppi for an 8 X 10 is sufficient for my Epson 1200 printer (2400
> X 3000
> image size). I can not discern any improvement with higher resolutions -
> not
> that I would turn down a 4000 or 6000 ppi scanner if I could afford it and
> I do
> work with image files much larger than this.
>
But 2 1/4 inches times 4,000 ppi should create a 37.6 inch print at 240 ppi.
Just about perfect for an Epson 9500 printer. Someone shooting medium
format and contemplating this type of system may very well be interested in
this size prints. Even if smaller images are desired, it is best to scan at
full resolution and later reduce the size in Photoshop.
> >
> >
> > Processing power is not the problem, a high end Mac, P4 or AMD Athlon,
> will
> > all do the job well. All of these have enough power/ MHz. The issue
> seems to
> > be the memory handling of these large files:
> >
> > Now, the rule of thumb is that you need 3 to 5 times the RAM as your
> file
> > size for efficient PS handling, so... this means maximum RAM on the
> machine:
>
I have worked with files that are 16k by 16k, B&W, 16 bits per pixel,512 MB
file size with no problem. Slow to open (80 sec), even slower to save(200
sec), but quite usable(an unsharp mask took 90 seconds). This is on a stock
G4/500 running Photoshop 5.0.2 (no altiVec support) with just 256 MB of real
memory and lots of other applications running and a fragmented, nearly full
disk (512 MB file written into 124 fragments!). Everything was limited by
disk access.
Anybody know what the image size limits might be for Photoshop under the
various operating systems? Photoshop itself limits the dimensions (
) to be less than 30,000
pixels and 417 inches. A related page (
) seems to indicate that
Windows may have a limit of 1GB per file (95, 98, and or 2000? also this
may be a limitation of the MCI/Video player) and that the Mac has a
limitation of 2GB per file.
