I just got an Epson 3170 and will be using it to archive thousands of old
slides (30+ years old). I'm deciding whether to use 24 or 48 bits. My limited
research indicates that scanning at 48 bits provides only a marginal benefit vs
24 bits, and it would apply mainly to images that need significant adjustment
due to poor exposure, fading or deterioration.

In the Epson Scan software, the 24 or 48 bit settings indicates that this
applies to the "destination" (it apparently does not give the option of setting
input and output separately). If the 24 bit setting is selected, I'm wondering
if it scans at 48 bits and saves as 24 bits? How does the color restoration
feature work? Does it adjust levels and curves automatically at 48 bits during
the scan and then Epson Scan saves the result as a 24 bit file? If this is the
case, it seems like a waste of time to scan and save at 48 bits, then perform
adjustments manually in Photoshop. Opinions? Thanks.

On 11 Oct 2003 18:29:55 GMT, sb083459@aol.com (Sb083459) wrote:

The 3170 can also output in 48 bit mode. A 3200 dpi scan will be 64
MB vs 31 MB in 24 bit mode. Photoshop 7 supports 48 (or 16 bit per
channel) bit editing, but you will have to convert it to 24 bit

I own a 3170 and I use "Professional Mode" in my Epson Scan 3170
before scanning in to Photoshop in 24-bit mode.

Under Professional mode you see a series of buttons underneath
"adjustments". The third button from the left will bring up a curves
tool. In your preview, select the slide you wish to work with with
the blue frame, then click on the "full size" tab so you will have a
larger preview so you can see the effect of the curves tool.

I like it. It will keep the setting for that particular slide or
negative. You can save the new setting under another name in case you
want it on all your slides.

I've scanned it into PS 7 and I like the results. I have a smooth
histogram and there is little need to go to high-bit scans.

Of course you can experiment.

Gene--