Reducing scan noise by scanning with a higher DPI

[Toni Nikkanen]

I use an Epson V700 flatbed scanner for medium format film. I have
found that I don't get any additional details out of my scans if I
scan over 3200 DPI. However i was thinking if it would make sense to
scan at the maximum optical resolution of 6400 DPI and then downsample
to 3200 DPI, to reduce scanning noise?

Doing that would be very disc-space consuming and somewhat cumbersome,
but I think I could make Silverfast AI Studio do it for me? If I set
DPI to 6400 and set both of the scale factors to 50%, will it write
out a 3200DPI TIFF file?

--

 

[Roger S.]

I use an Epson V700 flatbed scanner for medium format film. I have
found that I don't get any additional details out of my scans if I
scan over 3200 DPI. However i was thinking if it would make sense to
scan at the maximum optical resolution of 6400 DPI and then downsample
to 3200 DPI, to reduce scanning noise?

Doing that would be very disc-space consuming and somewhat cumbersome,
but I think I could make Silverfast AI Studio do it for me? If I set
DPI to 6400 and set both of the scale factors to 50%, will it write
out a 3200DPI TIFF file?

--

Have you tested doing this both ways and seeing for yourself if there
is a difference? I've done this with my dedicated film scanner and
yes, scanning at max optical resolution is benefitial. Please post
your findings to help others.

 

[tomm42]

I use an Epson V700 flatbed scanner for medium format film. I have
found that I don't get any additional details out of my scans if I
scan over 3200 DPI. However i was thinking if it would make sense to
scan at the maximum optical resolution of 6400 DPI and then downsample
to 3200 DPI, to reduce scanning noise?

Doing that would be very disc-space consuming and somewhat cumbersome,
but I think I could make Silverfast AI Studio do it for me? If I set
DPI to 6400 and set both of the scale factors to 50%, will it write
out a 3200DPI TIFF file?

--

I have the V700 and I think you're right 3200ppi is its max effective
resolution. Since with that res I get 400-500meg color files (6X7 and
6x9 negs), it is fine with me. Can't say if scanning at 6400ppi and
down sampling would help, I'd just get bored to tears waiting for the
scan, should take 20min or so (40 with DI). Especially with B&W I am
getting nice sharp scans. I'd be curious to see if there is any
degradation to the file at 6400ppi, but I don't have the patience to
find out. If you want to go with big prints you may get a better
result if the results at 6400ppi equal 3200ppi.

Tom

 

[Toni Nikkanen]

Especially with B&W I am getting nice sharp scans.

Yes, actually I'm very satiesfied with scan sharpness for B&W. With
color it's still good but not that good, I wonder why that is.

 

[Roger S.]

Yes, actually I'm very satiesfied with scan sharpness for B&W. With
color it's still good but not that good, I wonder why that is.

Color neg is inherently less sharp than B&W as it has multiple light-
sensitive layers.

 

[Toni Nikkanen]

Color neg is inherently less sharp than B&W as it has multiple light-
sensitive layers.

Maybe so, but if I compare 35mm color neg (or positive, I have both)
or B&W on my K-M Scan Elite 5400II, I get very good sharpness out of
both and have no reason to complain.

I notice significant difference in sharpness between color and B&W
only on the Epson flatbed. Maybe the flatbed just exaggerates this
difference in film sharpness or whatever, I don't know.