Vuescan 4870 Batch and Multipass

M

MW

Hi, does Vuescan support batch scanning with the Epson 4870? I can't
see that it does.

How about multipass? I tried the scan to file and wanted to see if
multipass scanning from the raw file would result in better shadow
detail. Any comment?

Thanks,
Matt
 
E

Erik Krause

MW said:
How about multipass? I tried the scan to file and wanted to see if
multipass scanning from the raw file would result in better shadow
detail. Any comment?

You can no multi pass scan from raw. The noise is already present in
the raw file.

The noise reduction with multi scanning is baesed on the fact that
noise is different in each scan. This requieres physical scans.
 
D

Don

You can no multi pass scan from raw. The noise is already present in
the raw file.

The noise reduction with multi scanning is baesed on the fact that
noise is different in each scan. This requieres physical scans.

But his alignment will be perfect... ;o)

Seriously though, one cautionary note: *Multi-pass* multi-scanning in
VueScan is just a very time consuming and complicated way to blur an
image - and still manage to preserve most, if not all, of the noise!

The only way to get any meaningful noise reduction with multi-pass
multi-scanning is to *sub-pixel* align each image before averaging
them out. And even then the sub-pixel alignment will introduce slight
blurring so many more scans would be needed to achieve a comparable
effect to a smaller number of true single-pass multi-scans.

Don.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top