Epson 4870 goes blurry with multi-pass

[retoricus2]

Hi guys,

I bought my Epson 4870 in August 2004 after seeking advice in this
forum. I use Vuescan 8.1.20 on an iMac with Os X 10.3 I was warned
that 16x multisampling, which I wanted to use when scanning old black &
white prints for restoration, could be a problem on any scanner that
used multi-pass instead of single-pass multisampling.

I tested the 4870 when I had bought it and the multi-pass function was
accurate, there was no misalignment between passes. Multisampling gave
the extra clarity and crispness that it should. I was happy with my
purchase. But now I noticed scans getting soft and I tested it again,
alarmingly the scans are blurry at 1200 when using 16x and even worse
at 2400. Now only single-pass scans give acceptable sharpness. How
depressing! I can only guess that the wear and tear the last few months
(I have used the scanner a lot) has introduced slack in the mechanical
parts of the scanner....

I may have to sell the 4870 to someone who doesn't need 16x (most
people never heard of multisampling anyway) and get something else.
Epson doesn't advertise multisampling for 4870, this is a feature made
possible when using Vuescan, so complaining to Epson is probably
pointless.

Is there ANY way to trick the 4870 into making single-pass 16x
multisampling?
If not, is there any other affordable flatbed scanner (Epson 3200?)
that can do 16x standing-still multisampling?
..
VB

 

[-]

With your heavy use, I bet you are right about slack in the drive train. At
the same time, you might want to go back and try an older version of Vuescan
to make sure there isn't any issue with it. You are probably one of the few
people using this feature with a 4870, so you are the beta tester . There
have been reports of problems with the alignment of the IR comparison layer.
If this is a true problem, any changes made to correct that might have
affected your situation. People have seen other instances when fixing one
problem caused others to crop up. Just a thought.

Doug
---
Doug's "MF Film Holder" for batch scanning "strips" of 120/220 medium format
film:
http://home.earthlink.net/~dougfisher/holder/mainintro.html

<[email protected]>

 

[retoricus2]

Hi Doug

Trying an older version of Vuescan is a good idea. I went back to
7.6.79... is that old enough re the IR problem? With 7.6.79 the blur is
the same, single-pass is sharper than multi-pass.

Does multi-sampling matter? To be fair to Epson, the 4870 is better
with a single sample than my old 1260 was with multi-sampling! The 4870
doesn't have much electronic noise. Still, when I want the best
possible scan 16x is the way to go. Yes, I CAN see the difference.

On a side note, if I change scanner I don't need film scanning
capabilities from a flatbed scanner. I have a Minolta Multi Pro for
that.
..
VB