Digital BW, The Print

I can vouch for Doug's film holders. I use the glass carrier for most scans
and have made masks for the unusual sizes of negatives I have scanned (like
616). I have found on my V750 the optimum negative height (emulsion side) is
3.5 to 3.6mm.

 

I have the luxury of using Silverfast with the scanner and have used the
product on my other scanners since 2004 and love (have adapted) the
software. I did try VueScan but found Silverfast much more competent and
easier to use. The only issue with Silverfast is their new version 8 which I
feel is a "work in progress" and should not be considered until it can match
the flexibility of the older software.

 

Speaking of scanning with the Epson flatbed scanners, the resolution from
the scanner leaves a lot to be desired. You will find that the registration
of the color channels will be skewed vertically as the scanner makes its
pass. Resolution above 2000 dpi is very limited. I you are scanning BW and
the scanner uses only one color channel to make the scan, then the
resolution can be 3000 dpi and above. I have measured my scanner and can
achieve about 3300 dpi - which is quite satisfactory for a flat bed scanner.
Resolution was determined with a USAF target I obtained for Lasersoft.

 

Bob Rapp

 

  _____  

From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of Ernst
Dinkla
Sent: Friday, March 23, 2012 9:31 AM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: Re: [Digital BW] Re: Epson 4990 Scanner Question

 

  

On 03/23/2012 03:10 PM, faeofavalon wrote:
> Ernst,
> I will try what you said about masking it first. I neglected to mention
> the most important thing - the negatives are overexposed (simply because
> my Holga was set to "Bulb" without my knowledge!) so they are dense.
> HOWEVER, I can see through them when held up to light so the information
> is there.
>
> On another subject, yes I do scan directly onto the glass but I never
> seemed to have a focus problem. Is using the mediocre film holders that
> Epson gives me, advantageous to focus?
>
> AnnMarie

Depends, the Epson Perfection scanner models have no active focusing in 
the scanner, it is a fixed focus design and not perfect. One 4990 may 
have the focus on the glass bed, the other one 3 mm above the bed. In 
theory the best focus should be halfway the height between the film 
plane in the holders and the glass bed but the deviations are way beyond 
that. Much is compensated by the wide DOF of the lens system but there 
is something to gain there by adjusting the film holders. See this 
article written 8 years ago on the 2450 model:
http://www.normankoren.com/Tutorials/Epson_flatbeds.html

If you want to include the frame edges there is the problem that little 
film surface is left for keeping the film flat in any holder. If you 
also want to reduce Newton rings etc that would occur in using glass in 
contact with the film then there is only one solution that really keeps 
the film plane and avoids Newton rings without loss of detail etc: wet 
mounting. Doug Fisher makes custom wet mount holders and has some docs 
on how to use them, There must be something I wrote among them. Doug's 
holder has also adjustable nylon screws to get best focus. He has more 
holder types too including anti-newton glass inserts.
http://www.betterscanning.com/

-- 
Met vriendelijke groeten, Ernst

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