Digital BW, The Print

On 21/5/03 7:35 pm, "Tom Robinson"
<DigitalBlackandWhiteThePrint@yahoogroups.com> wrote:

> 
> THIS POST IS ABOUT IMPROVED SHARPNESS IN SCANNING AND ENLARGING.
> 
> I must say that I think every flatbed and slide scanner that I have used is
> making less than optimum sharpness scans of film due to the design of the
> negative (or slide) holders.

Couldn't agree more - you may also find Newton's ring artefacts where the
tranny touches the flatbed glass and reflections of the curved film held
imperfectly in the film holder - at least that's been my experience with
Epson.
> 
> Applying this to slide scanners, I took the anti-newton glass out of a
> german slide mount, and mount it in the scanner neg carrier on the top of
> the film only, then close it.  ASTONISHING IMPROVEMENT in FOCUS and
> SHARPNESS -- MUST BE SEEN TO BE APPRECIATED.
> 
> As to flatbeds, don't think the trannie hood is going to flatten the film,
> it does not even begin to.  Put a piece of glass over your film before
> closing the trannie hood.

My thinking and practice exactly BUT some scanner seem to focus slightly
above the plane of the flatbed glass but seem to have adequate depth of
field to cope. However the texture of some anti-Newton glasses can be picked
up as well as their 'colour'. I've tried a Durst COSIGLAS 6x9 AN glass which
has no surface texture problems but has a distinct blue-green cast and cuts
out a surprising amount of light from the tranny hood.

> If someone is measuring film enlarging quality with a D2 or Beseler or
> scanner with open film carriers, they are not going to get any idea of what
> they could have (although any of these can be easily modified as above, and
> I recommend it)

The best scanner negative carrier I've seen is on the Imacon Flextight
scanner - I believe UMax make a similar thin metal/magnet sandwich which
could address the scanner focus issue too. Any one here tried one?
--
David Prakel

Centre of Britain PhotoWorkshops Partnership
www.photopartners.co.uk