Digital BW, The Print

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.  It has taken some experimentation on my
Polaroid SS4000 and Artixscan 1800 to get top sharpness scans. The heat from
the scanning bulb causes small amounts of movement of the film.  I noticed
this when scanning glass plates, which were substantially sharper than my
film scans.  Then I recalled why fine art printers use only the Focomat 1C
for 35mm.  My experience with that was once a photographer gave me a grainy
neg to print and supplied me with a match print.  I could not duplicate the
result using my D2, either with a cold light head or condenser head, because
the grain in his match print was perfect and my print was a hair soft.  I
asked my friends for advice, and the curator of photography asked me:"Do you
know the difference between the best enlarger in the world and the worst?"
well yes I said, "there is that much difference again between the best and
the Focomat."  I polled all the fine art printers I knew and got basically
the same story.  I bought a Focomat at once, and here is what I learned:
the design of the negative stage is what makes the difference.  The Focomat
negative carrier is what we would consider to be only the bottom part of
one.  In the Focomat, the condenser itself sits directly on top of the
negative.  As the bulb heats, it is impossible for the film to move at all.
The result is tack sharp grain from corner to corner.

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.

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)

Tom Robinson

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