LPL 7700 Enlarger question

My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?

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On Tue, 5 Oct 2004 22:47:24 +0800, "Steve Marshall"
wrote:

My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?

Have you tried changing the bulb ? Bulbs shift toward yellow
as they age. If your using VC (something I don't recommend) then the
light could be yellow enough to drop the contrast.

If this has already been dismissed then I suggest you redefine
the term muddy which generally is used to indicate a lack of contrast
(tonal separation).


Regards,

John S. Douglas, Photographer - http://www.puresilver.org
Please remove the "_" when replying via email

Steve Marshall wrote:
My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?



Have they tried no filters? If that works okay and it should give you
basically grade 2 then check other things. What happens when you dial in max
magenta? Are you using a known good lens?

Nick

Steve Marshall wrote:
My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?



Have they tried no filters? If that works okay and it should give you
basically grade 2 then check other things. What happens when you dial in max
magenta? Are you using a known good lens?

Nick

"Steve Marshall" wrote in message ...
My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?


Hi Steve
First thing, take a piece of unexposed, and a piece of paper exposed
to room light & develop them. If one comes out black, & one white,
then U should know that the paper & chems. are ok.
If U are using variable contrast paper, try using a graded paper, and
also try using a VC paper w/o filtration. Those are best guesses, not
knowing what U are doing or have tried. If either of the last two
work, U should have a pretty good idea that the problem is somewhere
in the color of the dichro. head.

Hope this might help, John

Steve Marshall wrote:
My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?

I've been taking a photo course where the school has LPL colour
enlargers (probably cheaper models than yours but the principle
should be the same.) I found that the nominal grades (based on
the colour settings listed on the sheet which came with the paper)
are around 1 1/2 grades softer than my Meopta Magnifax condenser
enlarger with Ilford filters.

I would suggest looking at the colour settings listed on the
sheet that comes with your VC paper or on the manufacturer's
website and starting off with the settings listed for grade
3 1/2 or 4. I did a print at grade 4.5 which I would have
printed at grade 3 at home, and it produced a nice full range
of gradations in spite of the nominally high paper grade.

Peter.
--

Some years ago in a local high school darkroom where I was doing a
little coaching, I had a similar situation. It seemed unlikely but in
very short order multiple machines behaved this way and it turned out
to be fogged lenses. Something must have occurred that triggered this
and I never really figured out the exact cause but it turned out to be
the enlarging lenses. A few months before, in a class given in the
prior semester, they were fine. They didn't seem all that bad under
casual inspection but the flare really degraded the image contrast.

You mention B&W prints.... Are you saying that it was working okay on
color? Not sure how to read that....

On Tue, 5 Oct 2004 22:47:24 +0800, "Steve Marshall"
wrote:

My camera club has an LPL C7700 Pro Colour System enlarger. Recent attempts
to make b&w prints on it have resulted in very unsatisfactory muddy prints,
from negs wihich print fine on another enlarger. The users have used a few
different recommended settings for the colour filters, but nothing seems to
improve the results.

Anyone have any idea what the problem might be?


Craig Schroeder
craig nospam craigschroeder com

-Eschew Obfuscation-

"Craig Schroeder" wrote

fogged lenses. Something must have occurred that triggered this
and I never really figured out the exact cause but it turned out to be
the enlarging lenses. A few months before, in a class given in the
prior semester, they were fine.

I lay odds the maintenance did something involving solvents during the
inter-semester break. Painting is the usual culprit - that haze that's
on the lenses is on everything else too...

It is not uncommon for electronics to get flakey after painting: the
organics get into the micro-holes in gold plating. The gold works
like a zeolite polymerizing the organic compounds. Soon the
switch/contact becomes noisy, intermittent or stops working all together.


--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

Thanks everyone for this very good feedback. I am personally not a darkroom
buff, and asked the question on behalf of others. I am passing all the
responses on, in the hope they will achieve the desired result.

For someone who asked if the enlarger works OK for colour - well, we don't
really know, as the members who want to use it are only interested in b&w
(at this stage anyway). I have the impression it is quite a while since this
enlarger was last used.

Thanks again

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"Steve Marshall" wrote in message
...
My camera club has an LPL C7700 Pro Colour System enlarger. Recent
attempts to make b&w prints on it have resulted in very unsatisfactory
muddy prints, from negs wihich print fine on another enlarger. The users
have used a few different recommended settings for the colour filters, but
nothing seems to improve the results.

Anyone have any idea what the problem might be?

--
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www.marshallarts.com.au

On Wed, 06 Oct 2004 02:22:01 GMT, "Nicholas O. Lindan"
wrote:

I lay odds the maintenance did something involving solvents during the
inter-semester break. Painting is the usual culprit - that haze that's
on the lenses is on everything else too...

Or perhaps it could have affected the cement in the lenses.


Regards,

John S. Douglas, Photographer - http://www.puresilver.org
Please remove the "_" when replying via email