b&w conrast through colour head
Peter A H Shires
Hi - I am looking for some advice - I shoot exclusively on FP4 rated at 125
ISO and processed in Ilfosol S for the recommended time of 6 minutes with
slightly increased agitation (constant for the first 30 secs then 10 secs
per minute). I am finding that using my LPL 7700 colour enlarger and
Mulitgrade paper, that I am having to print on the equivalent of grade 4 to
get a suitable print. I can only assume that this is due to the lower
contrast found in diffuser colour heads.
My remedy would be to increase the film development times to say, 7 minutes
to compensate for this and produce higher contrast negs. Can anyone offer
any further advice, or indeed confirm this action as being the most suitable
method of curing my problem?
Many thanks - Peter Shires
Eberhard Funke
I do not know the LPL 7700. I am using a color head where I do not
have to set the M and Y individually but I just dial "grade 2" or
whatever and the color head mixes accordingly. Similar to your problem
I had to use grade 3 to get normal grade prints (densitometrically
determined, not jut feeling). So I sent the enlarger back for
reudjustment.
I recommend you get some *graded* paper and compare the results of e.
g. the fixed grade #2 from the same maker (using white light i. e. all
filters out) with the filtered grade 2 in the same developer.
If they are the same then you should increase the development time of
the film. In that case 7 mins will probably be not enough, try 9
minutes (an increase by 50 %).
If they are not the same call the maker of the enlarger.
--
Eberhard
Jerry Houston
Sounds like you have the right idea, Peter. Since you use one film
exclusively, you have the considerable advantage of being able to fine-tune
that one film so that it produces the results you want with the developer
you prefer. I've often thought I should do the same, but I'm too often
tempted by other film/developer combinations, and as a result, spend a large
part of my time experimenting.
I don't use Ilfosol S, but just as a guess, I think you might need to
develop for more like 8 minutes to make a 1-grade change. Remember that
the published times are simply starting points for your own experimentation.
The chemical content of your water, accuracy of your thermometer,
characteristics of your developing reel/tank, and your own methods can all
conspire to give you different results than the folks at the factory who did
the original experiments and published their results.
Also, your exposure metering equipment and methods may be very different
from those of the next person who uses the same film/developer combination,
again influencing your final results.
What I'd do in your situation is very carefully meter a scene with a typical
contrast range (for what you usually shoot), then expose a roll of 36
exposures all the same. Try to be sure that the lighting doesn't change
during that time, e.g., if it's a landscape, watch out for clouds moving
across the sun.
Then in the dark, cut that length of film into strips that are about 8" or
so long (double hand-width). That should give you at least 6 test strips,
each of which is long enough to handle conveniently. One at a time, load
these into a tank and process them in your normal way, and pay careful
attention to the temperature. Start at 5 minutes, and increase the
development time by 20% from one to the next. You won't need to process
them for archival permanence, or worry about dust spots, so the processing
can be somewhat haphazard, so long as the development time is exact and the
film is fixed enough to be completely cleared.
My guess is, you'll be able to find one of the negative strips that will
print just the way you want it to, and you'll develop an appreciation for
the change that a 20% increase in development makes for that film in that
developer. When you find yourself in a situation that's higher or lower in
subject contrast than your usual scene, you'll have a good idea how to
modify your development of that roll of film to make up for it.
Peter A H Shires wrote in message <6j3rgg$uo9$1...@grissom.powerup.com.au>...
<snip>
Mel1wood1
Hi - I am looking for some advice - I shoot exclusively on FP4 rated at 125
ISO and processed in Ilfosol S for the recommended time of 6 minutes with
slightly increased agitation (constant for the first 30 secs then 10 secs
per minute). I am finding that using my LPL 7700 colour enlarger and
Mulitgrade paper, that I am having to print on the equivalent of grade 4 to
get a suitable print. I can only assume that this is due to the lower
contrast found in diffuser colour heads.
My remedy would be to increase the film development times to say, 7 minutes
to compensate for this and produce higher contrast negs. Can anyone offer
any further advice, or indeed confirm this action as being the most suitable
method of curing my problem?
Many thanks - Peter Shires
I have had this problem for two years now, a color enlarger that has diachroic
or difused light os going to print a sofer image, point blank! I am in the
process of ordeing a triplecondenser B&W enlarger to fit my existing LPL
enlarger. I am just sick and tired of trying to make the color enlarger do B&W
prints.... there are times when a softer image may be an asset for a particular
imgae, but for the most part, you want your B&W's to snap! And I just simply
found my color diachroic head to be inadaquate on handling this problem,
Mel
Eberhard Funke
On Sun, 10 May 1998 09:26:31 -0700, "Jerry Houston" <jer...@oz.net>
wrote (in part):
>
>What I'd do in your situation is very carefully meter a scene with a typical
>contrast range (for what you usually shoot), then expose a roll of 36
>exposures all the same. Try to be sure that the lighting doesn't change
>during that time, e.g., if it's a landscape, watch out for clouds moving
>across the sun.
>
>Then in the dark, cut that length of film into strips that are about 8" or
>so long (double hand-width). That should give you at least 6 test strips,
>each of which is long enough to handle conveniently. One at a time, load
>these into a tank and process them in your normal way, and pay careful
>attention to the temperature. Start at 5 minutes, and increase the
>development time by 20% from one to the next.
If you develop 6 frames only then the negatives will be more contrasty
as compared to a full 36 frames film (under the same conditions, i. e.
also the same developer volume). This is because the ratio: film
surface / developer chemistry is different. This was my experience
when I first tried to calibrate my films using 10 frames development.
--
Eberhard