Kodak Polycontrast filters

Hi all !
I got a Kodak Polycontrast filter kit ( model A )
It's an older one, under the lens 7 filters kit.
Anybody knows if exposure compensation is needed
for different grades ? I was told that there was some
kind of "exposure calculator" for this kit, but
unfortunately I can't find it.
Thanks,

 

Yes, there was. Write to Kodak, in case that thought didn't cross your
mind.

 

yes compensation is required. I don't use a calculator - I do test strips
for each contrast grade change. Bit I looked in my Kodak B&W dataguide
sixth edition, copyright 2001 and found on page 48 the following:

"There is no change in effective paper speed within the range -1 to 3 1/2
and within the range 4 to 5+. You need to recalculate exposure when you
switch from one range to the other, or when you remove the filter completely
or add a filter when you have been printing without one."

The explnation then goes on to describe how to set the calculator (page 49).
I'll give you an example to show the factors:

If the "no filter" print time is 10 seconds, then the "-1 to 3 1/2" range is
20 seconds and the "4 to 5+" range is about 41-42 seconds.

Thus for going from no filter to a "-1 to 3 1/2" doubles the time.
Going from no filter to a "4 to 5+" increases the time by a factor of
slightly more than 4.

Going from a "-1 to 3 1/2" to a "4 to 5+" will about double the time (20
seconds to 42 seconds, for example)

This calculation seems constant. The same multipliers apply to all paper
speeds, chemicals, etc (or at least there is no compensation on the
calculator dial for anything but filer grade changes).

Hope this is helpful.

 

This is for the NEW set. The old set was different, and each filter
required a different factor.

You need the calculator.

 

Yes, it's an older one. And yes, I'm afraid that I need
the calculator. The problem is that I don't know where
to get one..
Thanks,

 

Write to or call Kodak. They'll be glad to help you!

 

Sorry - you are right - the title says "When you change from one Polymax
filter to another:" I don't have anything relating to the older filter
sets. I have one that is about 30 years old and has 5 filters, but I don't
use it - it's on the "museum" shelf.

 

Looking at the calculator in an old databook, listed below are the
adjustment factors, which you could use to set up your own calculator.
As an example, if you expose the first print with white light at 10
seconds, the following would be the time for various filters:

White - 10 seconds
1 - 15 "
1-1/2 - 15 "
2 - 14 "
2-1/2 - 16 "
3 - 20 "
3-1/2 - 25 "
4 - 50 "

If a filter was used for the first exposure, then the times would be
appropriately adjusted based on the above relationships.

The notes state that the above are for a tungsten light source. They
also recommend opening up the lens if exposures exceed 60 seconds.

 

Thanks a lot to all !
Best wishes,

 

Polycontrast filter sets requires exposure compensation for each change in
filter, PC II and III sets require less compensation from filter to filter
but changes are still required. The calculator will get you close but
testing is still necessary.