Agfa MCP RC paper contrast

"sreenath" wrote in message
...
Hi, I have been using this paper (11X14) with Ilford
filters.

I don't know if I am sufficiently developing films, but
prints have
low contract.

Do Ilford filters allow all possible contract with this
paper? For
example, does Ilford Grade 4 filter really give grade 4
results with
Agfa paper?

thanks,
Sreenath

Is this genuine old stock AGFA paper? If it is the
paper has probably lost some contrast. If its some current
clone then the manufacturer should be contacted about what
filters to use. Sometimes, if there is a chart for setting a
color head you can tell whether the paper is designed for
Kodak or Ilford filters. The two are not the same. While one
can be used for the other paper the grade steps and the
exposure compensation will not be the same.
If you have access to a step wedge and reflection
densitometer you can measure the contrast. Otherwise its
guesswork. Even without the densitometer you can get a
pretty good idea of the contrast visually since the step
wedge has more steps than the paper will reproduce. Stauffer
makes good step wedges, the uncalibrated ones are not very
expensive. Actually a Kodak Projection Print Scale, while
not at all a precision device, can give you a good idea of
contrast via visual measurement.
Note the developer can make a little difference. Try
Dektol at 1:1 rather than 1:2 or the equivalent with another
developer to see if it makes any difference.
Testing with known negatives will also help since you
will then isolate the problem to the paper and not the
negatives.
My experience with AGFA paper when it was still in
production by AGFA was that it worked with both Kodak and
Ilford filters although I mostly used Kodak ones. It was one
of my favorite papers and I never had problems with lack of
contrast or poor blacks. Current stuff may or may not be the
same regardless of the name on it.


--
Richard Knoppow
Los Angeles
WB6KBL

"sreenath" wrote in message
...
On Dec 11, 7:40 am, "Richard Knoppow"
wrote:
"sreenath" wrote in message

...

Hi, I have been using this paper (11X14) with Ilford
filters.

I don't know if I am sufficiently developing films, but
prints have
low contract.

Do Ilford filters allow all possible contract with this
paper? For
example, does Ilford Grade 4 filter really give grade 4
results with
Agfa paper?

thanks,
Sreenath

Is this genuine old stock AGFA paper? If it is the
paper has probably lost some contrast. If its some
current
clone then the manufacturer should be contacted about
what
filters to use. Sometimes, if there is a chart for
setting a
color head you can tell whether the paper is designed for
Kodak or Ilford filters. The two are not the same. While
one
can be used for the other paper the grade steps and the
exposure compensation will not be the same.
If you have access to a step wedge and reflection
densitometer you can measure the contrast. Otherwise its
guesswork. Even without the densitometer you can get a
pretty good idea of the contrast visually since the step
wedge has more steps than the paper will reproduce.
Stauffer
makes good step wedges, the uncalibrated ones are not
very
expensive. Actually a Kodak Projection Print Scale, while
not at all a precision device, can give you a good idea
of
contrast via visual measurement.
Note the developer can make a little difference. Try
Dektol at 1:1 rather than 1:2 or the equivalent with
another
developer to see if it makes any difference.
Testing with known negatives will also help since
you
will then isolate the problem to the paper and not the
negatives.
My experience with AGFA paper when it was still in
production by AGFA was that it worked with both Kodak and
Ilford filters although I mostly used Kodak ones. It was
one
of my favorite papers and I never had problems with lack
of
contrast or poor blacks. Current stuff may or may not be
the
same regardless of the name on it.

--
Richard Knoppow
Los Angeles
WB6KBL


Hi,

The paper came in plain unmarked box, but I think this is
the original
Agfa paper, bought on eBay a few years ago. I bought 250
sheets of
11X14 and like the paper very much.

Since I don't have access to step wedge or densitometers,
I cant
really check the negatives. The problem is also compounded
by the fact
that developers are no longer available commercially in
India. I mix
my own and its activity is also a suspect.

How much contrast does paper lose over time?
I will try a stronger print developer (I use ID-62 at 1+3
which is the
recommended dilution)

thanks for the help,
Sreenath

The loss of contrast varies a lot among papers.
Variable contrast papers do not seen to have as long a shelf
life as graded ones. I found that old Kodak VC paper lost
contrast faster than either AGFA or Ilford but, unless the
paper has been stored frozen, its going to suffer chemical
changes that will lower its contrast and make it foggy.
You may be able to get some idea of the contrast by
making stepped exposures, the same as you would for testing
for correct exposure. You can get the equivalent of a step
wedge using this method but the step wedge eliminates errors
in f/stop from the lens or reciprocity failure effects from
changing exposure time. Nonetheless, reciprocity errors
should be small within normal exposure times and is more
likely to give you errors than relying on the f/stop
calibration of the lens. Paper grades are established as ISO
standards and the information is often included in the paper
data sheet. In any case, since there is a standard each
grade should be the same among different papers. You should
be able to tell if there is a major error this way.
I think using the "wrong" set of filters can create as
much as a one paper grade error in mid-grades but the
greatest errors are usually at the ends of the range. So if
you are going for grades around 1 to 3 the wrong filters
should not introduce a large error. If the filters work OK
with other papers the chances are that the paper has just
gotten old. If it still makes good prints when a suitable
filter is used you may just have to compensate for it by
experimenting.
BTW, I used to get AGFA paper in white boxes from
Freestyle. I knew it was AGFA from the odor! AGFA always had
a characteristic, distinctive smell, even years ago when it
was sold as Ansco paper here. Of course the surface texture
is also a tip off.
Let me know what you find.


--
Richard Knoppow
Los Angeles
WB6KBL

On 12/11/2010 10:17 AM Richard Knoppow spake thus:

[...] Nonetheless, reciprocity errors should be small within normal
exposure times and is more likely to give you errors than relying on
the f/stop calibration of the lens.

I think you meant to write "is *less* likely to give you errors ..."
here? (IOW, more accurate to change exposure times rather than f-stops.)


--
Comment on quaint Usenet customs, from Usenet:

To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.

"David Nebenzahl" wrote in message
.com...
On 12/11/2010 10:17 AM Richard Knoppow spake thus:

[...] Nonetheless, reciprocity errors should be small
within normal
exposure times and is more likely to give you errors than
relying on
the f/stop calibration of the lens.

I think you meant to write "is *less* likely to give you
errors ..." here? (IOW, more accurate to change exposure
times rather than f-stops.)


Yes, that's what I meant, somehow it got lost in the
way to my fingers.


--
Richard Knoppow
Los Angeles, CA, USA

On 12/14/2010 11:19 AM, sreenath wrote:


Another problem I have is enlarger lamps. They are no longer available
here, and I am using a Philips ""Cool tone" lamp, which is creamish,
instead of white. They have done this by giving a special coating to
make the light to look warm (cool tone!) I suspect it is cutting
blue light causing drop in contract also.

I will experiment with a magenta paper on the condenser to compensate
for the "cool tone" light bulb.


The bulb likely has as much or more to do with this than the filters or
the old paper. The color temp of the bulb can have a huge effect on all
this.

Stephey

wrote:
The bulb likely has as much or more to do with this than the filters or
the old paper. The color temp of the bulb can have a huge effect on all
this.

I used to have a Phillips enlarger that had separate red, green and blue
lights (I think they were regular 12v halogen bulbs with filters) and
a controller that allowed you to set the time for each color.

I wonder if you could make an array of LEDs do the same thing? I guess the hard
part would be to get LEDs that had the correct colors to activate the
appropriate layers in the paper.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Those who cannot remember the past are condemned to misquote it.

"sreenath" wrote in message
...
On Dec 14, 11:29 am, "Richard Knoppow"
wrote:
"David Nebenzahl" wrote in
message

.com...
On 12/11/2010 10:17 AM Richard Knoppow spake thus:

[...] Nonetheless, reciprocity errors should be small
within normal
exposure times and is more likely to give you errors
than
relying on
the f/stop calibration of the lens.

I think you meant to write "is *less* likely to give
you
errors ..." here? (IOW, more accurate to change
exposure
times rather than f-stops.)

Yes, that's what I meant, somehow it got lost in the
way to my fingers.

--
Richard Knoppow
Los Angeles, CA, USA


Actually, I am forced to use grade 4 filer routinely. So
the grade
error may be large as you have indicated.

Another problem I have is enlarger lamps. They are no
longer available
here, and I am using a Philips ""Cool tone" lamp, which is
creamish,
instead of white. They have done this by giving a special
coating to
make the light to look warm (cool tone!) I suspect it is
cutting
blue light causing drop in contract also.

I will experiment with a magenta paper on the condenser to
compensate
for the "cool tone" light bulb.

-Sreenath

You didn't say this was a cold light enlarger. If it is
beware that the spectral output of flourescent lamps is
quite different from incandescent lamps even when they
_look_ the same. The paper and filters are made for
incandescent lamps of a color temperature around 3K. Nearly
all standard enlarger lamps will be close. If a cold light
lamp is used some compensation must be applied in the form
of additional filters. Even with the compensating filters
the grade spacing and range will usually not match that for
incandescent lamps. The data sheets for Ilford and older
Kodak products (which may still be available) have some
suggestions about the compensating filters. Even color head
enlargers will not usually give you the full range of
contrasts available from an incandescent lamp and regular
filters although one can get reasonably close contrast and
exposure matching over at least the center of the range.
Probably your problems are coming from the light source and
not the paper or filters.


--

--
Richard Knoppow
Los Angeles
WB6KBL

"sreenath" wrote in message
...
On Dec 16, 2:15 am, "Richard Knoppow"
wrote:
"sreenath" wrote in message

...



On Dec 14, 11:29 am, "Richard Knoppow"
wrote:
"David Nebenzahl" wrote in
message

rs.com...
On 12/11/2010 10:17 AM Richard Knoppow spake thus:

[...] Nonetheless, reciprocity errors should be
small
within normal
exposure times and is more likely to give you
errors
than
relying on
the f/stop calibration of the lens.

I think you meant to write "is *less* likely to give
you
errors ..." here? (IOW, more accurate to change
exposure
times rather than f-stops.)

Yes, that's what I meant, somehow it got lost in
the
way to my fingers.

--
Richard Knoppow
Los Angeles, CA, USA


Actually, I am forced to use grade 4 filer routinely.
So
the grade
error may be large as you have indicated.

Another problem I have is enlarger lamps. They are no
longer available
here, and I am using a Philips ""Cool tone" lamp, which
is
creamish,
instead of white. They have done this by giving a
special
coating to
make the light to look warm (cool tone!) I suspect it
is
cutting
blue light causing drop in contract also.

I will experiment with a magenta paper on the condenser
to
compensate
for the "cool tone" light bulb.

-Sreenath

You didn't say this was a cold light enlarger. If it
is
beware that the spectral output of flourescent lamps is
quite different from incandescent lamps even when they
_look_ the same. The paper and filters are made for
incandescent lamps of a color temperature around 3K.
Nearly
all standard enlarger lamps will be close. If a cold
light
lamp is used some compensation must be applied in the
form
of additional filters. Even with the compensating filters
the grade spacing and range will usually not match that
for
incandescent lamps. The data sheets for Ilford and older
Kodak products (which may still be available) have some
suggestions about the compensating filters. Even color
head
enlargers will not usually give you the full range of
contrasts available from an incandescent lamp and regular
filters although one can get reasonably close contrast
and
exposure matching over at least the center of the range.
Probably your problems are coming from the light source
and
not the paper or filters.

--

--
Richard Knoppow
Los Angeles
WB6KBL


My enlarger lamp is incandescent lamp - frosted type (We
cal it
"milky" here). The coating given inside the bulb is
creamish, not pure
white as regular milky bulbs are. Philips calls them
"cool" easy on
the eyes, because they wont look bluish.

I seem to have several problems with respect to light
source, and
perhaps the filters are really not to blame.
I am considering LEDs as a source of light in enlarger,
but building
one is a way off.

thanks for all the insight,
Sreenath

The original enlarging lamps were coated with a highly
diffusing material, much more diffusing than normal
"frosted" household lighting lamps. These are called "opal"
lamps because the coating looks similar to true opal glass.
Normal houshold lamps are not diffuse enough to give uniform
illumination with most enlargers. Plus, most have the brand
name stamped on the end of the bulb so that when used in a
condenser enlarger it can be imaged on the print. Opal lamps
are getting hard to find. I think Freestyle in Los Angeles
still has some common size ones. I don't know if its
economical to obtain them where you are but if so I suggest
using them rather than some substitute.
I think LED's do not have a uniform spectrum. Probably
there is information on the web about this. Flourescent
lamps use phosphores for most of their output so the
spectrum is broken. While it may visually resemble
incandescent light or daylight it does not have the same
spectrum and may not react photographically in the same way
as visually similar light from a source with a continuous
spectrum like an incandescent lamp or sunlight.


--
--
Richard Knoppow
Los Angeles, CA, USA

On 12/16/2010 9:40 AM Richard Knoppow spake thus:

The original enlarging lamps were coated with a highly
diffusing material, much more diffusing than normal
"frosted" household lighting lamps. These are called "opal"
lamps because the coating looks similar to true opal glass.
Normal houshold lamps are not diffuse enough to give uniform
illumination with most enlargers. Plus, most have the brand
name stamped on the end of the bulb so that when used in a
condenser enlarger it can be imaged on the print. Opal lamps
are getting hard to find. I think Freestyle in Los Angeles
still has some common size ones.

Try Don's Bulbs: http://www.donsbulbs.com/cgi-bin/r/t.pl

(hint: enter the manufacturer of your enlarger in the field marked
"equipment search")


--
Comment on quaint Usenet customs, from Usenet:

To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.

On 12/16/2010 7:05 PM David Nebenzahl spake thus:

Try Don's Bulbs: http://www.donsbulbs.com/cgi-bin/r/t.pl

(hint: enter the manufacturer of your enlarger in the field marked
"equipment search")

Just a warning; Don's bulbs are not cheap.
F'rinstance, here's an enlarger bulb--for $28 (15 in stock):

http://www.donsbulbs.com/cgi-bin/r/b.pl/i|120v|75w|e26|s14|white|50h%5Eph140~ansi.html


--
Comment on quaint Usenet customs, from Usenet:

To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.