Filter grades

Nick Zentena wrote:

Need a green and a blue.


Won't yellow and magenta do?
I've checked a few Ilford MG paper characteristic curves.
Over all the lines do not indicate grade untill densities above
1 to 1.5 have been reached. Below those densities grade
lines merge. In effect, for half or more of their density
range those MG papers are little more than a single
grade paper. I was surprised at seeing that.
No wonder split filtration is used so and to the extreme.
Ilford's MG is in contrast with their Graded Galerie paper.
Each Grade's curve is distinct from one another toe to shoulder.
The grade is in the paper, no splits needed. Dan

wrote:
Nick Zentena wrote:

Need a green and a blue.


Won't yellow and magenta do?

Yup. I just don't know which ones-) You'd have to look at the curves on
the Rosco website to see which ones would work best.

Nick

--
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"Digital the new ice fishing"
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Nick Zentena wrote:

Wai-Ming Ho wrote:

Before running out to order the step wedge, I like to know what is used
to measure the wedge density. In case it needs a densitometer that I
don't have.


You might want to run out and get Anchell's book "The Variable Contrast
Printing Manual". He has a chapter on calibrating grades. Basically stick
the wedge in the enlarger. Make a print. Count the number of steps that are
neither pure paper white or pure black. Compare that number to the chart and
you get a grade. It's a bit more complicated then that but not much more.


Will definitely do that. Just need to move the book from the wait list
into the order basket...



I was thinking of spreading the "wear" of my filters instead of just
using the 0 and 5. If the cost of the wedge outweighs changing a whole
filter pack just for a new set of 0 and 5, I would stay with split
filtering...


Just get a couple of sheets of lighting gels made by Rosco. 20"x24" they
cost about $6 each and will work fine for spilt filtering. Need a green and
a blue. Or put the money towards a colour head.


Thanks, will look into that.

waiming

Nicholas O. Lindan wrote:

"Wai-Ming Ho" wrote

Or perhaps I need to have a reference wedge output
for each filter grade at the specified enlarger height, dev time and temp.


Yes. A series of 12 exposures will do it. I do four 4x5" exposures
on an 8x10 sheet, shift the sheet between exposures. Process all three
8x10 sheets together.

You may want to find someone to measure the test print densities.
It can be quite a revelation: the 'curves' aren't as shown in the
books: lumps and bumps; and many filters make no difference from the
filter next to them [2 1/2 == 2 is common].



Thanks for the explanation.

waiming

Gregory Blank wrote:

In article ,
Wai-Ming Ho wrote:



I was thinking of spreading the "wear" of my filters instead of just
using the 0 and 5. If the cost of the wedge outweighs changing a whole
filter pack just for a new set of 0 and 5, I would stay with split
filtering...


Well, to me the most important consideration is wether you can get
the contrast you desire, realizing that contrast adjustment is separate
from exposure.


Thanks for highlighting that. My prints have been staring back at me
trying to tell me just that but I wasn't getting it then :-)

waiming

Thanks. for the tip.

waiming

UC wrote:

You first need to use some graded paper to find out what your VC grades
actually are. The filter numbers are often quite different from the
'real' grades.


Wai-Ming Ho wrote:

Hi,

Given the exposure times of a two-filter approach to printing, is there
a way to derive the theoretical effective grade without doing print
matching using all the available grades ?

For example, for a given print on VC paper with condenser/tungsten
projection, I need
12 seconds on grade 0
4 seconds on grade 5

If I was to replace that by a single filter grade, what would it be ?

ps: I use Ilford multigrade filters and Ilford recoomends one extra stop
of exposure for grades above 3 1/2

thanks in advance,
waiming

Nick Zentena wrote:

Wai-Ming Ho wrote:

... I like to know what is used
to measure the wedge density. In case it needs a
densitometer that I don't have.

Basically stick the wedge in the enlarger. Make a print.
Count the number of steps that are neither pure paper white
or pure black. Compare that number to the chart ...


You can close your eyes and plung forward or you
can slow down and take a look at Ilford's own curves
for their own MG papers.
As I've already mentioned and in general, any of the MG
papers show little grade variation below densities of 1-1.5.
The most dense areas do show MG characteristics. Much of
the middle and all of the little dense areas show perhaps
no more than a 2 grade variation twixt 0 and 5 filters.
It's all there in B&W at Ilford's site. In contrast compare
their graded, Galerie in particular, with the MG papers.
I don't work with MG, VC, MC, PC or whatever papers.
If those lousy characteristic curves weren't enough reason
I was to drop them anyway in favor of the much higher level
of darkroom lighting afforded by Graded papers. Dan

wrote:
Nick Zentena wrote:

Need a green and a blue.


Won't yellow and magenta do?
I've checked a few Ilford MG paper characteristic curves.
Over all the lines do not indicate grade untill densities above
1 to 1.5 have been reached. Below those densities grade
lines merge. In effect, for half or more of their density
range those MG papers are little more than a single
grade paper. I was surprised at seeing that.
No wonder split filtration is used so and to the extreme.
Ilford's MG is in contrast with their Graded Galerie paper.
Each Grade's curve is distinct from one another toe to shoulder.
The grade is in the paper, no splits needed. Dan

Graded paper is not perfect, either. I do prefer to use graded paper
for serious work.

Very seldom do you need the great range that today's VC papers provide.
Many photographers must either have horrible negatives or want
grotesquely distorted tonality.

I hardly ever change filtration, usually hovering around grade 3.

Almost every so-called 'creative technique' used in photography is
actually some form of image degradation. I want none of that.

wrote:

Nick Zentena wrote:

Wai-Ming Ho wrote:

... I like to know what is used
to measure the wedge density. In case it needs a
densitometer that I don't have.

Basically stick the wedge in the enlarger. Make a print.
Count the number of steps that are neither pure paper white
or pure black. Compare that number to the chart ...



You can close your eyes and plung forward or you
can slow down and take a look at Ilford's own curves
for their own MG papers.
As I've already mentioned and in general, any of the MG
papers show little grade variation below densities of 1-1.5.

I have a set of negatives (after a development accident) with densities
below that. The filters and MG don't do much except in areas where the
densities (window back light) are of a reasonable level. I couldn't
believe it then, but now it makes sense.

The most dense areas do show MG characteristics. Much of
the middle and all of the little dense areas show perhaps
no more than a 2 grade variation twixt 0 and 5 filters.
It's all there in B&W at Ilford's site. In contrast compare
their graded, Galerie in particular, with the MG papers.
I don't work with MG, VC, MC, PC or whatever papers.
If those lousy characteristic curves weren't enough reason
I was to drop them anyway in favor of the much higher level
of darkroom lighting afforded by Graded papers. Dan


I have started using some of the graded RC papers (0 and 3) that I got
from exchanging my 405 polaroid back. Despite their age, the prints look
pretty good from the few trials I have made. Your comments are giving me
more reason to compare what I have in my MG stock(pile).

Wai-Ming Ho wrote:

wrote:

As I've already mentioned and in general, any of the MG
papers show little grade variation below densities of 1-1.5.

I have a set of negatives (after a development accident) with densities
below that. The filters and MG don't do much except in areas where the
densities (window back light) are of a reasonable level. I couldn't
believe it then, but now it makes sense.

The most dense areas do show MG characteristics. Much of
the middle and all of the little dense areas show perhaps
no more than a 2 grade variation twixt 0 and 5 filters.
It's all there in B&W at Ilford's site. In contrast compare
their graded, Galerie in particular, with the MG papers.

I have started using some of the graded RC papers (0 and 3) that I got
from exchanging my 405 polaroid back. Despite their age, the prints look
pretty good from the few trials I have made. Your comments are giving me
more reason to compare what I have in my MG stock(pile).


I in no way ment to imply that very good quality prints can not
or are not made on MG papers. Ilford's curves were something of
a surprise to me. They claim seven grades. From looking at their
graphs I'd think three a streach. Safely they might be considered
two grade papers below densities of one or a little more.
With their good separation in the more dense areas of the print
they may be the cure for some negatives. Ilford's Galerie though
does show that separation top to bottom.
For myself and Graded papers, MG developers, pre-exposure,
water bath, and other whole print contrast control techniques are
at ones disposal. I suppose those techniques could be used with
MG papers. Graded paper's greatest appeal for me is the much
higher level of darkroom lighting they afford. Dan