Differences in grades of VC paper

Bill Burke wrote this on another thread, which I did not want to turn into a technical discussion and be responsible for fulfilling the inevitable end of that thread.
"OK just printing.

Here's how to select the proper contrast grade for printing.

Stock two grades of paper: Grade 2 and Grade 3.

If you have a thin, weak negative: Print on Grade 3.

If you have a rich, strong negative: Print on Grade 2.

If that doesn't work find another negative.

This may sound tongue-in-cheek, but is actually what I do. I found myself flustered with Multigrade paper. Too many choices. Never did figure out what to do next if a test print without a filter didn't look right. Now the only time I reach for Multigrade... is when I need Grade 4. "

So this prompted me to ask what is the differences to be expected if printing the same scene and same exposure negatives which differ only in the length of developing time.
Getting into Platinum Palladium printing has necessitated more contrast in some of my negatives. This has led me to increase developing times incrementally, to get where I need to be.
While printing those, I thought about the relationship between VC paper and negative contrast.
I am aware of the shelf in some papers at softer grades and middle tones. I am asking about other than that.
Here the Question
Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see? The negatives being identical in subject and exposure and everything else.
Thanks
Bill

In another thread a new APUG member wrote that he had printing times of 2 minutes, and that got me to thinking about how much printing time changes with development.

To get a feel for it...

I look at sensitometry graphs of development times and curves, and simply count out by 0.3's - a negative with 0.3 more density than another requires one stop "more printing time" and on one of my graphs, the midtones jumped about 0.3 in density with development time change from 13 to 16 minutes.

On the side of exposure: supposing a 0.5 gradient which is a good normal... Two f/stops difference in exposure (0.6 in exposure change) leads to 0.3 in density change (again one f/stop of aperture or time change when it comes to printing).

If you don't have a densitometer, you can get a feel for negative densities by noticing how long it takes to print.

How about what Ansel Adams and others wrote: Start with grade 2 and get the exposure for the high lights. If the blacks are to blocked go to grades 00, 0, or 1. If the blacks are too weak move progressively to 3, 4, and 5 as necessary.

noit very good

In my humbug opinion, variable grade papers are not very good. They are okay from a grade two through about a 3.5 but then fall on their faces. "Back in the day" I used to use single grade papers one through six. I don't know if you can get single grade six any more. Variable grade paper will not give you a true grade 4, or higher, IMO.

cowanw said:

B
Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see? The negatives being identical in subject and exposure and everything else.
Thanks
Bill

Click to expand...

The tone reproduction curve for all those cases is always messed up due the characteristics of the film and paper. There is no one best answer, though, Steve Benskin posted a reproduction curve that showed a negative developed to print on #3 and a negative developed to print on #2 paper were pretty similar. I don't have tone reproduction curves for the extreme cases, but likely they will be more distorted than these two.

(there was a url link here which no longer exists)

Originally posted by Stephen Benskin: I've attached a tone reproduction curve example. This curve represents how the print value's relate to the original scene's. One curve represents a 1.80 LSLR scene processed Normal and printed on a higher grade of paper (grade 3). The other curve represents a 1.80 LSLR scene processed N+1 and printed on a normal grade of paper (grade 2). In the top right hand corner of the curve are the gradients for each step. The N+1 curve has higher gradients in the mid-tonal range and the Grade 3 curve has higher gradients in higher tones.

Both curves have higher mid-tone gradients than with a "normal" curve from a 2.1 LSLR processed normal and printed on a grade two. The straight line is a reference curve that represents the original scene. Any tones falling over the reference curve are darker than the original tones and any tones falling below the reference curve are lighter than the original scene. A preferred tone reproduction curve that "looks" like the original scene generally fall about 0.15 logs below the reference guide (except for the highlight). I've added a tone reproduction curve with a normal reproduction curve as a reference.

Click to expand...

Thank you all.
Yes I have a densitometer and have noticed the connection between density and printing time and have been mentally counting my .3's.
Yes I understand how to get the whites and black's right.
Thank you for your opinion re VC paper.
I should just refine the Question.

Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see viewing the prints?

ic-racer said:

The tone reproduction curve for all those cases is always messed up due the characteristics of the film and paper. There is no one best answer, though, Steve Benskin posted a reproduction curve that showed a negative developed to print on #3 and a negative developed to print on #2 paper were pretty similar. I don't have tone reproduction curves for the extreme cases, but likely they will be more distorted than these two.

(there was a url link here which no longer exists)

Click to expand...

Yes, this is what I am wondering. I am not thinking in this example there is much difference. I hope someone can speak to the more extreme cases
Thanks
Bill

cowanw said:

Thank you all.
Yes I have a densitometer and have noticed the connection between density and printing time and have been mentally counting my .3's.
Yes I understand how to get the whites and black's right.
Thank you for your opinion re VC paper.
I should just refine the Question.

Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see viewing the prints?

Click to expand...

I'll take a stab and say the answer should be no difference in appearance.

I kind of agree with Bill in that one can make excellent prints from all those conditions, however, in an experiment the prints will have subtle differences when viewed side-by-side. For example the print on #5 paper will have augmented grain structure whereas the print on #0 may have mushy grain structure. This may cause perceptible differences in what appears "sharp." Also, any unevenness of the enlarger light will be accentuated by the #5 print and minimized in the #0 print. Dodging and burning will be a royal pain in both extreme cases. In the #5 print frustration arises because one can't time the dodge or burn accurately enough to be consistent from print to print (due to the narrow latitude of the high contrast emulsion). In the #0 print, frustration arises because doubling or tripling a burn time might not even be noticed in the print due to the extreme latitude of the low contrast emulsion.

So, when using multigrade paper, even though one can make good prints from negatives developed to a wide range of contrast levels, it is probably prudent to still be very careful with negative development and aim to print on grades from 1.5 through 3. Not necessarily for aesthetic reasons, but for technical reasons.

ic-racer said:

I kind of agree with Bill in that one can make excellent prints from all those conditions, however, in an experiment the prints will have subtle differences when viewed side-by-side. For example the print on #5 paper will have augmented grain structure whereas the print on #0 may have mushy grain structure. This may cause perceptible differences in what appears "sharp." Also, any unevenness of the enlarger light will be accentuated by the #5 print and minimized in the #0 print. Dodging and burning will be a royal pain in both extreme cases. In the #5 print frustration arises because one can't time the dodge or burn accurately enough to be consistent from print to print (due to the narrow latitude of the high contrast emulsion). In the #0 print, frustration arises because doubling or tripling a burn time might not even be noticed in the print due to the extreme latitude of the low contrast emulsion.

So, when using multigrade paper, even though one can make good prints from negatives developed to a wide range of contrast levels, it is probably prudent to still be very careful with negative development and aim to print on grades from 1.5 through 3. Not necessarily for aesthetic reasons, but for technical reasons.

Click to expand...

That's been my experience as well. I don't mind using my eyes to decide what I like, but it helps to know what one should be looking for.
Thanks
Bill

snapguy said:

In my humbug opinion, variable grade papers are not very good. They are okay from a grade two through about a 3.5 but then fall on their faces. "Back in the day" I used to use single grade papers one through six. I don't know if you can get single grade six any more. Variable grade paper will not give you a true grade 4, or higher, IMO.

Click to expand...

This is not my experience.I get a true grade 1-5 from Ilford MGIVin FBand RCand regulary use several grades per print;that's the beauty of MG papers.This flexibility gprovides many creative alternatives even with otherwise'perfect' negatives;just sayin'

I was around when the transition from fixed grade to variable grade really started to happen. So I've printed a fair bit on both.

There is no comparison between the variable grade papers now, and then. The original variable grade results were serviceable. The current variable grade papers are capable of far better results than that.

Maybe not a grade 6, but then I never got great results out of grade 6 paper anyways.

Anybody have any more comments on the original question?

Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see viewing the prints?

Given the OP and your comment here in post #14, you should have identical results in the mid tones with some loss of detail in the shadows or highlights depending on film exposure. The problem is, that many designers of VC papers don't vary the toe and shoulder of the paper, or they have a kink in the mid scale and this degrades the final result. There have been articles about this published in magazines.

And, BTW, I have had excellent results with VC papers from grade 1.0 - 4, but above this things are iffy. The best on the market is Ilford IMHO. I also enjoy split grade printing.

PE

thanks for that. My understanding of the new Ilford Classic is that the kink is gone. 'Preciate your chiming in.

cowanw said:

Here the Question
Given a softer negative that prints with grade 4 filter, or a more contrasty negative that prints with a grade 1 filter, or a medium negative that prints with a 2.5 filter; what differences can I expect to see? The negatives being identical in subject and exposure and everything else.
Thanks
Bill

Click to expand...

They should be identical.

Clive, they will not be exactly identical due to the slight loss in detail in toe and/or shoulder as contrast increases. See my post above. If the "data" is not there, it just is not there!

PE

Bill Burk said:

I'll take a stab and say the answer should be no difference in appearance.

Click to expand...

better mid-tone separationand more apparrent sharpness with higher grades

Thanks
Clive, P.E. and Ralph.
Sounds like you give a little and take a little.

Some discussion here about limitations and odd behaviour of VC papers. I don't do much in the way of measurement, but I took advice years ago to make negatives that are not very contrasty so I could use VC level of around 3 or more.

http://www.darkroomautomation.com/support/appnotevcworkings.pdf

cowanw,

How much more contrast are you developing your negatives to... when you make negatives for Platinum/Palladium?

Do you aim for a certain Contrast Index?

I think it would be a shorter road to your answer... to focus the question on the issues that might come from increasing negative contrast:

If it were me, I'd ask:

Assuming 0.62 Contrast Index is my current normal aim, what would be the best compromise aim if I wanted to make a negative suitable for either Platinum/Palladium and Silver Gelatin?

I was afraid someone would ask me a question life this. My problem is I have been unable to determine from various posters word descriptions were to start and finish measurements from and to. Someday I hope to meet with a knowledgeable "densinominator" and have them tell me from my negative. Or get a negative with the measurement spots circled.
So for internal consistency I go from the clearest part of the negative (not the border) to the darkest spot.
My first measurement is consistently about .20 which I presume is base + fog. So I presume my exposure is consistent.

More consistently controlled lighting in the studio and differing development
.20 to 1.51; Delta 1.31, prints on 00
.19 to 1.40; Delta 1.21, prints on 0
.20 to 1.31; Delta 1.11, prints on I
.20 to 1.15: Delta .95, prints on 2
A photograph of my mother indoors precipitated this question.
.20 to .56 which printed best on grade 5.
The grades are Kodak settings on my LPL colour dichroic enlarger.

The platinum issue is a side issue. For Platinum I aim at delta 1.3 or higher and hoped, foolishly, that I could print those on silver at 00.
My next exercise is to copy negatives for silver printing to a higher contrast for Platinum.

Cowanw, film is intended to have a slope of 0.60 - 0.65 using good professional equipment and to be printed on standard silver halide paper. The Delta is not that important, the slope is. After all, the delta in a good lith film is 3 but the slope is infinite when everything is done good and proper for a lith film.

Film in the range of 0.6 - 0.65 will print on a grade 2 paper under normal circumstances or a grade 3 paper if your optical system has an above normal flare when making enlargements. A grade 2 paper has a mid scale slope of about 2.5 if it adheres to normal standards. If you take a speed point on the paper of 1.0 or 0.8, there are also standards for toe and shoulder which can mess with your results if the manufacturer is lax in this area. The speed is determined with a 12" exposure for most enlarging papers in order to eliminate reciprocity problems.

Of course, for most alternative processes or stained negatives, paper contrast must be adjusted due to the spectral sensitivity of the paper and the "color" of the image.

PE

cowanw said:

I was afraid someone would ask me a question life this.

Click to expand...

Sure it will come easily... the densities you are measuring are the "y-axis" and what you don't know for sure is the "x-axis" - exposure.

The missing part is that you need to come up with a good measure of exposure. I am confident enough in the toe... that it doesn't bother me to ignore it. You could pick any place in the middle of the straight line. Make two or three exposures of something gray, 2 f/stops apart and then you will have something you can measure to judge the "slope." You could choose metered exposure, two f/stops under and two f/stops over. That will most likely give you three points on the straight line.

Use a Souffer step wedge!