Understanding Split Grade Printing

albada said:

Green(00) and blue(5) not only determine tone, but also contrast, which confuses things for me. That's why I created the table of all four possible dodges and burns. It tells me what those dodges/burns can do for me. For example, below is a straight print (left) and dodged print (right) that I made a few days ago:



I dodged the green exposure for 8 out of 16 seconds below the platform. The table says doing so will boost shadow-contrast, and it did. The table also says light tones will be lightened, and you can see that the foliage below the platform is lighter. I wanted the understructure of the platform to be more visible, and this dodge worked.
I have little experience with split-grade, so I'm wondering what else can be done with split burns/dodges. Hence the table and my question to everyone, which is:

What other good things can split-grade burns/dodges do?

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Independent of the table, I think you've got a good handle on it. Dodging and burning highlights without affecting nearby shadows is useful. Dodging and burning shadows without affecting nearby highlights is useful as well. It's a great technique.

The table is nice, but I want to see the difference in the prints.

Pieter12 said:

What is contrast but the relative tonal values in a print?

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Actually how the tones compare to each other. And in this context, how that comparison is affected by changes in exposure.
The OP's initial table seems more oriented to fixed single tones, not how the range of several tones changes.

MattKing said:

Actually how the tones compare to each other

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I believe that is what is meant by relative.

Pieter12 said:

I believe that is what is meant by relative.

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Yes, but the Op's comment was "Green(00) and blue(5) not only determine tone, but also contrast, which confuses things for me. " Note the singular "tone", not range of tones.

MattKing said:

Yes, but the Op's comment was "Green(00) and blue(5) not only determine tone, but also contrast, which confuses things for me. " Note the singular "tone", not range of tones.

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Actually, I'm not the OP, but because my question was similar, I revived this thread. Here's a crop from the OP's question:


Notice that the two grade-5 exposures seen in the left column have *no* tone; the paper is white. Yet they darkened the grade-00 exposures in the right column. What's going on here?
After much pondering, I finally figured out how to figure out split-grade by using the characteristic curves supplied by the paper vendor. Here's an annotated crop for Ilford's latest RC paper:


This example is for burning green. Adding green exposure shifts the entire image rightward on the X-axis. Above, I've shown the shifts for highlights (H) and shadows (S) on the X-axis. On the left (highlights), the new curve is *above* the old curve, causing a large darkening of highlights. On the right (shadows), the opposite happens. The new curve is *below* the old, causing little change in shadows.
For the example crop from the OP, adding blue shifted the 00-image rightward, darkening it. It's irrelevant that blue-only was below the threshold.
I finally understand not only *what* split-grade dodging/burning do, but also *why*. Unless I'm wrong about all this. I'm open to correction...

albada said:

Notice that the two grade-5 exposures seen in the left column have *no* tone; the paper is white. Yet they darkened the grade-00 exposures in the right column. What's going on here?

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Simple. Grades 4 & 5 filters require 1-1/2 to twice the exposure than the softer grades. From the data sheet:
"‘Guide’ exposure times for filters 00–31/2 are generally the same; but filters 4–5 will need additional exposure times – typically between x1.5 to double the time."

It's so darn much easier to understand all this if you simply set aside all that, "Grade this, Grade that" talk, and simply realize that VC papers potentially give you a continuum, with green or yellow filtration going the lower contrast direction, and blue or magenta toward toward higher contrast. Grade jargon made sense with real graded paper. But with split printing you don't need to worry about any of that to get optimal results. And the deeper the blue versus green the filter set is, the stronger the effect.
Of course, you can always use milder filters for an intermediate effect. A simple test strip can visually tell you everything you need to know, to at least get you on first base. That's important because different brands of paper often behave a little differently to split printing strategy. For certain ones, you can't even get a full DMax if at least a token amount of green light is added to the dominant blue exposure - perhaps evidence of a more complex paper emulsion than just two basic layers.

Otherwise, due to experience, I can achieve virtually identical results on VC paper using my conventional CMY colorheads, my RGB true additive colorheads, or my V54 blue-green cold light with optional hard blue vs hard green glass filters over the lens (namely, 47 blue versus 58 green). But ordinarily, my first test strip is done with plain light, and I go from there. It gets fast and intuitive after awhile. Often a single test strip is all I need.

But don't expect dense blue and green filters to obey the kind of time adjustment rules expressed in the previous thread. It all depends on the specific light source to begin with; and pure blue is a lot denser and slower to print than green. It's not like working with amber versus magenta VC sheet filter sets.

"Tone" is a tricky term. In color theory it means something completely different than seemingly here or in AA's Zone System jargon. He also synonymously mystified the term, "value" (no doubt as shorthand for grayscale value, which he should have spelled out in full). With reference to black and white printing, I personally use the expression "tone" only when referring to some actual perceptible indicative color shift due to a toning bath - a toner - whether selenium, gold toning, sulfide, split toning, etc.

In color theory, tone is opposite of tint. "Tone" means the addition of white, lightening hues; "tint" means darker or more black. More saturation of color is expressed by "chroma". But now we've got all kinds of computer-speak too, further confusing the terminology. Throw in some cellphone texting acronyms, and even the CIA probably couldn't decipher the meaning.

Each negative could be different or a group could all behave the same way.

1. First I do a straight print. I may time exposure strips across the paper first.
2. Then I do a print a a selected grade. I may time exposure strips across the paper first.
3. Then I start the split grade with the strongest magenta file with time exposure strips across the paper. Once best print is found, I make a print that way and then use strongest yellow file with time exposure strips across the paper. From that print I now have the exposure for the magenta and yellow filter and make the print. At that point I can start burning and dodging with the magenta filter. Then I can work out the burning and dodging with the yellow filter.

Sirius Glass said:

Each negative could be different or a group could all behave the same way.

1. First I do a straight print. I may time exposure strips across the paper first.
2. Then I do a print a a selected grade. I may time exposure strips across the paper first.
3. Then I start the split grade with the strongest magenta file with time exposure strips across the paper. Once best print is found, I make a print that way and then use strongest yellow file with time exposure strips across the paper. From that print I now have the exposure for the magenta and yellow filter and make the print. At that point I can start burning and dodging with the magenta filter. Then I can work out the burning and dodging with the yellow filter.

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Sounds like the hard way, using a lot of paper. I was taught to make a test print with the 00 filter, look for the shortest exposure showing highlight detail. Then using that time, make a print with the 00 filter followed by test strips with the 5. Use the time from the strip showing the shadow detail and blacks you want. You usually can judge what needs to be dodged and burned and with which filter from those two test prints. Now you can make a final print using the 00 and 5 times and dodging and burning as needed. A fourth print may be necessary to fine-tune everything.

I have seen people make a checkerboard test print with both the 00 and 5 filters, but I find it difficult to judge the exposure times using that method the one time I tried. But it does eliminate one test sheet.

Sirius Glass said:

Each negative could be different or a group could all behave the same way.

1. First I do a straight print. I may time exposure strips across the paper first.
2. Then I do a print a a selected grade. I may time exposure strips across the paper first.
3. Then I start the split grade with the strongest magenta file with time exposure strips across the paper. Once best print is found, I make a print that way and then use strongest yellow file with time exposure strips across the paper. From that print I now have the exposure for the magenta and yellow filter and make the print. At that point I can start burning and dodging with the magenta filter. Then I can work out the burning and dodging with the yellow filter.

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Pieter12 said:

Sounds like the hard way, using a lot of paper. I was taught to make a test print with the 00 filter, look for the shortest exposure showing highlight detail. Then using that time, make a print with the 00 filter followed by test strips with the 5. Use the time from the strip showing the shadow detail and blacks you want. You usually can judge what needs to be dodged and burned and with which filter from those two test prints. Now you can make a final print using the 00 and 5 times and dodging and burning as needed. A fourth print may be necessary to fine-tune everything.

I have seen people make a checkerboard test print with both the 00 and 5 filters, but I find it difficult to judge the exposure times using that method the one time I tried. But it does eliminate one test sheet.

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Then eliminate the first two steps. A grid sounds hard to keep track of each area.

DREW WILEY said:

"Tone" is a tricky term. In color theory it means something completely different than seemingly here or in AA's Zone System jargon. He also synonymously mystified the term, "value" (no doubt as shorthand for grayscale value, which he should have spelled out in full). With reference to black and white printing, I personally use the expression "tone" only when referring to some actual perceptible indicative color shift due to a toning bath - a toner - whether selenium, gold toning, sulfide, split toning, etc.

In color theory, tone is opposite of tint. "Tone" means the addition of white, lightening hues; "tint" means darker or more black. More saturation of color is expressed by "chroma". But now we've got all kinds of computer-speak too, further confusing the terminology. Throw in some cellphone texting acronyms, and even the CIA probably couldn't decipher the meaning.

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Thanks for mentioning that. Munsell used the words "hue", "chroma", and "value". I just looked up "tone" in the dictionary, and it mostly pertains to music and muscle. It can relate to color, but it's defined as a color, not a shade of gray. Munsell's value scale went from 0 to 10, similar to AA's zone scale, but AA defined the points on his scale differently, probably to make the points one stop apart in the scene. AA's description says that "zone" applies to the scene and "value" to the print, but then I catch him using "zone" for prints also. In fact, zones are defined in terms of shades of gray on the print (not in the scene). For me, I treat zones merely as standardized print-densities which are documented in Way Beyond Monochrome (which I recommend). Perhaps AA should have used only the word "value", or "grayscale value" as Drew suggests.

It appears that "split-grade" refers to two activities:

1. Determining print exposure (including "grade"). For most people, this consists of filter-number and time. I'm using a LED-head, so for me, it consists of green-brightness, blue-brightness, and time (GBT). My controller has the paper-curves in its memory, and using those curves, it can figure out GBT from only one test strip. I make a test strip using my best guess of grade, and then I tell the controller, "I want zone w on step # to be zone x on the print, and zone y on another step # to be zone z on the print," and it figures out the GBT. You could do the same thing manually with a calculator and tables representing the curves. One test strip.
2. Determining dodge/burn times of green and/or blue. This one is trickier. My controller can create a test-strip that changes only green or blue, and then I decide based on that. The blue-dodge of the water tank I posted earlier in this thread was decided that way. Do most people decide the time for a split dodge/burn using a test-strip in which only one color is changing? I see no other way around it, except trial and (often) error.

I've learned about the 00-5 method of determining exposure (use 00 to determine highlight time; use both 00 & 5 to determine shadow time; use both times for final print). But as the second column in the OP's matrix shows, filter-5 (blue) darkens highlights, so I think this method would create prints with too-dark highlights and would thus need further correction.

Mark Overton

These are the tables I made for split grade printing. Radial lines are same-contrast (ISO-R from 45 to 190) and tangental lines are same-density. Push pins keep track of the sequence leading to the perfect print, allowing back-tracking, if needed.

ic-racer said:

These are the tables I made for split grade printing. Radial lines are same-contrast (ISO-R from 45 to 190) and tangental lines are same-density. Push pins keep track of the sequence leading to the perfect print, allowing back-tracking, if needed.
View attachment 313747View attachment 313748

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This graph is clever. I spent 30 minutes studying it, and mentally picturing how it would be used to change grade without changing density. Nice.
A few questions:


Again, this graph is helpful. You might want to post instructions on how to use it, because I suspect that many people will be overwhelmed by the many lines and immediately give up.

I’m exclusively split grade printing since I came back to the darkroom some years ago. The reason is that it makes printing a lot easier and faster for us ordinary mortals. I can forget about the whole “grade” thing.
Beside that it takes less paper and chemicals.
I tried to understand, but I don’t have a clue why all this talking about graphs and test prints with different grades.
Imho it makes something that’s there to make things easier, a lot more complicated.

Frank53 said:

I’m exclusively split grade printing since I came back to the darkroom some years ago. The reason is that it makes printing a lot easier and faster for us ordinary mortals. I can forget about the whole “grade” thing.
Beside that it takes less paper and chemicals.
I tried to understand, but I don’t have a clue why all this talking about graphs and test prints with different grades.
Imho it makes something that’s there to make things easier, a lot more complicated.

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+1. I print by eye, not charts.

Pieter12 said:

+1. I print by eye, not charts.

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Ditto.

Pieter12 said:

+1. I print by eye, not charts.

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I don't disagree.
But the grade system does provide a tool that greatly assists us in communicating about our procedures. If I'm at one of my Darkroom Group meetings - in person once again thankfully - people know what I mean when I say that the second of two similar prints was printed with an extra grade of contrast.

MattKing said:

I don't disagree.
But the grade system does provide a tool that greatly assists us in communicating about our procedures. If I'm at one of my Darkroom Group meetings - in person once again thankfully - people know what I mean when I say that the second of two similar prints was printed with an extra grade of contrast.

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And that contrast boost can make some photographs have a bit of pop and stand out more.

Frank53 said:

I’m exclusively split grade printing since I came back to the darkroom some years ago. The reason is that it makes printing a lot easier and faster for us ordinary mortals. I can forget about the whole “grade” thing.
Beside that it takes less paper and chemicals.

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Could you explain how it saves paper and chemicals, please?

snusmumriken said:

Could you explain how it saves paper and chemicals, please?

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With split grade printing I arrive at the final print with fewer number of steps and much less time. Hence saving paper and chemicals.

Sirius Glass said:

With split grade printing I arrive at the final print with fewer number of steps and much less time. Hence saving paper and chemicals.

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Thanks, forgive me for being slow to comprehend, but I still don't get it. Surely you have two variables (rather than one) to nail down through test exposures?

I've used split grade printing to solve problems, but have never really been comfortable with it as a general approach. A bit of motivation (saving money) might be what I need.

snusmumriken said:

Could you explain how it saves paper and chemicals, please?

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What sirius glass said.
With two simple test strips you can find the two right exposures and you don’t have to go looking for the correct grade. Changing the grade often also means changing the times etc.Of course there will be people who find the time and grade they like with just one test strip.but most of us will need more test strips. And less test strips means less chemicals. It’s not much but ok.

snusmumriken said:

Thanks, forgive me for being slow to comprehend, but I still don't get it. Surely you have two variables (rather than one) to nail down through test exposures?

I've used split grade printing to solve problems, but have never really been comfortable with it as a general approach. A bit of motivation (saving money) might be what I need.

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As posted several pages ago:
I start the split grade with the strongest magenta file with time exposure strips across the paper. Once best print is found, I make a print that way and then use strongest yellow file with time exposure strips across the paper. From that print I now have the exposure for the magenta and yellow filter and make the print. At that point I can start burning and dodging with the magenta filter. Then I can work out the burning and dodging with the yellow filter.

Sirius Glass said:

I start the split grade with the strongest magenta file with time exposure strips across the paper. Once best print is found [...]

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"Best print" at lowest contrast (max magenta) will have too-dark highlights and too-light shadows. Or did I misunderstand?