Split grade printing - technical analysis?

[MattKing]

It can also be part of non split grade printing though.

OP is asking if in combination of a grade 5 and grade 0 base exposure it produces any thing different than a non split exposure and the only answers have come from Michael and Ralph who've both said no it doesnt

If you burn with a different filter, you are using a relatively small portion of the split grade process.
There is no advantage to using split grade if:
1) you have a light source like a dichroic colour head that already provides for continuous variability of contrast settings; and
2) you never burn and dodge with different contrast settings for different parts of the image.
Otherwise, split grade does provide different results.
Those are fairly limiting conditions, that very few would willingly accept (once they get past early beginner stage).

 

[Pieter12]

A quick question: how many get the paper grade spot-on after a test strip for exposure (not using split-grade printing or any auxiliary equipment such as meters of some sort)?

 

[MattKing]

A quick question: how many get the paper grade spot-on after a test strip for exposure (not using split-grade printing or any auxiliary equipment such as meters of some sort)?

Sometimes I do. I usually make a first guess based on the contact proof sheet and how the negative looks.
Many times I need to adjust.

 

[Pieter12]

Sometimes I do. I usually make a first guess based on the contact proof sheet and how the negative looks.
Many times I need to adjust.

That is one of the reasons I love split-grade printing. You can determine the contrast grade from the 2 test strips (prints in my case--I like to see the entire image) needed for split grade printing. The text strips also give you a good idea of how much to dodge and burn with either filter.

 

[DREW WILEY]

I NEVER get a "grade" unless I'm actually using graded paper. And even when those were predominant, the actual contrast differed somewhat per grade, and could be varied to a significant degree even within grade by the amount of developement. The whole point of VC papers is that you've got the possibility of a full continuum, soft to hard, not a bunch segments like an arthropod. I never give a damn about what "grade" it is. Why does anybody care about that these days? If you do still work with graded papers, the choices of grade are quite limited, and you work with what you can get. This thread being about split printing, the whole concept of grades is obsolete and irrelevant.

At a more exemplary level, I can use all kinds of alternate methods to achieve the same look, any degree of low to high contrast a particular VC paper is capable of.
Common YMC subtractive colorhead, additive RGB colorhead, split printing using hard B and G glass filters over the lens, etc. All basically work. But with any specific negative and paper combination, one method might work more efficiently than another. So I the larger the tool kit available to you, the better.

 

[Pieter12]

I NEVER get a "grade" unless I'm actually using graded paper. And even when those were predominant, the actual contrast differed somewhat per grade, and could be varied to a significant degree even within grade by the amount of developement. The whole point of VC papers is that you've got the possibility of a full continuum, soft to hard, not a bunch segments like an arthropod. I never give a damn about what "grade" it is. Why does anybody care about that these days? If you do still work with graded papers, the choices of grade are quite limited, and you work with what you can get. This thread being about split printing, the whole concept of grades is obsolete and irrelevant.

At a more exemplary level, I can use all kinds of alternate methods to achieve the same look, any degree of low to high contrast a particular VC paper is capable of.
Common YMC subtractive colorhead, additive RGB colorhead, split printing using hard B and G glass filters over the lens, etc. All basically work. But with any specific negative and paper combination, one method might work more efficiently than another. So I the larger the tool kit available to you, the better.

But you do have to determine a grade when using only a single filter. My point is split-grade printing not only offers infinite intermediate grades, but eliminates the task of determining a single grade that one would have to do using a single-filter method.

 

[DREW WILEY]

Here we go again, Michael... For all practical purposes (heard that before?)... I am often using pure blue versus pure green light (if I dial it all the way up). For example, if you take a hard blue 47B filter in combination with a hard 61 green, and view a bright white light source, you get nearly total neutral density, no light getting through at all; black. I actually once used a set of hard color separation filters to view a solar eclipse. Similarly, my additive colorheads can output narrow band primaries equally or even more pure. Yes, "white", rather warmish white, halogen bulbs are behind that, with a continuous spectrum; but that spectrum can be very precisely trimmed to obtain nearly completely pure red, green, and blue, even spectrally tighter than the RGB lasers on big LIghtjet printing devices, for example.

I don't want to get into the technical details, since we'll get into another speed of light debate, and I don't really care in this case because my printing times are deliberately nearly always over 20 seconds, and I have all afternoon to print it anyway.
Incidentally, green laser diodes aren't green to begin with either, but the minor amount of green light filtered out of a red diode - just the opposite of leaves, where green chlorophyll is dominant, and the red seen only when that is naturally removed in the Fall. Or are you still up on Hudson Bay where that doesn't occur? - still trapping disoriented hypothermic muskrats?

Subtractive colorheads differ in the manner yellow, magenta, and cyan are not primaries but secondaries, and their filters always inevitably allow a certain amount of uncorrected white light to pass through. That fact is more important to color printing than VC paper usage, but still applies in principle. But unless one is using faded or worn M and Y filters, it probably isn't worth the fuss to quantify it.

Now for you're ridiculous statement that VC sees "wavelengths, not color". Then why, as everyone knows, are color peaks assigned to specific nm wavelengths? No, paper and film do not see with eyes like we do, but are engineered to produce an equivalent response, color paper in one manner, chromatically, and black and white paper another, relatively neutrally. But either way, it's all based on the characteristic spectral response, which is what color is all about prior to mixture. How the heck did I once work as a color consultant adjudicating things not only with my own eyes, but often assisting that with a color spectrophotometer based on wavelengths? You might want to reconsider your comment. What the heck did you actually mean?

 

[DREW WILEY]

Pieter - No, I don't need to determine any hypothetical grade to print. Why???? That would be just a waste of time. Yes, I know how real graded paper grades perform - I worked with those for years, prior to today's excellent VC papers. But even if the term "grade" didn't even exist, one could still do just as proficient variable contrast printing, perhaps even better because they aren't wasting time redundantly thinking about it.

Paper manufacturers like Ilford tend to use grade potential in relation to specific VC papers as a marketing tool. But the published characteristic curve is better at conveying the potential of the paper. A simple real-deal experimental test strip is better still. People tend to makes things way more complicated than they need to be.

One thing completely neglected so far is that some papers seem to need a certain minimal amount of white or quasi-white light to achieve full DMax. Totally hard split printing might miss the mark in that respect. VC papers are not quite so simple as the just two layer analogy. It takes some time working with each of them in a very specific manner to learn their actual personality in that respect. All the grade talk won't help you much there either. A pair of eyes will.

 

[Pieter12]

Pieter - No, I don't need to determine any hypothetical grade to print. Why???? That would be just a waste of time. Yes, I know how real graded paper grades perform - I worked with those for years, prior to today's excellent VC papers. But even if the term "grade" didn't even exist, one could still do just as proficient variable contrast printing, perhaps even better because they aren't wasting time redundantly thinking about it.

Paper manufacturers like Ilford tend to use grade potential in relation to specific VC papers as a marketing tool. But the published characteristic curve is better at conveying the potential of the paper. A simple real-deal experimental test strip is better still. People tend to makes things way more complicated than they need to be.

One thing completely neglected so far is that some papers seem to need a certain minimal amount of white or quasi-white light to achieve full DMax. Totally hard split printing might miss the mark in that respect. VC papers are not quite so simple as the just two layer analogy. It takes some time working with each of them in a very specific manner to learn their actual personality in that respect. All the grade talk won't help you much there either. A pair of eyes will.

Of course you don't. You are using a split-grade method. It is for those who use a single-filter method that need to determine the grade.

 

[DREW WILEY]

Read all the things I stated. I work with VC papers all kinds of methods, more than I'd care to explain here, not just "split printing". Grade terminology is irrelevant to any of that. That's just an holdover from the past. If people like to think in that manner, and find it helpful, that's their choice of course. But it's completely unnecessary for getting from Point A to Point B with any VC paper. All you need to understand is higher versus lower contrast, and which filters apply.

 

[Pieter12]

higher versus lower contrast, and which filters apply.

Isn't that what grades are about?

 

[DREW WILEY]

The problem with "grades" is that they're segmented and in a somewhat arbitrary manner. There was no universal standard. The advantage of simply directly stating low contrast versus high contrast instead is that a full continuum all the way in between is what is being implied, which is actually the case with VC papers. Not only so, but you can take any given paper to its actual limit without binding it to the extremes to any alleged grade, be it either 0 or 5 - just what it actually is, visually. It's analogous to the film Zone System : No, the world was not created in eight discrete zones of illumination, nor limited to those. It's just a convenience model, sometimes inconvenient. Likewise, in this case.

If somebody enjoys the challenge of quantifying all that, good for them. But it's totally unnecessary for sake of achieving the highest print quality; every bit of that can be done visually; and in my opinion, far more easily that way alone. The paper manufacturers have already done the heavy lifting technically. No need to repeat all that unless you're just curious about it, and then you'd have to get into all kinds of formulation and coating science too.

 

[cliveh]

It isn't an either-or proposition.
I am capable of doing some fairly elaborate digital manipulations using the Corel products I have, but I am much more likely to do that if my desired output is digital display.
I like making darkroom prints, and complex printing schemes can really be fun.
Tell me Clive, do you ever go to someone's home, enjoy a beautifully prepared meal, and then ask the host why they don't order delivery?

No, but that is not a very good analogy. Digital photography is now the norm. Like it or hate it, chemical photography is now consigned to history.

 

[Lachlan Young]

Colour has to do with the brain. If a paper is sensitive to 450nm, it doesn’t care whether that wavelength is passed through a magenta filter or a narrowband blue filter. Of course paper speed will change depending on how much 450nm radiation gets through, but that’s all.

A few questions:

How do you know the transmission properties of say Ilford 5 and 00 filters?

Why would you use a narrowband blue? Why not a bandpass violet or magenta? Seems that would make more sense since the emulsion is sensitive to those wavelengths also.

Why assume a narrow band of blue wavelengths would necessarily give the highest contrast? In order to choose your two filters, you’d really need to know the spectral sensitivities of the individual emulsion components of a VC paper.

The Ilford MG 500 head (the blue/green filter version) uses a narrow bandpass blue filter on one lamp (essentially as close to a #47 as these things go) and both Ilford and Kodak have shown that it cannot deliver beyond about G4.5 while the magenta G5 filter (and some magenta dichroics) can deliver a G5 (or apparently even a bit more in the case of the MG400) - presumably because they pass a bit deeper into the blue.

 

[Nicholas Lindan]

It's not delving into the blue/magenta that increases contrast, it's removing (or never adding) the proportion of green.

 

[Lachlan Young]

It's not delving into the blue/magenta that increases contrast, it's removing (or never adding) the proportion of green.

If you set 'G5' on the MG 500 controller, it is purely exposing through the blue filter, no power goes to the green filter bulb at all.

 

[Nicholas Lindan]

If you set 'G5' on the MG 500 controller, it is purely exposing through the blue filter, no power goes to the green filter bulb at all.

The question is how well does the blue filter block green light.

The paper can be seen as a mix of an old-fashioned blue sensitive emulsion mixed with an orthochromatic emulsion. The technology for blue and ortho emulsions goes back over 100 years. The first VC papers came out in the 1930's. There is really no rocket science here - but there is probably quite a bit of subtlety in getting the two emulsion's HD curves to lie right on top of each other. As long as both emulsions get the same effective exposure (it is usually assumed that both are equally sensitive to blue) the contrast will be at a maximum and the issue of blue/green balance becomes mute.

The spectral sensitivity is probably pretty close to the blue & orthochromatic film curves.

Kodachrome used a variation to make a color film: a blue sensitive layer, an orthochromatic layer and a panchromatic layer with a yellow colloidal silver layer in the middle somewhere. Another 1930's invention. The film was simple, the processing wasn't. I used to know this all better, it's all on the www, somewhere.

 

[Lachlan Young]

The question is how well does the blue filter block green light.

Not really. Compare a #32 and a #47 below 430nm - or for that matter what the CC Magentas are doing (easy enough to roughly extrapolate 50M to 200M). Their ability to block green is (in the context) not that dissimilar, but the differences are in blue transmission below 430nm.

 

[MattKing]

No, but that is not a very good analogy. Digital photography is now the norm. Like it or hate it, chemical photography is now consigned to history.

No, chemical photography is far from being consigned to history.
It is a much smaller niche then it once was, but that niche is still large enough to support an industry infrastructure, educational resources and what seems to be an infinite number of Youtube presenters, social media podcasts and blogs about the subject.

 

[Pieter12]

No, chemical photography is far from being consigned to history.
It is a much smaller niche then it once was, but that niche is still large enough to support an industry infrastructure, educational resources and what seems to be an infinite number of Youtube presenters, social media podcasts and blogs about the subject.

On the other hand community colleges and universities are shutting down their darkrooms more and more, unfortunately leaving Youtube as a primary source of (mediocre) instruction.

 

[MattKing]

On the other hand community colleges and universities are shutting down their darkrooms more and more, unfortunately leaving Youtube as a primary source of (mediocre) instruction.

There are actually a few opening them up anew as well. Geographically, it is very inconsistent.

 

[CMoore]

For me the advantage of split grade is, that it makes printing easier.
Imo “normal” printing is like one equation with two unknowns, time and gradation. You can only solve it with trial and error. With split grade you can forget about gradation, there is only time. Time to reach the maximum black you want and time to get the detail you want in the highlights. you may get the same result with other methods, but it will take a lot more effort and experience.
The Heiland system makes it even a lot easier, but not everybody may want to do the investment.

I have 2 questions.....

1. Is that pretty much always your process.?
You first test with one filter for "Maximum Black'......and then you test with the other filter for highlight detail.?

2. Do you make a "Normal Print" at all before you start the split process.?
Not anything that is finished, but just something you can look at.?
Or do you judge everything just from the negative projected onto the easel or piece of paper.?

I have not been in the darkroom long at all.
I work, 99% of the time, with 35mm.
When i HAVE done split printing, i found it easier to make a print of some size, so i can get an idea of what i have.
Then i proceed similar as you describe above.

 

[DREW WILEY]

Lachlan - I have a lot of experience both the the deepest magenta filter once available from Wratten for specific minus green graphic work, as well as an equivalent violet one (somewhat more blue) which might or might not have more green blocking power than a 47 blue, but certainly not as much as either a 47B or my own blue channel on the additive enlarger. These specific magenta and violet filters are significantly deeper than anything Ilford offers, and would be way too expensive apiece to use in an enlarger filter drawer, perhaps below the lens. No longer made. Probably nobody would remember what they were originally for. I still sometimes use them with reference to certain masking color-correction protocols in relation to color printing, not black and white. They'd be utter overkill for VC split printing.

But debates like this tend to get a little silly, since most VC papers aren't going to resolve distinctions at that extreme very well. Depends on a variety of factors. In my own experience, there is almost no distinction between a 47 and 47B in effect. But it is easier to see what you're doing, dodging and burning, with the less dense 47. But if someone needs to go to that contrast extreme on a routine basis, maybe they should be thinking about why they so badly underdeveloped the negative to begin with. I do it specifically in conjunction with registered unsharp masks, which reduce overall contrast, yet at the same time enhance microtonality the full distance once the contrast is boosted back up in the enlarger and during development.

Incidentally, when I'm not doing VC printing with an actual RGB additive colorhead, it's with a high output 12x12 inch Aristo blue-green cold light (not blue or green, but blue-green, so to significantly either increase or lower the contrast, a supplementary filter is needed, ideally either B or G, whereas Y or M would add some annoying visual neutral density. Otherwise, it's right around mid-range with most VC papers).

 

[Pieter12]

I have 2 questions.....

1. Is that pretty much always your process.?
You first test with one filter for "Maximum Black'......and then you test with the other filter for highlight detail.?

2. Do you make a "Normal Print" at all before you start the split process.?
Not anything that is finished, but just something you can look at.?
Or do you judge everything just from the negative projected onto the easel or piece of paper.?

I have not been in the darkroom long at all.
I work, 99% of the time, with 35mm.
When i HAVE done split printing, i found it easier to make a print of some size, so i can get an idea of what i have.
Then i proceed similar as you describe above.

The method I learned is this:
First you make a test strip just with the 00 filter. Determine the best time that just starts to show highlight detail. Using that time, expose the test strip with the 00 filter, then make incremental exposures to that strip with the 5 filter. Examine that strip and use the time that gives the shadow detail you want. Then make a full print using the time determined by first test strip with the 00 filter, followed by the 5 filter exposure determined by the second test strip. Make any fine-tuning to the times as needed and burn and dodge to taste for the final print.

 

[DREW WILEY]

Pieter - you can indeed try that approach as part of the initial learning curve of split printing, but it probably won't be long till you intuitively recognize how to do it way faster. There is no silver bullet method, simply because there are so many potential combinations or paper and developer, plus dev time options, the effects of toners afterwards, on and on it goes. And as far as I'm concerned, there is no such thing as a "normal print" either. That sounds awfully boring. I interpret every single negative differently, to get the best out of it according to my own esthetic taste, not some moldy old textbook stereotype.