Split grade printing question

[Ben Calwell]

I've been reading online and watching You Tube videos about split-grade printing. I've always strived to scale my negatives to print on Grade 2 paper, but since graded papers have gone the way of the dinosaurs, I'm forced to use VC papers.
My question is: when is split-grade printing called for? What kind of negative needs to be printed with a combination of low grade and high grade filter? I get the impression that some printers use split-grade printing for every negative.
If a negative prints fine at Grade 2, what's the point in printing it with a combo of low- and a high-contrast filter?

[cowanw]

For me, my 8x10 Zone VI enlarger is broken and I cannot do mixed settings. My 5x7 Ilford 500 system is set in half grades only and my 6x6 LPL is a dial in yellow/magenta system.
You are quite right that overall exposure is the same with a mixed versus a split printing. Being more or less incremental may or may not be significant. A certain number of blue photons plus a certain number of green photons must always give the same effect no matter how they are delivered.
But where split printing shines is burning (or dodging) with just blue light or just green light (whether a additive or subtractive system).
Or it may just be that not everybody thinks, learns, comprehends the concepts the same way.
If all your negatives print fine at Grade 2, then there is no point for you in printing it with a combo of low- and a high-contrast filter. You are good to go!

[Alan9940]

IMO, if a negative can be printed normally on a grade 2 paper or using a grade 2 filter on VC paper, then split-grade printing is of no use; or, more specifically, is not required. Where I find split-grade printing to be a valuable tool is when attempting to print a difficult negative. For me, that's a negative where I cannot get the high and low values to look right at the same time. In that instance, I'll print the high values to my liking through a low contrast filter, then hit the shadow end with a high contrast filter. I don't always use grade 0 and grade 5, as commonly advised about the 'net. Each negative can have different contrast grade needs for each end. YMMV, of course. This is simply how I work.

That said, if you look up Steve Sherman, he specifically designs his negatives to print with more blue light vs green light. According to him, this provides more local contrast that cannot be achieved through any normally developed and printed negative. His prints are certainly lovely.

[Ben Calwell]

Thanks - my old cold light head delivers high contrast on VC paper. I’m thinking I could use that to my advantage on certain negatives, in conjunction with yellow filtration.

[cowanw]

Yellow is minus blue and so yes, if your bare bulb light is high contrast then yellow will take blue away. This assumes that your bare bulb has the required green in it and recognizes that, if you are manipulating the light only by taking light away, your exposure times may need to be longer. And if you lack green, you will actually not change the contrast at all with a yellow filter, merely decrease exposure.

[bob carnie]

I split print every negative... to me its a matter of what does the print need to look like, and with that in mind what kind of negative do I have in my hand at the time... I evaluate the scene I want to produce, then evaluate the negative and with two filter I make the print look like what I envision.

I never change the apeture or time once I have a good first test print close to where I want it with a single filter.... All I do is establish this first balance, which is normally a light and soft print of where I want to go. I then add what I call blasts of grade 5 to increase the contrast to where I want to be, I just hit the timer, sometimes I have a 10 second (filter 1) starting point at two stops down from balance(yes I will adjust the bulbs in the enlarger head to get to this point) and then I have seen myself hitting the grade 5 up to 6 times, while dodging mid areas while I do this.
I also will start backwards and use a Grade 4 filter to determine the basic exposure contrast of the print and will flash in by hitting with a 1 filter and will dodge while I am doing this.

For most scenes I will burn in highlights with a grade 5 filter , which seems silly but , I am trying to make any lower tones within the highlight areas darken to create local contrast... This is the exact opposite but same effect as putting a highlight reducing mask on a contrast mask when I printed positives on Cibachrome, it separates the highlight region

When printing we are always trying to fool the eye, I always dodge as I feel its the weapon of mass destruction.. I started split printing in the late 90's when after beta testing Ilford Warmtone I felt it was a viable way of making the type of prints I want.

[Doremus Scudder]

Split-printing really shines when there are areas you would like to print with different contrast. If you're split-printing, but not dodging or burning with different filtration from the base exposure, then you can achieve exactly the same result with a single intermediate contrast setting.

Many split-grade printers, like Bob above, end up printing most highlights at a different contrast than mids and lows just by their method. I'll often dial in full contrast and burn highlights as well. The possibilities are endless.

That said, there were a whole lot of really great prints made on graded paper at one contrast setting. One can do that with VC paper as well. I usually make my best print at one contrast setting and then determine if split printing will benefit the print. I resort to split-printing in a pretty small percentage of my work with the exception of some judicious highlight burning at the high contrast setting, which I end up doing fairly often.

Hope this helps,

Doremus

[John Layton]

When I began split grade printing about seven years ago...I tended to think in terms of "equivalents" to numbered contrast filters, and initially valued the fine tuning that split grade offered to delve between these values. This tendency fizzled out...to where I no longer thought in terms of numerical contrast values at all. Indeed, to the extent that I typically now utilize a variety of spectra in creating a single print, the process has gotten to feel much less "linear." What I have found over time, is that my approach to creating prints has changed to something which feels much more fluid and intuitive, while at the same time I think I work harder, and find myself more constantly engaged...because the toolbox is now much more comprehensive and thus more demanding. The reward for this is that I now find myself more consistently satisfied with my prints, and more confident...when I get a negative which I might have hesitated to print in the past - that I can go ahead and make it work for me.

[Greg]

To be honest it has been quite a few years since I split printed anything, but from around 1980 till 2000 I pretty much split printed most of my negatives. I read how several photographers did their split printing, and tried probably 4 of their procedures. In the end settled on one procedure and modified it to fit my method of printing. I ended up actually using a color head. Never had any problems with movement between adjusting the filters cause my enlarger columns were very solidly "bolted" the the wall behind them. Used a Leitz Focomat V 35 Color and a Durst Laborator CE 1000 with a CLS450 color head. Recently have gone back to printing with that same Durst Laborator CE 1000 with a CLS450 color head. Now trying to find my notes on how I did it back then. Unfortunately have only found my lab notebooks going back to 1991. So now have records of all the B&W film that I had processed since then, but in 1991 I was split printing by habit and kept no notes on how I did it... However you decide to split print, keep detailed notes.

[Drew Wiley]

Split printing is just one more optional tool in my substantial tool box. Use it when I need to.

[ic-racer]

The full filter set is not that expensive, so when using VC paper, I'd just get all filters and do a single exposure.

[Drew Wiley]

Split printing using deep green versus deep blue filters allows a greater contrast range. But I can make virtually identical prints using my blue-green V54 cold light, split printing using hard 47 vs 61 glass filters over the lens, using dedicated channels on my additive RGB colorheads, or using M versus Y on my subtractive heads. No need for a filter set when a continuous filter range is right in the head itself. Normally I just use the raw light unmodified. But then going back and punching in a tweak of hard blue or green can solve issues difficult for any intermediate filter alone. Sometimes I deliberately make 8x10 negs so thin that the silver image isn't even visible; but a deep blue filter translates the pyro stain itself into a wonderful full-scale print. At other times, the original neg range is reduced via an unsharp mask, and then all that sandwiched tonality expanded on VC paper using a deep blue filter, resulting in highlight detail and midtone microtonality otherwise unachievable.

[Chester McCheeserton]

But where split printing shines is burning...
If all your negatives print fine at Grade 2, then there is no point for you in printing it with a combo of low- and a high-contrast filter. You are good to go!

+1

I find burning with the 00 filter (or the yellow dial all the way maxed) incredibly useful for enlarging. In fact I got so used to having the ability to selectively darken with that lower contrast that the few times I've tried to return to graded paper I'm usually not happy with the prints...I never did get the big advantage of split filter printing other than burning, none of the serious printers who taught me used it with any regularity....only trying it on the occasional difficult negative....

[esearing]

If you are using filters you may find you like certain images using grades 1 and 4 instead of 0 and 5 . And you can do things like start with a 2.5 and do additional burning with higher or lower grades as needed. If you have a head that only uses green/blue lights then you have to get a bit creative with your timer. I am still trying to figure out what to do when a negative has a high contrast vs one that has low contrast (highkey, low key, Middle of the zones) - My first thoughts are usually wrong and I usually end up at a higher grade than when I start. It really takes several images to get a feel for it unless you like printing step wedges.

[Joe O'Hara]

I often burn in edges and corners, when they are too light, with a grade or so lower than the basic exposure. Done properly, it doesn't over-darken the lower tones but it lowers the high tones to where they need to be.

On negatives that I've printed on lower contrast grades, sometimes the print seems to lack any solid blacks. A brief all over exposure to grade 4-1/2 light often sets the blacks in nicely and makes the whole print much better, affecting the mid-and high values little if at all. Only a short exposure is needed-- if the basic exposure was say 35 seconds at f/11, try 6 seconds at f/16 for the high-contrast exposure.

This also works to emphasize the contrast in e.g. a cloudy sky that shows tone with the basic exposure, but no texture.

I split-contrast print along these lines probably 75% of the time.

[Steve Sherman]

I Split-Contrast print with only grades 0 and 5. IMHO, anytime the use of middle grades is used the mid-tones become increasingly contaminated with Green light. Since Mid-Tone contrast is the single most difficult aspect of the Silver print to affect, the less Green or 0 filtration used offers more printing flexibility. This article I wrote maybe of help to those unfamiliar with a deep dive into Multi-Contrast papers. https://unblinkingeye.com/Articles/Flashing/flashing.html

[John Layton]

I also typically just use "full green" and "full blue" (00.0 and 5.0 on the Heiland unit). Then again, there are times when I've split between adjacent values...in this case (see photo - not a great copy, sorry) an equal split between 1.6 and 1.7. Anything else or anything further apart simply did not work. 202782

[Steve Sherman]

resulting in highlight detail and midtone microtonality otherwise unachievable. Unless of course, you were to process the film via the Extreme Minimal Agitation technique

[Drew Wiley]

Well, there is always masking for those extra special negs. That's one way to have your cake and eat it too. Full tonal expansion with development, then an appropriate mask, then printing high-contrast on VC paper using blue filtration. But it can be overdone if one is not careful.

[Joe O'Hara]

I also typically just use "full green" and "full blue" (00.0 and 5.0 on the Heiland unit). Then again, there are times when I've split between adjacent values...in this case (see photo - not a great copy, sorry) an equal split between 1.6 and 1.7. Anything else or anything further apart simply did not work. 202782

Whatever your technique, the picture here is lovely.

It's all about the print.

[Ben Calwell]

I Split-Contrast print with only grades 0 and 5. IMHO, anytime the use of middle grades is used the mid-tones become increasingly contaminated with Green light. Since Mid-Tone contrast is the single most difficult aspect of the Silver print to affect, the less Green or 0 filtration used offers more printing flexibility. This article I wrote maybe of help to those unfamiliar with a deep dive into Multi-Contrast papers. https://unblinkingeye.com/Articles/Flashing/flashing.html

Steve,
Thanks for the link to your article. I don’t understand the use of green and blue filtration. What kind of enlarger light are you using? I’ve always used yellow filters for low contrast and magenta for high contrast with white light. I have an old Aristo cold light head, and everything I read says I need a 40cc yellow filter to get normal contrast with that head.
I’m trying to come to grips with using VC paper with this head after years of using graded papers. Should I be using green and blue filters instead of yellow and magenta?

[Pere Casals]

What kind of negative needs to be printed with a combination of low grade and high grade filter?

If you are not to burn/dodge then Split grade is the same than using garded paper of a certain grade or using a particular contrast filter grade in VC paper. Insted using a cantrast filter allowing to pass more blue or more green lights you throw the amount od green or blue light by adjusting exposure of green and blue. Red is irrelevant because paper is insentitive to it... so it's the same if you throw green than is you throw yellow, as yellow is green plus irrelevant red.


The difference comes when you dodge/burn during the green or the blue exposure. You may also make the general exposure with (say) grade 2.5 and later burning highlights with grade 0 and shadows with grade 5.


You require split grade when wanting to dodge during blue or green exposure... for the rest it's mostly the same but taking a different path.

When adjusting exposure/grade with regular printing with contrast filters you usually (may) first adjust exposure for the highlights and later you adjust grade to darken shadows to the point you want. With split grade you start adjusting time of green light to adjust your hioglights and later you adjust time of blue light to solve shadows.

There are several recipes to adjust your print... and a bit YMMV. Learn well Split, it's worth, then compare.

[Greg]

Should I be using green and blue filters instead of yellow and magenta?

Back in the 1990s, I had been using yellow and magenta filters for some years. Then read somewhere that two other colored filters could also be used. Don't remember if they were green and blue, but when I tried using them, I had a terrible time honing in on the print quality that I was used of getting, so went back to using yellow and magenta. I personally don't think which pair of color filters you choose to use all the much matters... choose your pair of color filters and just get in there and print and develop your personal technique.

Still haven't found my notes on split printing.... but did dig up some test prints that I had kept after all these years. Looks like I would make a test print with increased exposures going horizontally with one filter, and then repeat with the other filter but going vertically.

Anybody else split printing this way?

Time to spend some time in the darkroom trying to rediscover the technique that I used back then....

[Steve Sherman]

Steve,
Thanks for the link to your article. I don’t understand the use of green and blue filtration. What kind of enlarger light are you using? I’ve always used yellow filters for low contrast and magenta for high contrast with white light. I have an old Aristo cold light head, and everything I read says I need a 40cc yellow filter to get normal contrast with that head.
I’m trying to come to grips with using VC paper with this head after years of using graded papers. Should I be using green and blue filters instead of yellow and magenta?

Thanks Ben for reaching out with questions. The 40cc filter if memory serves is used to neutralize the w54 Aristo cold light head so that the manufacturers "Subtractive" filter paks can be used to control various grades of contrast with MC papers. All MC papers are designed to react to Green and Blue light, green being used to effect soft contrast while the Blue is used to effect the higher contrast layer of the paper. It's important to note, if you are able to use the Green and Blue gels then printing times will be greatly reduced as this is an "addictive" type of color filtration, essentially the exact opposite of manufacturers contrast filter paks, there are reasons they use the numbered system which is not necessary to go into here. Here is a video from my YouTube channel that describes how MC papers work and also illustrates the various different light sources which can be used to use MC papers. https://www.youtube.com/watch?v=uRlq8CwVvws

Unfortunately, at least on my older Mac computer the color rendering of the Roscoe Blue # 68 and Green # 389 is not accurate on my screen. The Rosco gels are very inexpensive and are used in the Theatre industry to colorize stage lighting. So long as you are able to use the filter "above" the negative to alter the color of the light source there will be no degrading of the enlarged image.

[Steve Sherman]

Back in the 1990s, I had been using yellow and magenta filters for some years. Then read somewhere that two other colored filters could also be used. Don't remember if they were green and blue, but when I tried using them, I had a terrible time honing in on the print quality that I was used of getting, so went back to using yellow and magenta. I personally don't think which pair of color filters you choose to use all the much matters... choose your pair of color filters and just get in there and print and develop your personal technique.

Still haven't found my notes on split printing.... but did dig up some test prints that I had kept after all these years. Looks like I would make a test print with increased exposures going horizontally with one filter, and then repeat with the other filter but going vertically.

Anybody else split printing this way?

Time to spend some time in the darkroom trying to rediscover the technique that I used back then....

Hello Greg, see the above post about Green and Blue filtration and the filters used to affect the maximums of Multi-Contrast paper's design. Feel free to ask further questions.

[Greg]

Hello Greg, see the above post about Green and Blue filtration and the filters used to affect the maximums of Multi-Contrast paper's design. Feel free to ask further questions.

Thanks Steve... The two filters that I tried were definitely Kodak gel cc filters cause I was placing them under the lens. An educated guess after all these years (probably 5% "educated" and 95% "guess"), would be that they probably were too weak of filters to use for this application.

[bob carnie]

It has been found that if you are printing with Ilford filters, using a 0 or 00 is a bad idea when using Ilford Warmtone Glossy paper a slight solarizing will happen, therefore I have always use 1/2 or 1 filter as my soft filter. This is not seen with all prints
but well documented on forums in the past.

[Ben Calwell]

Thanks Ben for reaching out with questions. The 40cc filter if memory serves is used to neutralize the w54 Aristo cold light head so that the manufacturers "Subtractive" filter paks can be used to control various grades of contrast with MC papers. All MC papers are designed to react to Green and Blue light, green being used to effect soft contrast while the Blue is used to effect the higher contrast layer of the paper. It's important to note, if you are able to use the Green and Blue gels then printing times will be greatly reduced as this is an "addictive" type of color filtration, essentially the exact opposite of manufacturers contrast filter paks, there are reasons they use the numbered system which is not necessary to go into here. Here is a video from my YouTube channel that describes how MC papers work and also illustrates the various different light sources which can be used to use MC papers. https://www.youtube.com/watch?v=uRlq8CwVvws
Unfortunately, at least on my older Mac computer the color rendering of the Roscoe Blue # 68 and Green # 389 is not accurate on my screen. The Rosco gels are very inexpensive and are used in the Theatre industry to colorize stage lighting. So long as you are able to use the filter "above" the negative to alter the color of the light source there will be no degrading of the enlarged image.

Thank you, Steve. I'll check out your You Tube videos. I have the really old Aristo cold light head, not the newer V54. I'll play around with some filters and see what happens. Thanks to everyone for some great information and advice. I never used VC papers much, so this will be a learning experience.

[Doremus Scudder]

there seems to be a prevalent misconception that exposing VC paper with separate blue and green sources/filtration is somehow superior to other methods. This is simply not true.

VC paper is sensitive to light from the blue end of the spectrum through the green. It's not sensitive to red light. The blue light exposes the high-contrast parts of the emulsion. The green light exposes the low-contrast parts of the emulsion. Intermediate contrasts are achieved by a mixture of blue and green components.

So (assuming the filters are optimal):

Printing through a deep green filter will give you the lowest possible contrast; it only passes green light.
Printing through a deep yellow filter will give you the lowest possible contrast; it only passes green and red light. The paper doesn't see red.

Printing through a deep blue filter will give you the highest possible contrast; it only passes blue light.
Printing through a deep magenta filter will give you the highest possible contrast; it only passes blue and red light. The paper doesn't see red.

Printing through a filter that passes equal amounts of blue and green light will give you an intermediate contrast.
This applies to separate exposures with green and blue light sources, separate exposures with magenta and yellow light sources (both have red, which the paper doesn't see) and a single exposure through a filter that passes both blue and green light together. Examples of this latter are a #2 Multigrade filter, a dichroic enlarger head set to weak yellow or weak magenta filtration (or no filtration), any CC filtration that doesn't eliminate either blue or green completely, and a single exposure with both green and blue light sources.

Most important. If the paper sees the same amount of green and blue light, regardless of the source, the contrast will be the same. It doesn't matter if it's additive or subtractive, comes together, separately, from filters or LEDs or halogen bulbs or in whatever order. It doesn't matter if the blue component goes through a blue filter or a magenta filter; and it doesn't matter if the green component comes through a green filter or a yellow one or if the colors come form green and blue light sources. Furthermore, the mid-tone separation, the micro-contrast, contrast curves etc., etc., will be the same as well as long as the paper receives the same proportion of green to blue light.

So:
Unless you expose different parts of the print with different filtrations, it doesn't matter a whit how you get the contrast you desire.

Split printing only gives different results from any other kind of printing when one dodges or burns with different filtrations. How you want to achieve that, for the prints that need it, is up to you. There are many different ways but no magic bullets. It's just another tool in the toolbox.

FWIW, there are a whole lot of prints that don't need any fancy split printing...

Best,

Doremus

[Joe O'Hara]

Doremus: The engineer in me appreciates the clarity of your explanation above, which I fully agree with.

If someone is getting results that suggest that something else may be going on, I suspect that there may be a problem with your materials, your technique, or your equipment (or a combination thereof).

[Drew Wiley]

Doremus, VC papers differ somewhat from one another, and more than two emulsions are often involved. The exact image tone as well as behavior of toners can in fact differ somewhat depending on the specific light source or mix thereof. It takes awhile to learn the personality of any given paper. I think you're oversimplifying it somewhat. I don't intend to even begin giving a technical answer. Too many variables. It's a thousand times easier to just do it. And NO, Joe, there isn't any problem with my technique, and certainly not with my equipment. I might be one of the few or perhaps only person on this forum who seriously has ALL of the above options. But I like to skate the ice rink of visual nuances, not formulaic generalities. Quantification will only get you so far. Even the moon landing and return would have been impossible if human eyesight were not involved.

[Ben Calwell]

[QUOTE=FWIW, there are a whole lot of prints that don't need any fancy split printing...

Best,

Doremus[/QUOTE]

Doremus,
I had the same thought and am glad you feel the same.
Ben

[Drew Wiley]

There's nothing fancy about it. Just another tool, but a relevant one. Speaking analogously, an old-fashioned number 2 or 3 nailset might work 80% of the time, but then you've got little finish nails too that warrant a no. 1 in your tool box as well, and at the other end, 60 penny spikes that need something especially big. Depends what you are making.

[cowanw]

Photography was born into an age of both Spiritualism and Empiricism. The power of light, photography, illusion, truth, nature, technology and science were reflective of the cultural changes the nineteenth century experienced.
Peter Henry Emerson espoused the belief that photography was an art and not a mechanical reproduction but the development of sensitometry caused him to recant and restate that photography was a form of mechanical reproduction.
Here we continue the struggle between whether photography obeys the laws of physics and sensitometry in it's response to the wavelengths of light or whether it can be influenced by some magic of alchemy of manipulation.
As far as I know Bob Carnie was the first to report observations of a client of his that there were fundamental differences between the application of Grade Zero green light and Grade 5 blue light compared to a mixture of light at Grade 1 or 1 1/2 and Grade 5 to certain emulsions.
I have too much respect for Bob to ignore his observations of differences depending on the mixture of application of light to certain emulsions. On the other hand I cannot ignore my belief in science, that should prescribe consistency of effects between certain wavelengths of light and certain Silver Halides.
Art versus craft; magic versus science; soft versus sharp; professional versus amateur, there is something for everybody in photography!

[Drew Wiley]

Well, I had three years of organic chemistry, of which 99.9 % has been efficiently forgotten. So that places me squarely back in the realm of alchemy, right where I like it, except with just enough real science retention to know to wear nitrile gloves and use a fume hood! If I can't figure out something intuitively in the darkroom, then I resort to hard research. If I did that all the time, I'd be a geek rather than a printmaker. As far as Bob's observation goes, I've been exploiting certain VC paper idiosyncrasies right along, including the specific one under discussion. I'll let someone else try to explain it chemically. I just wave around some owl entrails at the start of the session, examine the flight patterns of bats and pelicans, then go into the darkroom, and it works! A few test strips tell me the whole story. But one does have to pay their dues and spend some quality time with every specific paper and development and toner combination. Nuance is the name of the game for me.

[Mark Sampson]

Thank God photographic practice cannot be reduced to mere procedure!
If you're careful with your craft, and sensible with your approach, and most of all keep your eyes open, *then* the magic can happen.

[Ben Calwell]

Can’t wait to apply my usual half-assed approach to darkroom science to delve into these mysteries of blue, green, yellow and magenta! I just wish my ancient D2 had a clarity slider adjustment.

[John Layton]

While I do agree that light is light, and color is color...I also feel that the means which I (choose to) use to control these variables indeed affects both how I see and interpret that which I photograph, process, and print.

[Ben Calwell]

While I do agree that light is light, and color is color...I also feel that the means which I (choose to) use to control these variables indeed affects both how I see and interpret that which I photograph, process, and print.

Well said.

[Thom Bennett]

I do a full image test print with the green exposure going across the paper from bottom to top (say 3/6/9/12/15 seconds) and then with the blue exposure from left to right (3/6/9/12/15 seconds). Once the print is processed and fixed I take a look at the squares created and determine which one has the contrast I am looking for and then expose a sheet with that mixture of green and blue (say, 6 seconds of green and 9 of blue). Take a look at that print and then start tweaking. Maybe shave off a certain percentage of green and add a certain percentage of blue. Usually gets me close to the final print fairly quickly. Most dodging will be during the blue exposure and most burning in will be during the green exposure. ymmv.

[MartinP]

Can’t wait to apply my usual half-assed approach to darkroom science to delve into these mysteries of blue, green, yellow and magenta! I just wish my ancient D2 had a clarity slider adjustment.

The clarity adjustment is tweaked via an unsharp-mask, more or less. It should be do-able.

[Doremus Scudder]

Doremus, VC papers differ somewhat from one another, and more than two emulsions are often involved. The exact image tone as well as behavior of toners can in fact differ somewhat depending on the specific light source or mix thereof. It takes awhile to learn the personality of any given paper. I think you're oversimplifying it somewhat. I don't intend to even begin giving a technical answer. Too many variables. It's a thousand times easier to just do it. And NO, Joe, there isn't any problem with my technique, and certainly not with my equipment. I might be one of the few or perhaps only person on this forum who seriously has ALL of the above options. But I like to skate the ice rink of visual nuances, not formulaic generalities. Quantification will only get you so far. Even the moon landing and return would have been impossible if human eyesight were not involved.

Drew,

No argument from me on any of the above! I wasn't addressing nuances, just trying to shoot down the notion that separate green and blue exposures somehow mystically result in better prints than an all-at-once exposure with a color head or multigrade filter.

You'll also notice that I carefully sidestepped the "how many emulsions?" question, mentioning only "components" that were sensitive to blue and green light. We don't need to get into emulsion design to address the OP's concerns and dispel misconceptions. "Oversimplification" here is just avoiding irrelevant details in order to prevent the discussion from going down unnecessary rabbit holes :)

FWIW, I usually like the way some VC (both Foma and MCC-110) papers tone when exposed under higher-contrast settings, so I now have a tendency to skimp on development a bit just to be able to print on the more contrasty part(s) of the emulsion.

One thing I avoided mentioning in my previous post, which may make a slight difference between color head/MG filter exposure and using just a blue/green mix is the Hershel effect. It may be that the red component of the former possibly has an effect on the contrast. I don't think it happens much, if at all, but I've never tested, since it would take a lot more sophisticated spectral analysis than I (or most labs!) have access to.

The theory as accepted states that the emulsion doesn't care how it gets its light or in what order. In order to disprove this, one would need to have different results from, say split printing with green first once and blue first the next time, but keeping the times and intensities the same. I don't believe that happens.

At any rate, the point of my post was simply to emphasize that the real advantage of split printing is to be able to print different parts of the image at different contrasts. If you're not doing that, then any old exposure method will get you the same result as any other.


While I do agree that light is light, and color is color...I also feel that the means which I (choose to) use to control these variables indeed affects both how I see and interpret that which I photograph, process, and print.

Indeed! The choice of method loops with intent and result in a very mysterious way, feeding back on itself so that the end influences the beginning. Still, while this undoubtedly affects the expressive outcome, the underlying physics doesn't change. Choosing the application of the invariables is part of the creative process. All of these possibilities should be open to those just engaging with the craft, like the OP, which was the purpose of my posts.

Best,

Doremus

[cowanw]

These matters came up a while ago and at the time I researched the filters available to (a) pass only blue and (b) block green. It turns out that using blue filters which can be made with very sharp cutoffs (eliminating wavelengths that approach green) is technically better than using magenta filters (subtracting green) since magenta filters have not as sharp a cutoff in those wavelengths that approach green. So blue green enlargers may well achieve a contrastier grade 5. I didn't look at the cutoff frequencies of yellow or green filters but would not be surprised if the similar considerations were true.
Of course this only matters (a) if you have occasion to enlarge using only blue and no green at all or (b) if Bob Carnie's observation, that the order and mix of the various wavelengths, is accurate.

[Drew Wiley]

Doremus - on several occasions I've reversed the sequence of which came first, blue or green, on the same image, same development, and couldn't see any visual difference at all. But what is interesting is that some VC papers need a tad of green light to achieve max contrast & full DMax, while certain other papers can do it using blue alone. The main argument against Y vs M filtration is that older colorheads have often lost a degree of filter efficiency due to a certain amount of spalling off of the dichroic coatings. But with a prime set of filters, I can duplicate results all kinds of ways - true additive BG filtration, under the lens 47blue/61green filter split printing with a V54 cold light, YM colorhead subtractive. Just depends what enlarger I find most useful for the particular image. I do everything 4x5 and smaller on a true additive RGB unit, and all my 8x10's in winter using a cold light - why? Because those two particular enlargers fit under an 8 ft ceiling in a nice little room very well insulated, and very easy to keep cozy in winter (and in our cold coastal summers), while my much bigger additive and subtractive 8x10 color enlargers are in a different room with a high ceiling. I don't really think about it much anymore. It's has all become intuitive. But what I have noticed is how much more responsive current premium VC papers are compared to the old ones.

[koraks]

>But what is interesting is that some VC papers need a tad of green light to achieve max contrast & full DMax, while certain other papers can do it using blue alone.
This is interesting. I was aware of the opposite - that the lowest contrast needs a tad of additional blue in order to reach dmax with most papers. But I didn't know something analogous occurs at the opposite end of the contrast range.

[Doremus Scudder]

Doremus - on several occasions I've reversed the sequence of which came first, blue or green, on the same image, same development, and couldn't see any visual difference at all. But what is interesting is that some VC papers need a tad of green light to achieve max contrast & full DMax, while certain other papers can do it using blue alone. The main argument against Y vs M filtration is that older colorheads have often lost a degree of filter efficiency due to a certain amount of spalling off of the dichroic coatings. But with a prime set of filters, I can duplicate results all kinds of ways - true additive BG filtration, under the lens 47blue/61green filter split printing with a V54 cold light, YM colorhead subtractive. Just depends what enlarger I find most useful for the particular image. I do everything 4x5 and smaller on a true additive RGB unit, and all my 8x10's in winter using a cold light - why? Because those two particular enlargers fit under an 8 ft ceiling in a nice little room very well insulated, and very easy to keep cozy in winter (and in our cold coastal summers), while my much bigger additive and subtractive 8x10 color enlargers are in a different room with a high ceiling. I don't really think about it much anymore. It's has all become intuitive. But what I have noticed is how much more responsive current premium VC papers are compared to the old ones.

Drew,

Yeah, my Chromega heads don't get to the extremes of contrast on either end, but they do the job for 90%+ of my work. For the rest, I've got Wratten #58 and #47 filters. The #47 really gives me a big bump in contrast compared to the 170M on the Chromega E head I use most of the time.

I'm not sure what's functioning with papers that need a bit of green to get to Dmax. Certainly, a print made with both blue and green has more of the emulsion exposed. That would mean, that the prints made on said paper at intermediate contrast settings would have a greater Dmax than those made at the extremes, where less of the overall emulsion gets exposed and subsequently less silver gets developed. Of course, contrast should be appropriately lower. I don't know how adding green would help reach max contrast unless that was directly related to Dmax...

Best,

Doremus

[Delfi_r]

If you have a small part of the silver halide sensible only to green, and another small part sensible only to blue, you need some green light and some blue light to get 100% silver halide exposed. Thus for a maximum Dmax, the copy needs some exposition with an intermediate grade.

Splitgrade makes easy to get the 'grade' where you get maxime value of Dmax without blowing the light parts of the scene. And it's easy to get the optimum value if you expose first the green part and after this the blue part, but it's not mandatory. A friend has made copies professionally with this method in the last 40 years. He's not calling his method splitgrade (perhaps the term was not coined when he learn the technique in UK on the 70')

[Drew Wiley]

With some VC papers it seems necessary for full DMax, not for others. I don't have time to figure out why. I just use a token punch of green as needed. If that's an issue, a tad of Farmers Reducer easily solves any highlight muddying issues.

[bob carnie]

If you have a small part of the silver halide sensible only to green, and another small part sensible only to blue, you need some green light and some blue light to get 100% silver halide exposed. Thus for a maximum Dmax, the copy needs some exposition with an intermediate grade.

Splitgrade makes easy to get the 'grade' where you get maxime value of Dmax without blowing the light parts of the scene. And it's easy to get the optimum value if you expose first the green part and after this the blue part, but it's not mandatory. A friend has made copies professionally with this method in the last 40 years. He's not calling his method splitgrade (perhaps the term was not coined when he learn the technique in UK on the 70')

Split grade become popular when multigrade papers came out in the 90's before that we only had graded papers to choose from
, before that it was SPlit Developers, Contrast Masks , Contour Masks and Pencil work to name a few.

[koraks]

Well, I haven't come across papers that seem to need it; I pront mostly on adox mcc and some fomabrom and fomatone and they seem to achieve dmax with only blue light.
I suppose it depends on the silver load and geain orientarion of the different emulsions. Typically stuff that's not very clearly documented.

[cowanw]

We talk as if the blue and green sensitive emulsions are separate and distinct to help understanding, but they are not.
Take a look at the Ilford site on the first page. The text explains and the graphs illustrate that the papers will achieve maximum black with just blue light as all three emulsions are sensitive to blue light.

https://www.ilfordphoto.com/wp/wp-content/uploads/2017/03/Contrast-control-for-Ilford-Multigrade.pdf

MULTIGRADE papers are coated with an emulsion which is a mixture of three separate emulsions. Each emulsion is a basic blue sensitive emulsion to which is added different amounts of green sensitising dye. Thus, part of the mixed emulsion is sensitive mainly to blue light, part to blue light with some sensitivity to green light and part to both blue and green light. All parts of the emulsion have the same contrast. They also all have the same speed to blue light, but naturally, the part of the emulsion with only a small amount of green sensitising dye has a low speed (that is, is less sensitive) to green light.

[bob carnie]

The Lambda silver gelatin paper, is to my knowledge Ilford Galerie grade 4 emulsion but with an added red sensitivity.. therefore I have to use the paper in total darkness.
So one can start with a harder emulsion, the computer onboard densitometer system adjust to make it work, I think this is why the contrast of these prints are so good.


I first started making silver murals in 2002 using a digital imagesetter (lambda) at that time it was Agfa Classic that I used, four years later the Ilford people introduced their paper , which is what I use today, the only offering change has been adding a matt paper to the mix. I would love to be able to do Ilford Warmtone but they advise it would not work.. The Adox Classic should work as it is basically Agfa Classic ( my understanding) but they do not offer it in 100ft rolls but unfortunately only in 30ft which is useless on the lambda as 1. it curls way too much in the shorter rolls and are impossible to load and unload... I would like to work with Durst technicians to adjust laser intensities to be able to SEE various papers, something I am currently proposing , but each visit is costly as the technician I really like to work with is out of Rochester and it is expensive to bring him in, he is an absolute genius in my eyes.
I believe that with a couple of days of tweaking finding different papers to work would be possible.

[Drew Wiley]

Koraks - Yes, the newer premium VC papers like MCC, MGWT, Cooltone, Berrger, allow native highlight content which early VC papers did not. I have reprinted with ease a number of old negs which gave me hell back in graded and early VC paper days. But I'm not about to abandon any supplementary options in my toolbox which I've acquired over the years if they prove necessary to even better results.