Split grade printing - technical analysis?

[tih]

I've been reading about split grade printing, and I've watched a few Youtube videos, but I've not been able to find anyone who actually provides technical details of what happens during this process. I use the RH Analyser, and it lets me place the highlights and shadows where I want them, and it tells me how to achieve that using a specific filter grade and exposure. Is split grade printing any different in this respect, or does it only offer grades in between the .5 steps that my filters give?

Of course, I understand that dodging and burning during one of the two split grade exposures will alter the contrast in the affected area of the print - but people seem to be saying that just basic full image exposure using split grade can give results that cannot be achieved using a single filter, even if that filter is dialed in on a continuous scale using a colour head. Is this true?

I'd really like to read a thorough technical description of what's really going on here.

 

[Nicholas Lindan]

The following may be a help:
http://www.darkroomautomation.com/support/appnotesgmeasured.pdf
http://www.darkroomautomation.com/support/appnotevcworkings.pdf

I don't know of any blind evaluation studies of finished prints that demonstrate a difference between graded filters and split grade. Some people prefer split grade, some VC filters. See which method fits you the best.

 

[cramej]

Split grade printing uses two or more VC graded filters.

For example, I have scene that I want to make high contrast or dramatic but not completely wipe out the highlights. I can make part of the total exposure with. 4 or 5 filter to get maximum blacks where I want to and then use a 0 or 2 to bring the highlights back down while not affecting the already exposed dark areas as much.

 

[Pieter12]

Split grade is sort of can acquired taste. Some use it only for problem negatives, some use it all the time. It kind of depends on what you learn and are good at. I like the fact that my split-grade test prints give me an idea of what to expect and how much to burn or dodge the final print.

 

[Andrew O'Neill]

Not much on the net that's technical, but the links that Nicholas posted are a good start.

 

[Frank53]

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.

 

[grain elevator]

people seem to be saying that just basic full image exposure using split grade can give results that cannot be achieved using a single filter, even if that filter is dialed in on a continuous scale using a colour head. Is this true?

No. VC paper has two (or more) emulsions with different contrast, sensitised to different wavelengths. Whether one exposes both at the same time, with light of mixed colour, or at different times, with light of fairly clean colour that (more or less) only affects one of the emulsions respectively, cannot possibly make a difference.

 

[MattKing]

No. VC paper has two (or more) emulsions with different contrast, sensitised to different wavelengths. Whether one exposes both at the same time, with light if mixed colour, or at different times, with light of fairly clean colour that (more or less) only affects one of the emulsions respectively, cannot possibly make a difference.

Actually, the two (or more) emulsions exhibit the same contrast behavior.
They differ in their sensitivity.
The end result in your print is determined by how the exposures add together - it is a cumulative result.
If relatively speaking you have lots of exposure to the less sensitive, green sensitive emulsion, and relatively little exposure to the more sensitive, blue sensitive emulsion, the resulting print will have shadows that are relatively light in tone, resulting in a print that is lower in contrast.
However, if relatively speaking you have lots of exposure to the more sensitive, green sensitive emulsion, and relatively little exposure to the less sensitive, blue sensitive emulsion, the resulting print will have shadows that are relatively dark in tone, resulting in a print that is higher in contrast.
But that is more about how the sausage is made - what the OP asked for - not about the easiest way to think about split grade printing.

 

[Lachlan Young]

I use the RH Analyser, and it lets me place the highlights and shadows where I want them, and it tells me how to achieve that using a specific filter grade and exposure. Is split grade printing any different in this respect, or does it only offer grades in between the .5 steps that my filters give?

Of course, I understand that dodging and burning during one of the two split grade exposures will alter the contrast in the affected area of the print - but people seem to be saying that just basic full image exposure using split grade can give results that cannot be achieved using a single filter, even if that filter is dialed in on a continuous scale using a colour head. Is this true?

Without dodging & burning during the two exposures, there is nothing that split-grade offers other than potentially tighter control of absolute grade used - and the reality is that anything under 1/4-1/2 grade difference is very unlikely to be noticeable. The analyser systems attempt to understand the density range of the negative and to place the desired highlight/ shadow on the optimal exposure scale of a particular paper emulsion - which may differ from the absolute grade numbers used - ie 'G2' on some papers may be closer to 'G1' on another in absolute exposure scale terms. Too often people get bogged down by making micro-refinements that make no observable difference whatsoever, rather than shifting up or down by at least 1/2 grade and/ or a meaningful amount of exposure (thinking in f-stops makes a huge difference here). At some point, everyone needs to learn that there is no 'perfect' grade and that they will need to dodge/ burn (at different grades if so desired) - you need to interlink the desired aesthetic end result with the most direct route to it and stop worrying about if you got the 'correct' grade.

 

[Craig75]

I would have thought split grade would give a slightly different look to a straight grade print just because of way it works.

Easiest way would just check what's happening by split printing a wedge and comparing it to straight grade prints.

Not a way of printing I've ever had much joy with

 

[mshchem]

I've had negatives that split grade exposures made a big impact, so much so that I thought, man I should do this all the time. I've found that it depends on the negative. Same can be said for exposure at a set contrast. Until I have made several different prints to compare it's hard for me to be sure.

 

[Old_Dick]

I like Lina.

 

[ic-racer]

With split grade printing it would seem dodging and burning are going to be more complicated, as you might have to re-do everything twice, however, you really only need to dodge during the blue exposure and burn during the green exposure.

 

[Pieter12]

Without burning/dodging during the individual exposures, and assuming continuously variable filtration (or close enough such as half grades), “split grade” does nothing from a tone reproduction perspective which cannot be achieved with a single exposure.

OP asked for a proper analysis. This was done by Dickerson/Zawadzki and presented in an article in the Jan/Feb 2009 issue of Photo Techniques magazine.

That would be the analysis to look for online or elsewhere if you can find it. I’ve since thrown away my paper copies, unfortunately.

To me, it seems that dodging and burning during the individual exposures is the main advantage of split-grade printing, plus the fact that it frees you from the need to determine the overall grade to print at. It is pretty much the only technique I use now.

 

[Craig75]

Did that. No difference.

I would have thought it would be a grade 0 print with some very minor extra density in deepest shadows.

So there should be a slight bump in shadow density which would make it different from a straight grade 0 print. Whether that bump would be measurable by human eye is a different matter though. That would be my understanding anyway.

What did you see when you split the wedge? What approximate grade did it come out at? (Obviously a few variables here)

I'm not convinced by it as a technique but did see Ilford have a video on it and lina bessanova whose prints and videos I like but I avoided watching them for fear of getting sucked into a hole.

 

[MattKing]

I find it remarkably revealing when I perform the following demonstration:
1) Through usual methods I arrive at a fully satisfactory print I like using split grade techniques - one exposure through a yellow (or green) filter, and then another exposure through a magenta (or blue) filter.
2) Then I do two additional prints. One using the same yellow (or green) filter, using the same exposure exposure through that filter I used for the fully satisfactory print. And then one exposure through the same magenta (or blue) filter, using the same exposure exposure through that filter I used for the fully satisfactory print.
The two resulting subsequent prints are really interesting. In almost all cases, almost all of the image in the fully satisfactory print comes from the exposure through the yellow (or green) filter. The image that comes from using the magenta (or blue) filter adds relatively little, but that image is critical to the apparent contrast and depth of the final result.

 

[grain elevator]

How is what you just described possible if the two emulsions have the same contrast behaviour?

 

[tih]

The following may be a help:
http://www.darkroomautomation.com/support/appnotesgmeasured.pdf
http://www.darkroomautomation.com/support/appnotevcworkings.pdf

Thanks, Nicholas - that's very interesting, indeed, as is the other material you publish on your web site.

OP asked for a proper analysis. This was done by Dickerson/Zawadzki and presented in an article in the Jan/Feb 2009 issue of Photo Techniques magazine.

I haven't been able to track that article down, but it finally occurred to me that I probably had something in my library, in Ralph Lambrecht's wonderful book "Way Beyond Monochrome". Sure enough, he has two chapters on split grade printing; one explaining the basic how and why of it, very clearly, and with good graphs and examples, and one showing how to use dodging and burning at the two filtrations to manipulate local contrast, again with excellent examples. Should have thought of checking that book in the first place.

Now, as I mentioned, I have the RH Analyser Pro, and it seems to me that its primary function is to give you a fast path to the equivalent of the basic two exposure split grade process. You do, however, lose the ability to selectively dodge and burn at extreme filtrations during the primary exposure, since the Analyser produces the result using a single exposure. I suspect that my main take-away from this will be the idea that I can, in addition to dodging and burning at the filtration the Analyser helps me find, top this off by doing extra burning, using filter grade 5, to boost local contrast in selected areas of the print by darkening shadows there. I'm looking forward to experimenting with this!

 

[tih]

How is what you just described possible if the two emulsions have the same contrast behaviour?

You can see that clearly in the graphs in the paper Nicholas Lindan linked to: http://www.darkroomautomation.com/support/appnotevcworkings.pdf

 

[Kilgallb]

I asked Ilford how VC paper works and got this reply.


For split grade printing, most people use grade 00 (or 0) and 5 filters. ie the extreme filters in our kits. 00 (or 0) being what will give softest contrast - and 5 giving the hardest contrast.
Filter 00 (or 0) is yellow. Grade 5 is a strong magenta.
Inbetween these, the other filters are a variety of less magenta as the filters back off from 5, to stronger yellow/orange colourations as the filters move up from 00.

So - referring back to your other comments re how the paper responds etc, you likely know most of the below - but hopefully it can still be a helpful recap for you.....
Multigrade is coated using 3 separate emulsions. Each emulsion is a basic blue emulsion - to which we add different amounts of sensitising dyes.
The emulsions are blue sensitive with a slight sensitivity to green light - such that part of the emulsion is sensitive mainly to blue light, part to blue with some sensitivity to green light, and part to both blue and green light.

All 3 parts of the emulsion have the same contrast. They also all have the same speed to blue light, but the part of the emulsion with only a small amount of green sensitising dye has a low speed and is thus less sensitive to green light.

When the paper is exposed to blue light, all parts of the emulsion react and contribute to the final image. This image is high contrast - because of the additive effect produced by the 3 emulsions with the same speed and contrast.

When the paper is exposed to green light, only the parts of the emulsion with the larger amounts of green sensitising dye react initially. This is because the 3 emulsions have very different sensitivities to green light.

By varying the proportions of blue to green light, a contrast range between these 2 extremes can be obtained. The simplest way to control the colour of the light reaching the emulsion -during exposure is by the use of filters.
A magenta filter absorbs green light and transmits blue.
A yellow filter absorbs blue light and transmits green.
So in this way - by using the full range of filters in kits - high, normal and low contrast images can be made.n

 

[radiant]

One advantage in using two filters for one print is to control contrast more accurately ("half" grade steps vs. linear with two filters). Does one need such accuracy? That is another discussion

When doing two filter exposures (00 + 5) I think most analyze more carefully what the outcome is. While technically there isn't any difference, it might make us work differently and maybe more accurately.

Not to mention the benefits of split grade dodging & burning ..

 

[RalphLambrecht]

I've been reading about split grade printing, and I've watched a few Youtube videos, but I've not been able to find anyone who actually provides technical details of what happens during this process. I use the RH Analyser, and it lets me place the highlights and shadows where I want them, and it tells me how to achieve that using a specific filter grade and exposure. Is split grade printing any different in this respect, or does it only offer grades in between the .5 steps that my filters give?

Of course, I understand that dodging and burning during one of the two split grade exposures will alter the contrast in the affected area of the print - but people seem to be saying that just basic full image exposure using split grade can give results that cannot be achieved using a single filter, even if that filter is dialed in on a continuous scale using a colour head. Is this true?

I'd really like to read a thorough technical description of what's really going on here.

unless you are dodging or burning during one of the split-grade exposures,split-grade will not give you a print any different from a single filtration exposure!

 

[grain elevator]

This image is high contrast - because of the additive effect produced by the 3 emulsions with the same speed and contrast.

Ah that explains it. Thank you!

 

[radiant]

unless you are dodging or burning during one of the split-grade exposures,split-grade will not give you a print any different from a single filtration exposure!

That is wrong. You can get more grades or portable grade adjustment in between with two filter method.

 

[removed account4]

there 's a little info here: https://www.lesmcleanphotography.com/articles.php?page=full&article=21