How would I test for this? (split grade printing, hype or real)

[Tom Kershaw]

My MG500 is a mix of equipment. However both head units have the blue / green filter sets. As far as I know I'm the third owner of my De Vere 504 / MG500, originally purchased by the first user in 1996 or thereabouts.

 

[mrosenlof]

Everything I write here is MHO, of course!

I did a fair bit of split grade printing for a couple of years. These days I"m mostly back to single grade printing, but will occasionally burn with a different grade selected. There's no magic, but I found split-grade a reasonable way to land on a reasonable contrast for the overall print. As others have said, it's another tool.

Mostly the reason I've moved away from split grade printing is that I was paying too much attention to the shadows and the highlights. Ya, they're important, but (IMHO again!) the mid tones are mostly where the action is, and that's where I want to (mostly) fix my attention.

 

[warden]

You may be right but in the video I linked to it seems that a single grade did not produce a print that matched the split grade one ...

You may be right when you say I may be right.

These experiments are quite easy and fun to do for those that are already making darkroom prints. Even if you don't end up changing your approach to printing you'll learn something first hand instead of from a video.

Mostly the reason I've moved away from split grade printing is that I was paying too much attention to the shadows and the highlights. Ya, they're important, but (IMHO again!) the mid tones are mostly where the action is, and that's where I want to (mostly) fix my attention.

That's a valid assessment and reason enough for us to do our own experiments and find what works for us. It's easy to get bogged down in the darkroom working on stuff that doesn't really matter.

 

[DREW WILEY]

Blue and green filters are necessarily denser than magenta and yellow, and cause more heat issues.

 

[Lachlan Young]

Oh, yes I did. It is very easy to get good negatives and prints if you use compensating negative developers (such as FX-21). I hardly have to alter contrast at all, and I have a dichroic head. Using Ilford's latest MG (V). You really should not have to alter the paper contrast for most scenes. Some lenses have a bit less brilliance than others, and sometimes you are using a long lens and the image is affected by long distances (dirty air), and sometimes flare affects things. But for the most part, you hardly have to do any manipulation at all. I do "street" photography, and there is usually no time for fancy metering.

Except that FX-21 isn't going to deliver meaningful compensation effects. If it did, it would deliver a curve like XP2.

And most of the time, I don't even need to dodge or burn either. But I'm also printing my own negs.

And that's your prerogative - what you suggest may not be qualitatively right for people who want a negative for active interpretation (or radical re-interpretation) at the printing stage. The OP wasn't asking for an ideological lecture, simply for whether split-grade was going to make much of a difference in learning how to get to a good-enough print faster. The fact that he owns a densitometer gives him the ability to get to the same nominally optimal point that you would via split-grade test strips for grade determination - but with the need to only make an initial test strip for exposure. The resistance that people have to using the best tools for the job (when they are available) in support of learning outcomes is often rather suggestive of their own lack of confidence in their ability to use those tools properly, in my experience.

 

[Doremus Scudder]

I have been split printing now since 1997 when Ilford Warmtone was introduced. I believe there is a difference in quality after thousands of prints.
What I like about low filter and high filter printing is the ability to bring in the delicate highlight details with the lower filter and then with hits of the higher filter bring in the contrast and dmax. There are prints that I have made both ways and with single filter printing I find the dodging and burning much more laborious and in the wrong hands quite visible.
I do not like 0 filter but rather I like to start on a filter that gives me a soft and delicate print based on the Original Scene and the quality of development of the film .

Basically my approach when I split-grade print. Often, though, I'll "single-grade" print and then just use extremes (max M or max Y) for burning.

Doremus

 

[DREW WILEY]

Lachlan - I own multiple densitometers, and sure as heck know how to use them well. But why send someone down that rabbit hole? Even comparing your results to a patch on a calibrated step tablet visually is suitable enough for basic black and white learning. And many of the best printers never even bothered with that.

And incidentally, I was a tool distributor before I retired - the best of the best brands. My own philosophy is, yeah, buy the best tools, but only buy what you actually need.

 

[Doremus Scudder]

And they changed them back again to Y&M with the later MG500 and the MG600 for even better reasons. Ilford quite literally state that the only way to get a genuine G5 is with the G5 filter, which is... magenta - and that the blue dichroic in the older MG500 cannot hit an actual G5. Kodak's data for their papers essentially agrees, though they seem to suggest that the Ilford MG400's magenta dichroic was capable of delivering more contrast than any other filtration system...

Lachlan,

FWIW, I get significantly more contrast out of Ilford MG Classic and other similar papers with a #47B filter than I can get using max M on my Chromega heads. It amounts to 2-3 fewer stripes on the step wedge. I don't know about WT, but the neutral-tone papers I use all seem to respond similarly (Foma 111, Bergger NB).

Best,

Doremus

 

[Lachlan Young]

Lachlan,

FWIW, I get significantly more contrast out of Ilford MG Classic and other similar papers with a #47B filter than I can get using max M on my Chromega heads. It amounts to 2-3 fewer stripes on the step wedge. I don't know about WT, but the neutral-tone papers I use all seem to respond similarly (Foma 111, Bergger NB).

Best,

Doremus

From what I have seen, the Chromega seems to be significantly less able to deliver the highest grades than most other dichroic heads - no idea why.

 

[Augustus Caesar]

Except that FX-21 isn't going to deliver meaningful compensation effects. If it did, it would deliver a curve like XP2.

What? Of course it does!

Paterson 'Acu' Range

Paterson, Chemicals

www.photomemorabilia.co.uk

 

[MattKing]

Mostly the reason I've moved away from split grade printing is that I was paying too much attention to the shadows and the highlights. Ya, they're important, but (IMHO again!) the mid tones are mostly where the action is, and that's where I want to (mostly) fix my attention.

Interesting.
For me, it is almost the reverse.
When I use split grade techniques, which is reasonably frequently, I find that they help me get more easily to the mid-tones I like - which I agree are the tones that matter the most.

 

[DREW WILEY]

Lachlan - older colorheads, including the Chromega, were often less efficient than the later versions. That was true even of Durst. Then you've also got the probability that, over time, the dichroic filter coatings have accumulated grime or even spalled off some of their coating.

But as a matter of principle, subtractive filters can never have the same degree of cutoff as hard additive color separation filters like a 47B or 61 green. How much does that distinction really matter given this topic of attaining maximum VC "grade"? Damn little in my experience.

What I have done with a 47B over the lens to the blue-green cold light was to successfully print negs with no evident silver image at all, and only the pyro stain itself. Why? That's a long story, mostly an experiment. But the prints were full-scale and lovely.

 

[albada]

The kinds of filters likely to be actually used are not going to be equal in density.

Likewise, green and blue LEDs will not be equal in intensity.

Nor are the respective layers of the paper equally sensitive.

Affecting both straight and split exposures equally, and thus will not affect the result of the test.

Therefore some hypothetical LED test is going to be quite misleading.

If straight and split-grade exposures produce equal numbers of green and blue photons (within reciprocity limits), the prints will be identical.
Perhaps someone could ask John Finch to try boosting the contrast of his straight apple print used in his video enough to make it identical to his split-grade print.

Nonetheless, I know split-grade offers two benefits:

1. Many folks find that two test strips with split-grade lead to the final print with less effort.
2. It's the only way to get multiple grades in a print.

Mark

 

[pentaxuser]

Perhaps someone could ask John Finch to try boosting the contrast of his straight apple print used in his video enough to make it identical to his split-grade print.

Mark

Good point but do you know for a fact i.e. you've actually tried this and thereby have produced exactly the same result as you obtained with a split grade print?

Essentially we are back to my original question which was: Is it as simple as this and can it only be done by fractions of a grade of me or less than the grade that MG filters provide. This is what I have yet to see done Everyone makes videos showing split grade is done and why it has benefits per se, including Ilford Master Printers and yet despite the not insubstantial number of contrary views that it confers no benefits no-one seems to have grasped the nettle and made a video that proves it confers no benefit

I should add that when I say "no benefits" I am not referring to the 2 you mention but no benefits in a best "straight" print v a slit grade one with fractions of a grade

You'd think that in advocating the advantages someone would at least have seized on the "less effort" benefit

pentaxuser

 

[Sirius Glass]

Good point but do you know for a fact i.e. you've actually tried this and thereby have produced exactly the same result as you obtained with a split grade print?

Essentially we are back to my original question which was: Is it as simple as this and can it only be done by fractions of a grade of me or less than the grade that MG filters provide. This is what I have yet to see done Everyone makes videos showing split grade is done and why it has benefits per se, including Ilford Master Printers and yet despite the not insubstantial number of contrary views that it confers no benefits no-one seems to have grasped the nettle and made a video that proves it confers no benefit

I should add that when I say "no benefits" I am not referring to the 2 you mention but no benefits in a best "straight" print v a slit grade one with fractions of a grade

You'd think that in advocating the advantages someone would at least have seized on the "less effort" benefit

pentaxuser

What I typically see is that the contrast of the darker areas and the highlights are increased when compared to a single grade print.

 

[albada]

[...] no-one seems to have grasped the nettle and made a video that proves it confers no benefit

By proof, I think you mean a demonstration of making a split-grade print, and then making a monograde print that's identical. I think such a proof would be weak because somebody could always reply, "It worked for that example, but there are other examples that cannot by replicated with monograde." (I just invented the term "monograde"). So the best we can do is provide a mathematical proof, which I'll do below.

To avoid bothering with convolution of differing unknown spectra, let's assume the paper responds to exactly one wavelength each of green and blue.​

For any split-grade print, let tg = green exposure time in stops, ig = green light-intensity in stops.​

Likewise define tb and ib for blue.​

Let d = tb - tg​

Let tb' = tb - d = tg​

Let ib' = ib + d​

We have reduced blue time by d stops, and increased blue intensity by d stops, resulting in the same blue energy impinging on the paper.​

Thus, exposures (tb,ib) and (tb',ib') will produce identical results, within reciprocity limits.​

But tb' = tg, so the split exposures of (tg,ig) and (tb',ib') have the same time, and thus can occur simultaneously, which is a monograde exposure.​

Therefore, any split-grade print can be changed into an equivalent monograde print.​

BTW, a PM pointed out to me that my statement that "it's the only way to get multiple grades in a print" was wrong. Here's another way to get multiple grades on the same print: You could print a landscape at grade 2, and burn the clouds with a grade 5 filter, and now you have two grades on the print.

Mark

 

[MattKing]

BTW, a PM pointed out to me that my statement that "it's the only way to get multiple grades in a print" was wrong. Here's another way to get multiple grades on the same print: You could print a landscape at grade 2, and burn the clouds with a grade 5 filter, and now you have two grades on the print.

FWIW, I consider that latter example to be split-grade printing - more limited than applying the full technique, but still split-grade.

 

[Lachlan Young]

But tb' = tg, so the split exposures of (tg,ig) and (tb',ib') have the same time, and thus can occur simultaneously, which is a monograde exposure.Therefore, any split-grade print can be changed into an equivalent monograde print.

We're also 3 pages in and no one has noticed that the Ilford MG400 and MG500 are operating as split-grade integrated into an effective single-grade equivalent...

There's also probably a likelihood that many people using split-grade end up printing an effective 1/2 grade+ harder than they might have gone to if they printed using a single grade exposure and their socially conditioned understanding.

older colorheads, including the Chromega, were often less efficient than the later versions.

I don't think it's that. I suspect it has a lot more to do with the range of colour materials they were expected to handle, with the UK/ Euro heads needing to handle professional/ industrial/ institutional markets that used an array of Agfa-system materials, some still unmasked, alongside Kodak - whereas the US heads were possibly aimed more at a marketplace that was heavily (totally) dominated by Kodak materials. Given De Vere's ties with Rodenstock (the condenser system in the 504 used Rodenstock optics) for example - and Durst's to Schneider, ready access to a choice of suitable dichroic filters will not have been a problem. It will have been similar with Omega, which really suggests it was an intentional choice for the (still somewhat regional) markets they served at the turn of the 1960s into the 1970s. And once large-scale/ institutional users got used to a particular system, upgrading/ changing it will have been hard to implement.

 

[pentaxuser]

There's also probably a likelihood that many people using split-grade end up printing an effective 1/2 grade+ harder than they might have gone to if they printed using a single grade exposure and their socially conditioned understanding.

Can you expand on what you mean by socially conditioned understanding?

Thanks

pentaxuser

 

[DREW WILEY]

Lachlan - I was told of a tightening of the bandpass width of even Durst dichroic filters by someone who specialized in repairing their commercial enlargers. I suspect it happened in the early 70's, and Omega followed suit. But there is a real secondary issue, and that is simply that a lot of older colorheads don't have filters in particularly good shape - either they have accumulated grime and never been cleaned, or have actually spalled off some of their coating due to too much cumulative heat.

The difference in look - contrast and hue saturation - between my old Chromega (with filters in fine condition) and my newer additive heads was so dramatic that in cases you'd think the color shots were different to begin with. Even the masking had to be done differently. But the distinction between these additive heads and my somewhat later Durst CMY 10X10 head is relatively minor.

The big labs around here were a mix of Omega D (4X5) and F (8X10), with plenty of big expensive commercial Dursts too, sometimes even a big Devere thrown in for mural work. Film itself routinely available in the area included not only Kodak's selection, but Agfa and Fuji too. They were expected to competently handle it all. I did my own color printing, including some old pre-E6 highly contrasty Agfachrome 50, as well as very soft Agfachrome 1000 - a lovely film I wish was still around.

Toward the end, Durst actually switched their latest 2000W heads to narrow-band RGB additive; but then they closed their entire commercial division before those ever went to market. They did end up in a Gov facility, but not on Durst L chassis. Terrible heat issues with short filter life. I took a different route and used sandwich style dual cutoff filters to achieve true RGB, with a split V-head to dramatically improve cooling. There the problem is the really big size and weight of the head, needing an exceptionally solid custom chassis, along with more complicated electronics. The look in print is a little more contrasty with cleaner hues than any CMY subtractive colorhead. If I need to dial that back a little, I just substitute ordinary enlarger lenses for the fancy apo ones.

But my additive heads do make black and white VC split grade printing really pushbutton simple if I opt to go that route, blue channel versus green channel.

 

[Milpool]

We're also 3 pages in and no one has noticed that the Ilford MG400 and MG500 are operating as split-grade integrated into an effective single-grade equivalent...

Indeed. There’s probably some general confusion regarding how dichroic heads (or at least most of them) work. It’s basically two filters (max contrast/min contrast) in the light path to the mixing box and the relative amount of one filter to the other in the light path is what you are controlling with the dial(s). It’s “split grade” in one exposure - which is the same as using an intermediate filter. People claiming split grade does anything special are trying to sell you on something and/or don’t understand how light/VC papers work.

 

[DREW WILEY]

Milpool - in terms of conventional colorheads, if desired you can simply ratchet either M or Y all the way up by themselves to achieve something approximating true split grade printing. That's not entirely sharp-cutting, since a bit of "white" light spillover is always present in subtractive CMY systems; but for all practical purposes, it's good enough. Or one could just stick with white light and use a deep green versus deep blue filter over the lens instead.

The vast majority of my own negs are tame enough to just need a little bit of tweaking up or down in terms of contrast change, if I need any shift in the light color at all. But it can be helpful to at least experiment with split printing just for sake of yet another potentially useful tool in your tool box.

I can't comment on what goes on inside the various Ilford dedicated VC heads. But if two independent controls are involved, it seems one would be able to use the two colors of light selectively, and not necessarily mixed. Even with my V54 blue-green cold light I can cleanly separate the two respective colors by using appropriate colored filters over the lens itself.

 

[Milpool]

Well, really the maximum and minimum contrast available for a given paper will be determined by the pass band characteristics of the filters. CMY or RGB in and of itself makes no difference - for any incandescent light source it’s always subtractive whether you see CMY or RGB on the easel.

 

[DREW WILEY]

You clearly do not understand the significant difference, Milpool. Take any two true RGB color separation filters and put them together, viewing a strong light source, natural or artificial full-spectrum, and the result is almost black. I've even viewed solar eclipses that way. But take the strongest magenta and yellow filters you can find, do the same thing, and you'll see that a fair amount of residual white light still gets through.

Do the same thing looking a something bright red. With either a nearly pure green 61 filter of 47 or 47B blue, that red object will look black. But if you look at it with either a yellow or magenta filter, you'll still discern the red color. One catergory of filters is truly sharp-cutting; the other is not. No, VC papers are not sensitive to red light, but this does prove how some white light is getting through in
either case subtractively, whether Y or M, containing some of both blue and green as well as red.

Yes, you can go either way in terms of VC paper printing. Magenta subtracts green light, while yellow subtracts blue; but the effect can never be as downright intense as full true green versus full true blue. Color theory 101.

I don't want to press this fact too hard in the present context, because one rarely needs to go to those extremes with today's excellent VC papers unless they're dealing with really bad negatives to begin with, needing a lot of "salvage" printing. But there is a significant difference between additive and subtractive light in principle per se.

And there are times one basically just wants to print VC using ordinary enlarger light, but then add a little selective punch to one of the extremes exclusively. True additive G versus B filters do a better job of that.

 

[pentaxuser]

By proof, I think you mean a demonstration of making a split-grade print, and then making a monograde print that's identical. I think such a proof would be weak because somebody could always reply, "It worked for that example, but there are other examples that cannot by replicated with monograde." (I just invented the term "monograde"). So the best we can do is provide a mathematical proof, which I'll do below.

To avoid bothering with convolution of differing unknown spectra, let's assume the paper responds to exactly one wavelength each of green and blue.​

For any split-grade print, let tg = green exposure time in stops, ig = green light-intensity in stops.​

Likewise define tb and ib for blue.​

Let d = tb - tg​

Let tb' = tb - d = tg​

Let ib' = ib + d​

We have reduced blue time by d stops, and increased blue intensity by d stops, resulting in the same blue energy impinging on the paper.​

Thus, exposures (tb,ib) and (tb',ib') will produce identical results, within reciprocity limits.​

But tb' = tg, so the split exposures of (tg,ig) and (tb',ib') have the same time, and thus can occur simultaneously, which is a monograde exposure.​

Therefore, any split-grade print can be changed into an equivalent monograde print.​

BTW, a PM pointed out to me that my statement that "it's the only way to get multiple grades in a print" was wrong. Here's another way to get multiple grades on the same print: You could print a landscape at grade 2, and burn the clouds with a grade 5 filter, and now you have two grades on the print.

Mark

Thanks for that proof, The algebraic notation made my head spin a bit and I am not sure if I understood all of it so I need to ask some questions:

What does d represent and likewise what is tb'? Clearly in your proof intensity of the green and blue are important as well green exposure, Am I correct in assuming that the effect of blue exposure on the print is the sum of tb+ib and likewise that of the effect of green exposure is tg + ig?

What it seems is that we arrive at a kind of zero sum proof that says that whatever we arrive at in terms of the combined exposure of say grade 0 and 5 ( the split grade ) to get the best print, it is replicated by a single grade exposure at some whole number of grade plus a part of that grade number( let's call that the single grade print) that will give exactly the same print. Any one part of the split grade print will give the same reading on a densitometer as it would on the single grade print

I must admit that in stating what I think is the mathematical proof that you provide of my above statement my brain still has difficulties in quite grasping it but that could be my fault However what my brain can accept is that provided there are no flaws in your proof or any of the premises of your proof such as the effect of blue and green not being confined to defined layers of only blue or green then I do not agree that someone saying:" well it may have worked for that print but will not necessarily for others" amounts to a weak proof. Rather it has to their brain that's weak in that case as might be the case with me , although I like to think that I remain agnostic as opposed to committed believer or non believer in the "intrinsic" improvement of split grade

If you've seen the video what I am about to say is redundant but if not then between mins 16-17 he states that his single grade print was grade 3 which he had produced in his previous video. So might half a grade to 3.5 made it the same as his split grade?

pentaxuser