Split grade printing with RH Designs Analyser

Does anyone have a reliable technique for split grade printing with the Analyser?

Yes, I know that theoretically the analyser does away with the need to split grade print, but some negatives are tricky and would definitely benefit from the increased control. When I tried, I found it easy to find the soft grade by taking a highlight reading, then running a test strip around that value to fine-tune it. When I did the same with the shadow reading, the print looked very dark, most likely because the two exposures were adding up to too much.

Wondering if there’s a simple technique that anyone is already using, such as reducing the shadow reading by a stop for example? Just something to get within the right ballpark for an accurate test strip.

The gray scale on the analyzer tells you your density differences and in most cases gives you a grade that would reproduce all those tones. But as you state we like to shift the tones sometimes to darker or lighter. Think of using it like you would under lens filters. You would first measure density or do a test strip then pick a time for a soft grade 00 and a time for a hard grade 5 and adjust as needed. With the analyzer you already know your densities in certain areas and can shift those values on the gray scale by changing time or grade.

So if the analyzer suggest grade 3 @ 16seconds you have some options. example Change the settings to grade 2 for 2 seconds and do 5 exposures (total 10Sec) Then change the grade to 5 and do 3 2second exposures for a total of 16 seconds. Or 6 sec grade 2 + 10 sec grade 5. Dodging during desired grades.

Or you can use their burn/difference mode to merely add exposure to the base exposure at a different grade. I would typically start a 1/2 grade lower for the full 16second exposure - then ADD (BURN) hard filter for up to 1 stop more using increments of 1/4 stop or 4 seconds.
Even with just blue and green light from the ilford 500H you can still do this but it gets a little challenging mentally. 16secs @ grade 3 = head exposes Xtime green + Ytime blue - Difference mode - add 4 seconds (20 is displayed) and change grade to 5. expose, expose, expose...

experience will teach how to expand/contract tonal values - you can get there a bit quicker if you use a step wedge and visually see the density changes imposed by split grade printing since you will not be dodging anything. First measure your negative to see its density values - then mark/use only those areas on the step wedge that correspond. Your step wedge prints will show you how much variance the time/grade adjustments make.

All of this assumes you have calibrated the analyzer settings to your paper and developer. I find that Ilford MGFB classic required 1/2 stop more than the analyzers default settings at grades 2 and 3 with 1 stop more for grades 4 and 5. I have yet to make the 20 step grey scale but that is on my to-do list this summer.

Just to make the point that the Grade 2 or 2.5 combination may not be the equivalent of equal exposures of blue and green. My Zone vi enlarger is comparable at grade 2 of Ilford under lens filters as equal to 22% blue exposure and 78% green exposure.
My suggestion would be to use a step tablet (or any negative you choose) and expose it at each grade of combined light, recording time, and then recreate the print with split light, recording new times for each. Then you would have a table of conversion. ie your analyser says grade three at 14 seconds; consult your table and you divide the time between blue and green as per the percentages you have tested to work.
Hint, blue is way more powerful than green (4:1 in my system)

Just to be clear what type of split grade printing I'm referring to: it is where you first determine the exposure for the highlight density required (usually with a grade 00 filter), followed by the shadow detail using grade 5. In the past I've used trial and error to determine the exposure times for a test strip, but obviously it would be great if the Analyser could help out. It's very easy to get started with the soft grade, but it's the hard grade for shadow details I'm struggling with. When I tried it, the hard test strip was much too dense.

esearing said:

The gray scale on the analyzer tells you your density differences and in most cases gives you a grade that would reproduce all those tones. But as you state we like to shift the tones sometimes to darker or lighter. Think of using it like you would under lens filters. You would first measure density or do a test strip then pick a time for a soft grade 00 and a time for a hard grade 5 and adjust as needed. With the analyzer you already know your densities in certain areas and can shift those values on the gray scale by changing time or grade.

So if the analyzer suggest grade 3 @ 16seconds you have some options. example Change the settings to grade 2 for 2 seconds and do 5 exposures (total 10Sec) Then change the grade to 5 and do 3 2second exposures for a total of 16 seconds. Or 6 sec grade 2 + 10 sec grade 5. Dodging during desired grades.

Or you can use their burn/difference mode to merely add exposure to the base exposure at a different grade. I would typically start a 1/2 grade lower for the full 16second exposure - then ADD (BURN) hard filter for up to 1 stop more using increments of 1/4 stop or 4 seconds.
Even with just blue and green light from the ilford 500H you can still do this but it gets a little challenging mentally. 16secs @ grade 3 = head exposes Xtime green + Ytime blue - Difference mode - add 4 seconds (20 is displayed) and change grade to 5. expose, expose, expose...

experience will teach how to expand/contract tonal values - you can get there a bit quicker if you use a step wedge and visually see the density changes imposed by split grade printing since you will not be dodging anything. First measure your negative to see its density values - then mark/use only those areas on the step wedge that correspond. Your step wedge prints will show you how much variance the time/grade adjustments make.

All of this assumes you have calibrated the analyzer settings to your paper and developer. I find that Ilford MGFB classic required 1/2 stop more than the analyzers default settings at grades 2 and 3 with 1 stop more for grades 4 and 5. I have yet to make the 20 step grey scale but that is on my to-do list this summer.

Click to expand...

Thanks Eric - I think the answer is I'm going to have to work this out via a bit of trial and error. I'm not sure whether it's possible to determine a 'simple rule' that will give a good starting point for the shadow test strip, but if I work something out I'll post it back here.

I had thought that RH Designs in its literature had given a way of split grade printing but as you say RH Designs see little point in it. It would seem to be covered in section 13.2 "Burning in at a different grade" where an example of burning in a sky where the first exposure for the whole print was grade 4 but this has left the sky as a pale grey and improvement can be obtained with additional burning but at say Grade 1

These were issue 14 instructions, May 2007

pentaxuser

Another thought - but haven't tried it yet. You can do this as an exercise without actually printing to see how the meter reacts to known/expected values.

Using a step tablet negative measure the middle grey and adjust the time until it is in the middle gray portion of the gray scale of the analyzer. IE 16 sec Grade 2.5
measure a point 3 stops darker. That should show an area on the gray scale near the white end. repeat for 3 stops lighter and see indicator at dark end.
- you can now measure points in between for reference on your gray scale.
Now adjust the grade to 0 or 00 and watch the movement of indicators along the gray scale, change time if necessary until white is at first step on the grayscale, note the time (min time)
Your indicators should be at near white to mid dark grey (low contrast)
Now using only time change, shift your indicators toward the almost black end - note the time
The black end time is the max time you would apply with 00+5 exposure. It is how much time the meter says you need to get dark tones to near black.

If your 00 min-time was 12 seconds and your max time is 24 seconds - try grade 00 12sec and grade 5 at 12 sec
In theory your first exposure sets your highlight region with minimal contrast and the second exposure works to deepen the mid to dark tones without much impact to highlights because the blue light affects the darker tones more quickly.
In practice you will need to adjust time for grade 5 to control the dark tones. If your enlarger uses separate bulbs like the ilford 500H bulb strength is also a factor as is the filter strength (usually requires 1 stop more on VC head for grades 4 or 5).
If you need more highlight definition adjust grade 00 to 1 or 2, and note the indicator positions and new min-time. A pre-flash can do this for you too since it sets the minimum exposure before the highlight tones
The layers of light sensitivity in your paper also come into play since the paper may lean more blue sensitive or green sensitive or even have mid levels of sensitivity. Warm tone paper is slower than normal/cold tone papers.
And of course developer choice and dilution and development time also factor in. LPD at 1:4 behaves differently than Ansco 130 at 1:1.

now think of scenes with mostly light tones vs scenes with mostly dark tones. If you use only the portion of the step wedge that corresponds, how does that translate and how much would you want to contract/expand the tones?

I abandoned split-grade printing for a while because using the Analyser makes things so easy. However, I recently came across a couple of negatives which were hard to print (shadows were compressed to black at a grade that produced nice bright highlights), so a circled back to split-grade, using the analyser as a starting point for the highlight and shadow exposures. Here's an example of what I've been doing:

Highlight test strip (left image below)
1. Use the Analyser to take a highlight and shadow reading, as normal
2. Set the grade to 00 and move the highlight to the left
3. The time shown is the starting point for the highlight test strip (39.8 seconds)

Shadow test strip (right image)
1. Notice that at grade 00 (left image), the shadows will be 7 steps too light, according to the meter. Therefore we need to add seven steps of tone to make the shadows dark enough after they have received the grade 00 exposure.
2. Without making any other changes, or taking other readings, change to grade to 5 on the analyser and change the time so the shadow reading sits on the 7th step from the left (right image)
3. The time shown is the starting point for the shadow test strip (45 seconds)



I have absolutely no idea whether I'm doing the 'right thing' here, but I've tested this with three or four tricky negatives, and it's giving me a great starting point for my test strips. Less wasted paper, less wasted time

I ran a test with the negative used in the above example and the Analyser suggested it should be printed for 64.9 seconds at grade 3. This produced a print which was superficially very similar to my split-grade version, but on close inspection you can see the split-grade version has quite a bit more shadow detail and very slightly more highlight detail. I agree with the theory that anything you can split grade print can be printed with a single grade and time, but I think that assumes filters are almost infinitely variable, whereas in the real world you have to jump between full half-grades. Split-grade printing with an Analyser provides 12th of a stop test strips which provide finer steps than between half-grade filters. Yes, I could use the filters in my colour head for much finer control, but they get really fiddly, even with normal half grade steps and more importantly, the Analyser doesn't support anything finer than standard half grades.

Anyway, give it a try if you have an Analyser and a tough negative, and let me know how you get on.

The single biggest problem from my perspective with these systems is their insistence on giving the low contrast exposure first - better to set the shadow/ mid values, then bring in highlights - at least that's what I've found.

FujiLove said:

I abandoned split-grade printing for a while because using the Analyser makes things so easy. However, I recently came across a couple of negatives which were hard to print

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The analyzer is fantastic, but's a tool, not always direct solution !

In the way you adjust split grade you place highlights and shadows where you want, but this may not deliver the tonal range and gradient you want for the mids, and mids often are the priority.

So IMO that way may work but not always. Another approach is solvinng grade_exposure for the mids and later finding the way to fit shadows and highlights like you can, deformating the paper curve to an S can be required, but this requires an additional effort, and it can be complex.

Lachlan Young said:

The single biggest problem from my perspective with these systems is their insistence on giving the low contrast exposure first - better to set the shadow/ mid values, then bring in highlights - at least that's what I've found.

Click to expand...

I agree, perhaps not always, but usually a complex print is easier solved if first nailing grade/exposure for the mids.

If the Analyzer can give you a log d range, you could use a table like this to find the ratio of Green to Blue exposure to satisfy the negative's log d range. In my case, green filter gave 0.45 log d whereas yellow filter along gave 1.90 log d. The intermediate values are shown.
The colors of the lines are only for visual separation to read the graph easier.

Another way to answer your question to provide 'more control' is to just burn highlights with white light. This concept simplifies contrast control. It works because the blue light in the white does not do much at all to a highlight. So there is not need to remove the blue with any filtration or additional calculations beyond burn time.