RH Analyser Pro calibration question

[markbau]

Just started my first full calibration using under the lens Ilford filters.

Exposure corrections, grade 00 to grade 3 were fine, for grade 4 and 5 the instruction book is a bit confusing, it says "If you are using a colour or VC enlarger, you will usually need to correct the exposure at grade 4 and 5. (I'm fully aware that 4&5 filters need double the exposure that lower contrast filters do) The next sentence says "This increase is built into the meter's basic calibration" and then it says "before you make the grade 4 test strip reduce the exposure setting by a full stop" so I reduced it by a full stop and did a test strip which seems too light, 4 steps are paper white, 3 steps have some tonality. I then went back to the original exposure and did a test strip which had 7 distinct tonal steps. The instructions seem confusing, am I supposed to change exposure or not? Note, both test strips have a step that matches the D-0.04 patch.
BELOW: Grade 4 test strips
LH strip exposed the same as grades 00-4, RH exposure reduced by 1 full stop.

 

[markbau]

Just bumping this post, I'm a bit surprised there aren't a few RH Analyser users here. (maybe none of them calibrates) I did find an old thread from earlier this year asking the same question but it was never resolved regarding the exposure for the grade 4 and 5 test.

 

[dkonigs]

I've done the full exposure calibration routine on mine (for MGIV and MG V RC paper) also using the Ilford filters. I think all the numbers you get during this process end up relative to the default calibration of the device, assuming you used an unadjusted paper channel when running through the routine. That being said, I don't recall making any unique grade-specific adjustments to my process.

I think what the instructions are trying to say, is that the exposure adjustments needed for the Ilford filters are already assumed by the device's default calibration. So if you're not using the Ilford filters, then you need to compensate by undoing that adjustment.

Here is a gallery showing my selection of test strips and results from doing all of this:
https://imgur.com/gallery/w5ixkS1

I didn't bother doing the contrast calibration, instead simply trusting the datasheets for the paper. That's because I had already spent enough time doing the exposure calibration, and the contrast calibration process seemed even more confusing. However, someday I really should do calibration for my color head's dichroic filters as well. That's because I'm fairly sure they impact exposure differently from the Ilford filters, and the Ilford filters are too small for the lens I use when printing 4x5" negatives. (However, I have yet to really need anything above grade 3 for my negatives, and the larger differences are likely to be at grade 4 or 5.)

 

[markbau]

Thanks for the reply. I decided to start by testing MG RC IV thinking that if I didn’t need to make any adjustments I must be doing the tests properly, I could them move on to testing papers for which there are no numbers. So far I haven’t had to make any exposure adjustments from what was programmed into the unit.

I think your explanation is correct, using a color head you would need to make the adjustment but using below lens Ilford filters it would make sense that they would program the density difference into the program.

Thanks again for your reply

 

[dkonigs]

Thanks for the reply. I decided to start by testing MG RC IV thinking that if I didn’t need to make any adjustments I must be doing the tests properly, I could them move on to testing papers for which there are no numbers. So far I haven’t had to make any exposure adjustments from what was programmed into the unit.

I started with MGIV for exactly the same reason. The adjustments I did make were relatively minor, and are likely due to either me being nitpicky with a densitometer or not 100% perfect in my developing process. If I was eyeballing it versus the sample, chances are that my corrections would have been less/different. I was probably more consistent in my process with the MG V paper, but that paper does respond differently (especially at the higher grades).

 

[samcomet]

I would chime in on what dkonigs said. I too have used the MGIV but as FB papers and Ilford filters above the neg holder. I spent day(s) doing the testing only to find that the test result parameters were all nearly the same as the default ones with the RH Analyser. My view is that if I ever bought a bought a colour head I would have to re-do all that but right now I can see no reason to bother. The only minor adjustments I make are after eyeballing individual final prints, but I stress that in my workflow the RH gets me to, say 99%, of where I need to be. I should also say that presently using Fomabrom Varient III FB papers and Fomatol LQN dev, my results are more or less the same as using the Ilford product range with the default settings. I know that this does not answer your original question very well but it may help you formulate an approach to your workflow. Cheers, Sam

 

[adelorenzo]

I use one of these but I use dichroic filters so I can't offer much advice for you using Ilford filters. I did have to do some exposure correction for G4 and G5 for Ilford MG Classic. I never bothered calibrating the MGIV channel I only use it for contacts and proofs and it seems to work fine.

 

[markbau]

What I love about the analyser is that I get a print using its recommendation that I would take at least two or three test prints to get to. The other amazing thing is that it often gives me contrast recommendations that I wouldn’t normally consider. I can honestly say it is the best piece of photographic equipment I have purchased in a long time. Next task will be calibrating to Bergger paper.

 

[NortheastPhotographic]

I am going through the calibration of my Analyser Pro. When doing the contrast offsets using the step wedge, does the exposure really matter? I'm finding I have to increase exposure by 2-4 stops to get a maximum black in my print. Or if anyone has calibration figures for multigrade classic glossy using a VCCE LPL head that would save me a bunch of time...

 

[adelorenzo]

You just need to get your exposure so that you have a full range of tones on the step wedge, there should be one or more steps of pure black/white on either end. Otherwise it doesn't matter.

Start with the contrast values supplied by Ilford for the paper and fine tune from there. If you haven't done your exposure calibration yet you can use the paper's published ISO speed to input your initial numbers, the calibration manual explains how to do this.