More Analyser Pro Calibration Weirdness...Densitometer Edition

NortheastPhotographic · Jan 15, 2020

So as anyone with an Analyser Pro knows, the calibration kit includes a piece of paper with various patches. One is supposed to be paper white, another is supposed to be density 0.04, and another couple of very dark patches....

I just got my XRite 810 up and running and so of course I tried the 0.04 patch, which is supposed to be my reference for this part of the calibration. However the first time I started reading that patch I was getting 0.15 in Vis mode. I assumed my unit must be out of calibration so I went through the steps, got the calibration reference, etc. Still it reads 0.15, and I'm quite sure my calibration is correct...

Can anyone with the calibration kit for the Analyser and a densitometer read their patch and tell me what they're getting?

Unless Vis mode means something other than what I think it means, I'm not sure what's going on. The 810 is new to me so it's possible that I'm not understanding how to read the results.

As a sanity check, yes I'm in the reflection mode.

calebarchie · Jan 15, 2020

You calibrated it with transmission wedge, you need to calibrate it with reflection plaque also. Did you do this?

Honestly you are better off with a simpler densitometer for this stuff.

NortheastPhotographic · Jan 15, 2020

calebarchie said:
You calibrated it with transmission wedge, you need to calibrate it with reflection plaque also. Did you do this?

Honestly you are better off with a simpler densitometer for this stuff.

No, I calibrated it with the metal plaque. Actually I calibrated both modes prior to testing. I don't think there is anything wrong with the XRite 810. There aren't a lot of TR densitometers available unless you buy something really old or a really expensive Heiland.

removedacct3 · Jan 15, 2020

If I measure the white one labeled 'paper base' I get 0.07, the patch labeled '0.04' gives a 0.11 reading. So yes, the difference is 0.04. I'm using a Agfa-Gevaert D102 densitometer.

NortheastPhotographic · Jan 15, 2020

MrclSchprs said:
If I measure the white one labeled 'paper base' I get 0.07, the patch labeled '0.04' gives a 0.11 reading. So yes, the difference is 0.04. I'm using a Agfa-Gevaert D102 densitometer.

THE DIFFERENCE!!!!!!!!!!!!! Bah, of course that's it. My understand is that the patch itself should read 0.04.

So when I'm making my test strips should I be finding the difference from an unexposed and fixed paper base patch?

ic-racer · Jan 15, 2020

Frequently one can just eyeball the 0.04 step on your step-wedge contact test prints. It is just off white.

removedacct3 · Jan 15, 2020

NortheastPhotographic said:
... finding the difference from an unexposed and fixed paper base patch? ...

Yes, that is how I tend to do it. Changing the offset in reflection mode requires fiddling with adjust screws. The ease of use and the location of those screws tell me that you're not supposed to zero reflective readings for every paper you test.

NortheastPhotographic · Jan 15, 2020

MrclSchprs said:
Yes, that is how I tend to do it. Changing the offset in reflection mode requires fiddling with adjust screws. The ease of use and the location of those screws tell me that you're not supposed to zero reflective readings for every paper you test.

I don't think the XRite 810 has a 0'ing function. Mine is reading the white patch at .05 and the grey patch at .12 now. So the difference is about .07.... I suppose close enough...

NortheastPhotographic · Jan 15, 2020

I have another question which I'm not sure anyone has the answer to...

When calibrating for speed, the instructions state to take 1 reading, then make test strips throughout the filter levels. However, I'm using a VCCE head with my LPL. I wonder if I should meter each filter level since my head in theory is consistent from 0-3 (there is no 00). One thing I've noticed after my first calibration session is that all my strips are too dark even at the lightest patch.

Saganich · Jan 15, 2020

Yes zero on the paper white. So on my Macbeth TR524 when I zero on the paper white tile and then measure the 0.04 tile I get 0.04.

NortheastPhotographic · Jan 15, 2020

Yeah again I don't believe there is a way to 'zero' out the 810. You can calibrate it for the targets however... I wish I had another target I could read to confirm that I'm getting the correct results.

Edit: Actually it occured to me that I do have reference targets. They grey patches on my color checker passport represent .05 to 1.50. Each one of those is reading correctly.

I suspect my reference target is giving me the correct reading. Though the difference between the paper white target and the .04 target for me are .07

dkonigs · Jan 15, 2020

NortheastPhotographic said:
Yeah again I don't believe there is a way to 'zero' out the 810. You can calibrate it for the targets however... I wish I had another target I could read to confirm that I'm getting the correct results.

Technically, there is. Its called "do quick subtraction in your head" When doing this myself, I also measured the paper base somewhere around 0.07.
Of course since then I've gotten new calibration references, but I haven't re-checked the paper since.

markbau · Jan 16, 2020

My, new, Heiland measures it at exactly .04.

removedacct3 · Jan 16, 2020

NortheastPhotographic said:
When calibrating for speed, the instructions state to take 1 reading, then make test strips throughout the filter levels. However, I'm using a VCCE head with my LPL. I wonder if I should meter each filter level since my head in theory is consistent from 0-3 (there is no 00). One thing I've noticed after my first calibration session is that all my strips are too dark even at the lightest patch.

No. You meter once using unfiltered light. When exposing test strips make sure that the grade settings are the same on the enlarger and on your RH meter. For example, let's say you are about to print the grade 0 test strip. In order to do so you dial in the required filtration on your colour head AND you tell your RH device to use grade 0 as well. Based on your single measurement with unfiltered light, the analyser will give you the calculated time to use for that grade 0 strip. Doing so will give you different exposure times across the grades all based on a single, unfiltered light measurement.

Regarding patches that are too dark. In my case, that was fairly common as well. RH's calibration manual has a special section where it describes how to remedy that.

On a more theoretical note. The factory settings of your analyser are based on the Ilford 'under-the-lens' gelatin filters. Perhaps the VCCE head differs significantly from Ilford's industry standard. That could be very well the case and if so, that provides a sensible explanation of the differences.

Even with the use of a densitometer, the more papers I calibrated, the better I got at it.

NortheastPhotographic · Jan 17, 2020

I calibrated MG Classic Glossy last night in Ansco 130, 1:2, 2min dev time, aprx 70-75F in a Nova slot processor.

First I made strips and used my densitometer to find 0.04. These were visually close to paper base, and the resulting test print I attempted to make was wildly under exposed! So I decided to just match the grey patch visually and skip the densitometer. My current offsets are:

0 = 0 / 1 = -6 / 2 = -6 / 3 = -16 / 4 = -30 / 5 = -30 (I have no 00 in the VCCE head, and it has no below-the-lens filter holder).

This yielded prints that are much closer to the correct exposure, but of course I haven't made a print at every grade just yet. There is definitely a learning curve with the timer itself. Last nights calibrations were pretty frustrating and I was about ready to pitch the unit in favor of a stop clock, but I stuck with it. At the end of the night I was able to make a reasonably correct looking print from meter readings. I may just have to tweak the offsets as I go forward if I get any more bad exposures. For now, I'll be making test strips to conserve paper. But at some point I can see trusting the device more. Really, it's my offset's I don't yet trust.

removedacct3 · Jan 17, 2020

That pattern looks familiar to me ... for higher grade values the exposure value decreases with grade 4 and 5 being really low.

adelorenzo · Jan 17, 2020

Even with a calibrated paper I still make a test strip on most prints, usually at 1/6th of a stop just to fine tune the readings I'm getting from the device.

The best thing is that the analyzer lets you figure out the contrast range of the negative. I rarely have to change my initial contrast setting, maybe a half a grade or something.

mshchem · Jan 17, 2020

Someone gave me a fancy densitometer, I gave it back, and it got recycled. I'm using the metal standard as a shim for a cabinet. I'm not all that bright anymore. If only I would have had one in the good old days. Of course I'm not trying to run a commercial lab. Keep at it!

NortheastPhotographic · Jan 18, 2020

So now that I have a bit of a better understanding of the calibration process...I've been thinking what I might do to further refine my offsets is take what I have now, and then make 6 step test strips at each grade. I should then be able to really nail 'off white' or the 0.04 patch.

Then I can calibrate for the new RC MG V. Oy vey. God help me if I ever get tired of Ansco 130.

removedacct3 · Jan 19, 2020

I am using a Heiland cold LED light source and as a result all default values in my Zonemaster are way off. When I calibrate my Zonemaster for a new-to-me paper, I will do two calibration sessions. For the first one I use a default 4 step size for all grades. After I entered the values of the first session, I'll do a second one using different step sizes to fine tune my settings. For grade 00, 0 and 1 I use a step size of 4, for grade 2 and 3 I use 6 and for the 4 and 5 grade I use 12.

This procedure is also described in the Zonemaster calibration manual and is well worth the effort.

payral · Jan 19, 2020

MrclSchprs said:
I am using a Heiland cold LED light source and as a result all default values in my Zonemaster are way off. When I calibrate my Zonemaster for a new-to-me paper, I will do two calibration sessions. For the first one I use a default 4 step size for all grades. After I entered the values of the first session, I'll do a second one using different step sizes to fine tune my settings. For grade 00, 0 and 1 I use a step size of 4, for grade 2 and 3 I use 6 and for the 4 and 5 grade I use 12..

I am using a heiland VC Head too and I intend to calibrate my ZMII too for some FB papers. Which paper did you already test ? Any advice to share ?

removedacct3 · Jan 19, 2020

Philippe, see the attached PDF file. It should give you a starting point. If your ZMII paper channel still has the factory (Ilford) defaults, I would reduce 2 stops (24 units) for each grade before doing the first calibration session. Good luck!

payral · Jan 19, 2020

Thank you so much. I will try like that next week.

RalphLambrecht · Jan 19, 2020

NortheastPhotographic said:
No, I calibrated it with the metal plaque. Actually I calibrated both modes prior to testing. I don't think there is anything wrong with the XRite 810. There aren't a lot of TR densitometers available unless you buy something really old or a really expensive Heiland.

The Heiland is the best densitometer I've ever used and I used a few; still reads the same compared to 25 years ago; amazing consistency!

NortheastPhotographic · Jan 21, 2020

The pain continues... I went through some fine-tune calibrating tonight to see if I could perfect my offsets. I thought I did so but of course when I go to make a print it's totally off. I'm not sure if I'm just incorrectly judging the strips or if it's something else. I will say as I continued printing later into the evening the enlarger started flickering quite a bit. I think my bulb may be going out... I'm guessing a bad bulb can cause issues during calibration. Frankly I am not looking forward to starting over again.

I wonder if the analyser was the right choice over a stop clock... I wasn't a bad split grade printer at one point and now I feel like I'm dicking around and not getting anywhere.

More Analyser Pro Calibration Weirdness...Densitometer Edition

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