Ilford Multigrade 500 & stained negs

Ilford Multigrade 500 & stained negs
I've used the Ilford Multigrade 500 head with negs developed in standard developers but was wondering how it would work with stained negs. Since the stain has an effect on the contrast would the probe read the contrast range correctly?

You say that the stain "has an effect on the contrast," have you measured this, how do you know? If you already know then you just need to run a test series with the enlarger again to calibrate for it (or create a compensation table to control future prints).

If you don't know then this question can't be answered beyond "the stain might cause a tiny little light loss which the probe will compensate for anyways."

Have you actually tried printing one of these stained negatives?

It certainly works. I use the dedicated RH Designs Analyser Pro F stop controller for printing Pyrocat negs. You may find that you need, as I have, to make a few more test strips but all up you will achieve a good result. I'm unable to add any stats and settings, not a boffin.

You have to distinguish between the contrast of the negative and the contrast of the paper provided by the head.

The contrats of the negative will be read correctly by the probe, as it basically captures the difference in density between the extreme zones of the negative; hence it works with all type of developers.

Now the stain of the negative can modify - like a filter- the spectrum of the light that will reach the paper: hence this might give your print a different contrast that was supposed to be reached with a determined setting on your head.

To summarize, the probe would determine the paper contrast needed to print your negative, but you would need
to adjust the settings of your head to get the right contrast to match the negative.

I have abandoned - at least for the moment - the staining developer (Prescysol ef) because it changes the characteristics of the paper contrast and I didn't have patience to find out how to compensate when using the RH Zonemaster (equivalent to Multigrade 500 head). Furthermore, the developer I'm now using (Xtol) gives the result I want so no urge to change.
Peter

I was thinking about how to compensate if I were to use this kind of developper.

I think I would make - not that easy - a negative of uniform density developped with such a soup, place it into the negative holder, and then proceed to the classical calibration process by contacting a stouffer wedge at the different settings of the head and tracing the curves with a densitometer.

That being said, I'm not sure the impact of such a filter on the filtration would not be density related, which would make this exercise not that helpfully accurate..

Maybe the best thing is to adjust the settings by visual inspection and experience.. after all, the MG 500 settings were designed for the defunct MG II paper whoses chromatic sensitization was different from the current Ilford productions we use today..

The best staining developers change the response of the film on a proportional basis, so a negative of uniform density probably won't help with calibration.

And the stain affects prints in a number of ways, including an affect on the UV transmission of the negatives.

So I am afraid a whole new round of calibration may be necessary.

MattKing said:

The best staining developers change the response of the film on a proportional basis, so a negative of uniform density probably won't help with calibration.

And the stain affects prints in a number of ways, including an affect on the UV transmission of the negatives.

So I am afraid a whole new round of calibration may be necessary.

Click to expand...

The purpose of the same density neg would be to simulate the filtering produced by the staining on the film emulion. As this stain would modify the color (i.e. the mix of blue/green spectrum) of the light hitting the paper it will hence give the print a resulting contrast than would differ from the one we get with traditional film developpers that leave films with a neutral base.

So the idea would be to proceed to a classical paper calibration, except we add this home made filter between the light and the print to get an idea of the impact of such change in the color onto the final contrast.

Re. the impact of the pyro on the respons of the film, this is something that would be dealt at the film calibration level, and of course would require a complete set test to get the right gradients and speeds for given SBRs..