PMK+ but no stain

[Tor-Einar Jarnbjo]

For no other purpose than to try something new, I have been trying to develop several films recently with the PMK+ developer.

I bought liquid concentrates from Bergger and have tried to follow their instructions as good as it goes:

• I mix the chemicals immediately before use with distilled water (1+2+100). The Bergger chemicals is the PMK formula and to get from there to PMK+, I add a pinch of Amidol.
• I then develop as usual at 20° for some time with one agitation every 30 seconds. I saw right now that Bergger recommends to agitate every 15 seconds, but I doubt that it is relevant for my problem.
• I use plain water as stop bath, changing water several times.
• I then fix in Rollei RXN, a non-hardening neutral fixer.
• I rinse in running water for at least 20 minutes with a final bath in distilled water. My tap water is so hard, that I otherwise get spots on my negatives. I don't use any photo flo or other wetting agents.

The develper works, at least kind of. I get negatives, which look great density-wise, but I can see absolutely no stain. I have also tried to scan several of the negatives as a colour slide, but the images are as neutral grey as can be, without any visible colour. I have read that not all films stain very well, but I have now gone through Adox Silvermax, Foma 100 and 400, Acros, FP4+, HP5+, TriX 400 and Rollei Ortho25, Retro80S, RPX100 and RPX400 and same thing throughout: no stain.

I have been using the Amidol myself as a paper developer without issues and it has already been used succesfully by an acquaintance for exactly this purpose (upgrading PMK to PMK+), so I would assume that the Amidol is good and not the reason for the missing stain.

Has anyone of you an idea or suggestion what I might be doing wrong?

 

[Sirius Glass]

For staining, I believe that after fixing, the film needs to be reimmersed in the developer for two minutes.

 

[Tor-Einar Jarnbjo]

For staining, I believe that after fixing, the film needs to be reimmersed in the developer for two minutes.

Why? Gordon Hutchings, who invented the PMK developer, says it is not.

 

[MattKing]

For staining, I believe that after fixing, the film needs to be reimmersed in the developer for two minutes.

Why? Gordon Hutchings, who invented the PMK developer, says it is not.

Originally Mr. Hutchings did make that recommendation, in the belief that it would increase the usable benefit from the stain.
Subsequently though, it was realized that the re-immersion in developer merely added over-all stain rather than stain that was proportional to the image and was therefore of no real benefit. Mr. Hutchings changed his recommendation accordingly.

 

[Lachlan Young]

1: have you tried an acid stop bath?
2: have you tried the developer as PMK without the Amidol?
3: what is the alkalinity of your tap water?

 

[Alan Johnson]

There should be some tanning. If you carefully examine the image on the emulsion side by reflected light it ought to be possible to see a relief image where tanned parts are slightly raised from the emulsion surface.

 

[Tor-Einar Jarnbjo]

1: have you tried an acid stop bath?
2: have you tried the developer as PMK without the Amidol?
3: what is the alkalinity of your tap water?

1: No. The Bergger instructions says that I can use a weak acidic stop bath if it is necessary to precisely time the developer. Otherwise rinsing in water is also good.
2: No AFAIK, the Amidol will only make a tiny bit better use of the film speed, but should have no impact on staining.
3: I have no pH-meter, but the last water analysis from my utility company says that the pH is between 7.35 and 7.75.

 

[Tor-Einar Jarnbjo]

There should be some tanning. If you carefully examine the image on the emulsion side by reflected light it ought to be possible to see a relief image where tanned parts are slightly raised from the emulsion surface.

In the correct light and perhaps with a lot of imagination, I think I can see a slight relief on the emulsion side. I can however see the same relief on negatives developed in regular chemistry and not in PMK. If you with 'tanning' only refer to the hardening of the gelatine and not the staining (as in colour cast), I can't rule out that there has been no tanning (still as in hardening of the gelative), but there is clearly no staining (as in colour cast).

Here is a crop of a FP4+ negative scanned as a colour slide. If I have understood the concept of a pyro developer correctly, I would expect to see a yellow/green/brown stain, which is denser around the exposed (darker) areas, but there simply is absolutely nothing there:

 

[Alan Johnson]

The faint color of the stain that you show is much the same as what I get with Delta 100 in Pyrocat HD.
Tanning is only seen when looking at a sharp edge on the emulsion by the reflection of a small light source, eg ceiling light.
It cannot easily be seen by reflected diffuse light, eg light from the sky.
I believe it is the tanning that provides the increased acutance with pyro developers.
The color of the stain varies, I have never seen a detailed explanation of why. It may be related to the grain size but AFAIK it does not affect acutance.

 

[Tor-Einar Jarnbjo]

The faint color of the stain that you show is much the same as what I get with Delta 100 in Pyrocat HD.

I don't know which colour you are referring to here. Do you see anything I can't see or measure? If you are talking about the scan I posted, it does not contain any colour information consistent with what the staining effect of a pyro developer is supposed to do. If I remove the luminance and amplify the chrominance as much as I can, there are some colour patches on the image, but it seems as if very bright and very dark tones have a blue colour cast, while midtones have a red colour cast. That can be explained by deviations in the scanner's sensitivity curves for RGB light, but not by a pyro inflicted staining of the denser areas.

Tanning is only seen when looking at a sharp edge on the emulsion by the reflection of a small light source, eg ceiling light.
It cannot easily be seen by reflected diffuse light, eg light from the sky.

I realize that I can only see the relief under specific lightning. If I hold the negative flat in front of me, slightly below the eyes and with the emulsion side up and shine onto the emulsion side with a light source pointing towards me from a shallow angle above the film strip, I think I can recognize a relief in the emulsion. But as I said, I can see the same effect with other negatives as well, which are developed in regular chemistry.

 

[Rick A]

I've been using PMK for years, the stain is not as prominent as you may think, in fact it is very subtle. The benefits of the stain show in printing, a slightly this looking negative will print with minimal difficulty. A well exposed negative will all but print itself. The tanning effect is just insurance that the emulsion is more scratch resistant which benefits soft emulsions prone to scratching. Reimmersion in spent developer only increases overall stain which could be good, or of no consequence, and really is not needed. I don't see the point of adding Amidol, PMK develops well enough on its own. Two 30 second water rinses in place of acid stop is all that's needed, alkaline or neutral fix is recommended. Washing film using the Ilford method is all that's needed, I also use a one minute soak in distilled water with two drops LFN per liter as a final rinse.

 

[Sirius Glass]

Originally Mr. Hutchings did make that recommendation, in the belief that it would increase the usable benefit from the stain.
Subsequently though, it was realized that the re-immersion in developer merely added over-all stain rather than stain that was proportional to the image and was therefore of no real benefit. Mr. Hutchings changed his recommendation accordingly.

This is like the big endians versus the little endians. It takes on the airs of a religious argument. Many also say that the the staining is proportional.

 

[Tor-Einar Jarnbjo]

I've been using PMK for years, the stain is not as prominent as you may think, in fact it is very subtle.

I have never seen a PMK-developed negative, so I didn't expect anything particular. The stain may very well be subtle. If it is, as often claimed, supposed to work as a contrast filter when printing on multigrade paper, it must however at least be visible or measurable and in my case, there is no stain to be seen at all, neither by the naked eye, nor by the scanner. When printing with a multigrade head, the yellow colour cast is clearly visible before it has much noticeable effect on the print contrast.

If I look at how other present their pyro developed negatives, here e.g. a comparison between FP4+ in ID11 and PMK, there is a pretty obvious colour cast in the PMK negatives. If I hold my own FP4+ negatives next to eachother, some developed in ID11 and the most recent ones in PMK, there is absolutely no visible difference in colour tone between the negatives.

 

[Tor-Einar Jarnbjo]

This is like the big endians versus the little endians. It takes on the airs of a religious argument. Many also say that the the staining is proportional.

The point of the stain is for it to be proportional and denser in the denser areas of the negative. Therefore, the afterbath in used developer is now considered pointless, since it only increases the stain uniformly over the entire negative. The proportional stain is supposed to be formed during regular development and is not related to the afterbath, which Hutchings recommended in the earlier editions of his work.

If I for whatever reason wanted a uniform colour cast to the entire negative, I can just as well drop in a colour filter in the enlarger when printing. I don't have to play with chemical magic to achieve that.

 

[Rick A]

The point of the stain is for it to be proportional and denser in the denser areas of the negative. Therefore, the afterbath in used developer is now considered pointless, since it only increases the stain uniformly over the entire negative. The proportional stain is supposed to be formed during regular development and is not related to the afterbath, which Hutchings recommended in the earlier editions of his work.

If I for whatever reason wanted a uniform colour cast to the entire negative, I can just as well drop in a colour filter in the enlarger when printing. I don't have to play with chemical magic to achieve that.

This last statement makes no sense. You still need contrast filters when printing on multi grade papers with any negative, staining negatives are no different, it's not a magic bullet.

 

[pentaxuser]

OP, you seem to have covered all the points that have been raised about why you have no stain, which as I understand things should be a yellowish-green colour. The one thing which is not clear to me is whether any of the responders that have so far responded are using Bergger PMK.

You may need responses from users of the Bergger solution. Can you take a digital photo of one of your non PMK negatives and another of your PMK negatives. Ideally both of the same kind of film so PMK users can say if their negatives look similar

pentaxuser

 

[Tor-Einar Jarnbjo]

This last statement makes no sense. You still need contrast filters when printing on multi grade papers with any negative, staining negatives are no different, it's not a magic bullet.

Please read what I respond to and it makes sense. Sirius asked if it is not necessary to bathe the negatives in the used developer after fixing. It is not, because it only increases overall stain and is not related to the proportional stain, which is wanted with pyro developer. So, I tried to explain why a uniform stain is pointless, since if I for some reason wanted that (I didn't say that I do) I could just as well use a colour filter when printing instead.

I would much more appreciate if you would follow up on my response to your post. I have already posted scans of my negative. Where is the subtle stain you are referring to?

 

[Tor-Einar Jarnbjo]

OP, you seem to have covered all the points that have been raised about why you have no stain, which as I understand things should be a yellowish-green colour. The one thing which is not clear to me is whether any of the responders that have so far responded are using Bergger PMK.

Bergger says that it is the original Hutchings recipe. It should be the same as any other PMK developer.

You may need responses from users of the Bergger solution. Can you take a digital photo of one of your non PMK negatives and another of your PMK negatives. Ideally both of the same kind of film so PMK users can say if their negatives look similar

I tried to take a picture of the negatives side by side, but I don't have any macro lens and honestly, you don't see much. Please believe me that I am sitting here with FP4+ negatives developed in both PMK and other developers (mostly Rodinal or ID11) and there is no difference in the colour tone of the negatives.I already posted a positive scan of the negative. If it has any subtle colour cast at all, there is a very meak bluish tint in the shadows and the highlights and a reddish tint in the mid-tones. As I wrote, I am however more likely to believe that red/blue tint is lack of linearity in my scanner hardware and not actually present on the negative.

 

[pentaxuser]

I understand your frustration,Tor-Einar Jarnbjo. I was simply wondering if there were other users of the Bergger chemical and trying to eliminate other possibilities. It is true that Bergger says it is based on the Gordon Hutchins original solution and nowhere does it seem to say that with certain films you will see no stain at all. If there are other circumstances in which Bergger PMK produces no stain you'd expect it to warn the user what those circumstances might be and it doesn't.

Unfortunately if you are convinced you are doing everything required and that there is nothing wrong with the Bergger chemical then the conclusion would seem to be that in your case the stuff doesn't work as you had expected it to.

My sympathies.

pentaxuser

 

[Alan Johnson]

https://www.photo.net/discuss/threads/pmk-pyro-amidol.22195/
Here Ed B says that the addition of amidol changes the color of the negatives somewhat.
Any chance you added an incorrect amount?

 

[Tor-Einar Jarnbjo]

https://www.photo.net/discuss/threads/pmk-pyro-amidol.22195/
Here Ed B says that the addition of amidol changes the color of the negatives somewhat.
Any chance you added an incorrect amount?

When I started yesterday, I discovered that the batteries in my chemical scale were drained, so I must admit that I simply eye-balled the amount of Amidol. It might actually have been a bit more than usually recommended. With paper developers, I have experienced that you need a certain amount of Amidol for the developer to 'kick in' and increasing the amount does not have much effect on how the developer behaves. I might for the same reason subconsciously have added more Amidol than really needed to the PMK developer yesterday.

I'll give it another go tomorrow without Amidol and see what results I get if I use the PMK developer pure.

 

[MattKing]

Amidol is acidic, and may affect the pH of the resulting working solution..
Does changing the pH affect how much visible stain is there? I don't know.

 

[Tor-Einar Jarnbjo]

Amidol is acidic, and may affect the pH of the resulting working solution..
Does changing the pH affect how much visible stain is there? I don't know.

That is a good point. There are lots of conflicting information to be found about pyro, pH and the effect on staining. It is often claimed that using acidic fixers after a pyro development will reduce or even remove the stain and it is therefore recommended to use neutral or alkaline fixers. Bergger writes something different in their instructions for the PMK developer. They say it is only important to use a non-hardening fixer, but they do not require the fixer to be non-acidic. The instructions also allow for the use of an acidic stop bath.

As I wrote earlier, I used only a plain water rinse as stop bath and a neutral fixer. If the pH should be relevant for staining and Amidol is acidic, the explanation may of course be that too much Amidol reduced the pH enough to prevent staining.

 

[Tor-Einar Jarnbjo]

Amidol is acidic, and may affect the pH of the resulting working solution..
Does changing the pH affect how much visible stain is there? I don't know.

I tried to develop another strip of FP4+ today without adding amidol to the Bergger PMK developer. I now have a very obvious green and yellow stain to the negative, just as it is supposed to be. I will do another attempt with properly weighed amidol, but it seems that adding too much amidol to the PMK developer prevents the stain from emerging.

When scanning the negative as a color slide film (white balance is set to the film base between exposures), there is already a very clear colour cast to the scan:

Removing the luminance and just keeping the chrominance of the image also reveals that the density of the stain, at least to a certain degree, correlates with the density of the silver image:

With amidol, I developed for 12 minutes at 20°. Since those negatives were already quite thin and amidol is supposed to increase the potency of the developer, I increased the time to 15 minutes and temperature to 22° for the new attempt without amidol. That increased the contrast quite a bit, but I still lack some details in the shadows. The grain is quite a bit finer without amidol, but the negatives developed with amidol appear to be a bit sharper.

For those who are interested, here the full image and a properly inverted crop of the logo above:

 

[MattKing]

Glad my guess seems to have helped.