Pyrocat HD thin negatives?

[instantcrow]

This is my first time with pyrocat HD. I've shot some test exposures for film speed on Fomapan 100 using a white mat board set to zone 10 with Stouffer wedge. The Pyrocat HD I mixed in glycol using Sandy King instructions (I spent 4 years in a chem lab, so confident I followed standard procedures). Developed the film using 300ml working solution (3ml part A: 3ml part B: 294ml distilled h20) at 20degC in a Stearman daylight tank. I ran several different times 12, 16, and 20 minutes, and the negatives were all thin. I developed an old sheet of fully exposed HP5, and it, too, was thin. at least to my eye. I've attached some photos. My goal is platinum contact printing, so I'm shooting for higher density negatives.

LIkely culprits to my mind: most likely bad Solution A. I mixed a 100ml batch using the 0.2 g phenidone, and I think I failed to get the remnant powder out of the bag. thanks for any ideas.

 

[koraks]

Welcome to Photrio!

I mixed a 100ml batch using the 0.2 g phenidone, and I think I failed to get the remnant powder out of the bag.

A significant error in the amount of phenidone will most definitely affect developer activity. However, it would have to be a rather significant error indeed. You mention a bag supposedly containing just 0.2g (200mg) of phenidone. I can see how just powder sticking to the bag might be a significant factor. Did you weigh the ingredients?

Also, the mention of a small bag supposedly containing a pre-measured amount of phenidone suggests you're using some kind of ready-to-go kit for the pyrocat. Is this correct? If so, which kit did you use? And also, how did the various ingredients and esp. the phenidone and the pyrocatechol look?

I agree both sheets in the photo look rather thin and they also appear to have a high stain-to-silver ratio. This would be consistent with a problem with the phenidone; i.e. either there was not enough of it in the mix, or it was in bad condition.

 

[instantcrow]

thanks. It was the 10L working solution kit from photographers' formulary. So it included enough to make 100ml of each solution. The powders were white, and part A is clear perhaps a slight straw color. I'm certain it has very scant developing power as even at 20 minutes of developing time I see no further building of the highlights.

 

[koraks]

I'd get in touch with Formulary. I've only ever mixed ourocat from bulk chemistry and it has always worked fine, but as said, it sounds like there's a lack of phenidone in
your developer. You didn't weigh the ingredients before mixing, I assume?

 

[instantcrow]

The phenidone was listed as 200mg, and the bag it was in probably weighed double that so it was difficult to transfer and weigh such a small amount. I recall that it was difficult to empty all of the phenidone from the plastic bag.

I'm mixing up another batch this time 1L, so hopefully it will work out.

I rechecked my solution A, and there is a scant very slight white precipitate. But I think that is mostly likely bromide and/or bisulfite. Neither of these would impact developing power.

thanks for ideas!

 

[Andrew O'Neill]

I often use a minimum of 5ml of each stock. 3ml is probably okay, but seems too minimal. In fact, I often prefer (especially with HP5) a 1+1+50 dilution.
Save yourself film...and money... and cut it up if you are just going to contact print a Stouffer step wedge. I often do such tests on 4x5 film, then made adjustments if required... which is minimal.
You might want to consider sourcing chemicals for make up the developer, rather than relying on kits. Cheaper.

 

[John Wiegerink]

Making Pyrocat developers from scratch is not that hard to do. You still have to treat some of the chemicals we use for making developers with respect, but you do with some household cleaners and disinfectants also. I won't buy certain developers "ready made" from places like Freestyle or Photographers Formulary, that contain ingredients like Glycin since the mixed potion has a shelf life that's not very long. Who knows how long it sits on the shelf before it's sold. It could be expired (dead) when you get it and you won't know until it's toooooo late. Not cutting down Photographers Formulary at all, in fact that's where many of my chemicals come from for making up my developers. It's the only place I can get my Glycin from, but when I buy it I know it's freshly made.

 

[Scott J.]

Have you actually measured the densities of the individual steps? I've done a lot of these types of step wedge tests using pretty much the same setup as you (4x5 step wedge, Pyrocat developers, photographing a large piece of white foam board, metering for +5 stops above Zone V, etc.) and your densities are, just based on visual inspection, likely higher than what one aims for when doing Zone System tests for conventional darkroom printing and/or scanning. You mention wanting to do Pt/Pd printing, so you probably do need slightly more density, but I don't think that what you have here is really all that far off. Your Zone I density (Step 19), for example, is well above B+F (I'm guessing~0.20 above B+F using the Blue channel), and your Zone VIII (Step 5) looks pretty thick, as well. All in all, these look too well developed to imply a problem with your developer. My guess is you just need a little more exposure and/or development intensity (time, temp, agitation) to reach your target density range for Pt/Pd.

Did you pre-wash the film, and what did your agitation routine look like?

 

[instantcrow]

I washed the film in distilled water for 4 minutes prior to developing. I agitated for first 30s then 10s/minute thereafter.

I don't have a densitometer, and admittedly difficult to capture with an iphone. All I can say is that fully daylight exposed film is quite transparent rather than black/opaque. I'm confident my film speed test shots were metered correctly. These test shots have super light density in the highlights to my eye. I'll try some small test prints and see what they look like in terms of dynamic range. thanks

 

[Scott J.]

I washed the film in distilled water for 4 minutes prior to developing. I agitated for first 30s then 10s/minute thereafter.

I usually agitate for the first full minute in Pyrocat-MC (basically the same developer activity as the HD variant), so you might try that. That should add some noticeable density and also help to alleviate any streaking in continuous-tone areas (e.g., skies). Otherwise, you have a solid approach.

Regarding the general "character" of negatives developed in staining developers, since one is typically aiming for target densities specifically measured via the blue channel (as opposed to the combined R-G-B "visual" channel), the high-density areas do tend to appear thinner to the naked eye than those produced by a non-staining developer. For example, a Zone VIII blue-channel density in a Pyrocat-developed negative might measure 1.3 units above B+F, but on the visual channel it may only be 1.0 (because red and green light still pass somewhat easily through the brown stain). Your eye will detect this same apparent difference in visual density between the two types of negatives, which can be confusing at first. Doing a print test is the ultimate way to know how to adjust exposure and/or development, so you're basically 90% of the way there.

 

[koraks]

These sheets do not show signs of a simple mistake in the development process. Something's wrong with the developer.

 

[John Wiegerink]

These sheets do not show signs of a simple mistake in the development process. Something's wrong with the developer.

I agree 100%! If it's a bad kit from PF I'm sure we'll hear from a few other folks having the same problem.

 

[Alan9940]

Personally, over the years I've had several instances of thin negatives with Pyrocat-HD. When I first started using this developer, I bought the pre-mixed glycol kit from PF, but I found the quality to be sketchy. So, I started mixing it myself. I've mixed it in both distilled water and glycol, but never see the storage longevity that I've heard about from others. Nowadays, I mix up a batch in distilled water and toss it after six months; no more issues.

 

[instantcrow]

Lots of good input here. I'm beginning to wonder if the glycol trick is worth it assuming you use the chemistry rapidly. Even with the glycol version you'll be suspect at some point whether it's 6 months or 1, 2 or 3 years...

 

[koraks]

Personally I prefer glycol mostly because of the peace-of-mind factor it affords. However, I generally mix small batches of the developer, so it never sits for longer than about a year or so. I've never had it go bad. I know others have had problems; some of those ultimately traced to plausible causes, while some remain unresolved mysteries.

 

[david schaller]

I mix up Pyrocat HD with distilled water, 500ml of A and B at a time. I’ve never had any problems for over a year per batch.

 

[Andrew O'Neill]

I've never had an issue with glycol mixed PCAT-HDC. As others have pointed out, bad chemistry.

 

[retina_restoration]

thanks. It was the 10L working solution kit from photographers' formulary. So it included enough to make 100ml of each solution. The powders were white, and part A is clear perhaps a slight straw color. I'm certain it has very scant developing power as even at 20 minutes of developing time I see no further building of the highlights.

I've had bad/expired chemistry from Photographers Formulary before. I am of the opinion that you were working from old, defunct chemistry. This is clearly a bad chemistry issue, IMO.