Pyrocat-HD from Photographers' Formulary

[LFGuy]

is there a speed difference in the rotation of a unicolor 8x10 film tube on a unicolor rotary base vs the jobo expert drums? If there's not, then I'll just go with Clay's suggested time for the FP-4. Does anyone have one for HP-5?

I've used Clay's times for FP4 on my Unicolor with good results. I don't have a densitometer tho.

 

[sanking]

Jeremy wrote:

"Is there a speed difference in the rotation of a unicolor 8x10 film tube on a unicolor rotary base vs the jobo expert drums? If there's not, then I'll just go with Clay's suggested time for the FP-4. Does anyone have one for HP-5?"

Clay and I have had some recent correspondence on this and I hope he comments further.

Basically, the Unicolor rotary base has just one speed, a fairly slow rpm, whereas the Jobo can be adjusted to very slow or fairly fast rotation. If you are using Job I recommend that the rpm be set to the slowest rotation the unit allows. If the rpm is set too high you may, and especially with high speed films like HP5+, get a fairly high b+f, or general stain. Slowing down the rpm reduces this possibility. It is less important with slow and medium speed films such as FP4+.

Sandy

 

[sanking]

Donald wrote:

"I substituted Sodium Carbonate for Potassium Carbonate since I already had it on hand for other uses. I spoke with Sandy King prior to doing this. The only change is I mix it in five times the amount of water for the stock solution. I then change the mix to 1-5-100. The reason is that Sodium Carbonate reaches solution saturation much more rapidly then Potassium Carbonate."

Yes, I want to reiterate what Donald writes. At the same weight of dry chemical sodium carbonte can be substituted for potassium carbonate with no difference in development charactericstics. A Pyrocat-HD working solution of 1:1:100 using the recommended formulat of 100g of potassium carbonate per 100ml of water gives same results as a working solution of 1:5:100 using a 20% solution of sodium carbonate.


Sandy

 

[clay]

Just got back in from printing some HP-5/Pyrocat negs in palladium!

Sandy and I have been corresponding on the Jobo issue, and I am now a total believer - the slower the better with pyrocat. It is not prone to streaking and uneven staining to begin with, so the the slow speed should not be a problem. What I was experiencing with higher speed films such as Tri-X and HP-5 was that the spent developer was almost muddy brown when I dumped it from the jobo, and the film rebate (edge) was stained a brownish/pinkish color. My printing times on some negatives was pretty long. Sandy suggested that too much aerial oxidation might be occuring due to my using the Jobo at the "F" setting, which is supposed to be the film setting. So I re-ran some tests for HP-5 at the 2:2:100 dilution and the absolute slowest speed setting, and voila - the problem disappeared.

I have the test data and will post some times if you tell me what process you are using so I can use the proper target density range for your ideal negative. Coincidentally, Sandy also now recommends a full-spectrum (all channel) target density range for palladium at 1.3. I now concur with that heartily. My best print from the latest batch had exactly that range: shadow values at .25, highlights at 1.55. This also happens to be the perfect Azo/Amidol grade 2 density range. So you can have your cake and eat it too!

Clay

 

[Jeremy]

Clay,

I'm shooting 4x5 and will be developing in pyrocat-HD using a unicolor tube on a uniroller for silver enlargement from a color head. I'm hoping to use times at 75 degress F as that is the most common temperature at my house. Glad to know about the speed settings as I'm planning to use your FP4 time for my initial testings at 75 F after I order my chemicals.

Also, I'll be in Houston/Galveston the weekend of August 8th. If you might have some free time to go shooting out on what you people who lack the ocean call a beach (that's my virginian talking out) please send me an email or PM. I'll be out on the island all day on Saturday and most of Sunday.

 

[clay]

Alright. My recent testing of HP-5 in the Jobo a the 2:2:100 dilution at 73 degrees and the slow rotation gives me the following times for a target DR of 1.05:

Normal (SBR 7) EI 250 - time 6 minutes
Normal +1 (SBR 6-) EI 250 time 10.5 minutes
Normal +1.5 (SBR ~ 5.5) EI 320 16 minutes

Notice that I don't have any N- times at this dilution. It is just too strong. My guess would be that an N-1 could be achieved at 4 minutes, but I didn't run any times this short. If you are only doing silver, I think I would use the 1:1:100 dilution, unless you are faced with a serious N+ expansion situation. Sandy might have some better information on the proper times for this dilution.

And about the Houston/Galveston area, sure. I have to check with the ruling authorities and so forth, but I would definitely like to get out early before the heat and humidity gets truly murderous. Email me off list and we'll see if we can work it out.

Clay

 

[sanking]

For silver printing I would also recommend the 1:1:100 dilution of Pyrocat-HD. Unfortunatlely I can't provide any data at this time about the combination. I am in the midst of a major renovation project on my computer room/library and my main computer is down and all files and books from the room are temporarily scattered in the three adjacent rooms.

Sandy

 

[Ed Sukach]

My guess would be that an N-1 could be achieved at 4 minutes, but I didn't run any times this short.

Without try to be contentious, I've been contemplating the idea that "*No* development should ever take less than five (5) minutes, because it will be uneven."

I've done a few hundred, or so, rolls of C41 color, where the usual color development time is three minutes and fifteen seconds ... and although I've certainly made my share of boneheaded mistakes, I cannot say that "uneven development" was ever a problem. Likewise, in reading "Worlds in a Small Room" by Irving Penn, I've noted that,

"Most of the photographs in this book were taken on Kodak Tri-X film. The only exposure records for which I have an accurate record, the pictures in New Guinea and Morocco, show that Tri-X was exposed at 160 ASA, or at 80 to 125 ASA for very dark skins. Development was usually in UFG, 3 to 5 minutes at 68 degrees F."

- Irving Penn, "Worlds In a Small Room", Notes, page 92.

So, being of a questioning nature - I'm wondering about the the reasoning behind the "No less than five minute rule", propagated by Kodak, Ilford, Agfa ... and just about everyone else - and so readily *broken* by Irving Penn.

I *may* just choose to ignore this rule altogether in the future.

Comments?

 

[clay]

I don't think there is any real technical reason that 'shorter than 5 minute development times' will not work, but it seems more a practical one of how consistent you can be at timing and stopping development. A 20 second variation at 6 minutes is a 5.5% variation. The same timing error for a 3 minute time would be 11%. If you are tray developing and using and acid stop, I imagine your potential timing error would be small.

As an aside, there was a thread on the Bostick and Sullivan alt-photo list a few months ago about using amidol as a developer for platinum negatives (Terry King says this is what Frederick Evans used). His times for FP-4 were about 2 minutes if I remember correctly! So if you're in a hurry, there you go!

Clay