Pyrocat with BTZS Tubes - Dilution Question

Baisao · Feb 23, 2016

I need some assistance and I am hoping Sandy King might chime in. I am trying to use Pyrocat-HD (1:1:100) @ 21° in BTZS tubes to develop FP4+. I am having tests done by The View Camera Store and the initial test for dilution is to develop for 4 minutes.

The problem is that the step wedge is too thin at 4 minutes using the above parameters. I barely have any density at step 11.

If I am getting an exceptionally thin neg at 4 minutes, does it point to an error on my part or a characteristic of Pyrocat-HD?
What is the best dilution and/or temp to use Pyrocat-HD with FP4+ in BTZS tubes?

Thank you,

Jim

Rick A · Feb 23, 2016

http://www.pyrocat-hd.com/
http://btzs.org/

Baisao · Feb 23, 2016

Rick A said:
http://www.pyrocat-hd.com/
http://btzs.org/

I'm familiar with the documentation on both sites and this is why I am hoping someone with direct knowledge will speak up. I know the method that Sandy King recommends on his Pyrocat-HD site so I am confident that the developer works at the dilution I am using in BTZS tubes. Also, I have been sending my test step wedge to Fred Newman of the View Camera Store (BTZS) to gauge dilution but it is not working as Fred expects that it should.

MattKing · Feb 23, 2016

I don't think Sandy King comes here any more.

Baisao · Feb 23, 2016

MattKing said:
I don't think Sandy King comes here any more.

Thanks for letting me know, Matt.

juan · Feb 23, 2016

I'm not exactly sure what you are doing. Are you doing the BTZS tests with VCS reading the negatives? If so, you should be doing multiple negatives at different development times to determine proper times for you. I don't understand the reference to one development time, as multiple times are needed to create a scale.

The 1:1:100 dilution works for many people.
Juan

Baisao · Feb 23, 2016

juan said:
I'm not exactly sure what you are doing. Are you doing the BTZS tests with VCS reading the negatives? If so, you should be doing multiple negatives at different development times to determine proper times for you. I don't understand the reference to one development time, as multiple times are needed to create a scale.

The 1:1:100 dilution works for many people.
Juan

This is a pre-test of sorts that VCS uses to determine the correct dilution. Once determined, the multiple negatives are developed just as you say.

One thing to note is that Sandy calls for 75ml per 4x5 sheet. I was using 60ml. Could that missing 15ml really cause such really thin negs?

ritternathan · Feb 23, 2016

Baisao said:
This is a pre-test of sorts that VCS uses to determine the correct dilution. Once determined, the multiple negatives are developed just as you say.

One thing to note is that Sandy calls for 75ml per 4x5 sheet. I was using 60ml. Could that missing 15ml really cause such really thin negs?

Pyrocat is already a very diluted developer so start with the recommended 75ml. Also look at the website pyrocat-hd.com and suggested development times (which recommend starting with 8:30 for FP4+ EI 125 at 21C) and adjust your time depending on your printing process. Also, if you go over to Large Format Forum, I think Sandy still visits there. Good luck.

MVNelson · Feb 24, 2016

I have done BTZS film test with pyrocat-mc in BTZS tubes with okay results at 1:1:100 but much better result with 1.5:1.5:100 .

Baisao · Feb 24, 2016

ritternathan said:
Also, if you go over to Large Format Forum, I think Sandy still visits there. Good luck.

That's good to know. Thanks. As you said, it's really dilute. I have had great luck with it using minimal agitation but had mixed results in the Jobo drums (nothing awful, just okay sometimes and nice other times).

Baisao · Feb 24, 2016

MVNelson said:
I have done BTZS film test with pyrocat-mc in BTZS tubes with okay results at 1:1:100 but much better result with 1.5:1.5:100 .

That's positive to hear! Did Fred have you do a 4 min test for dilution too?

What temp are you using?

Rick A · Feb 24, 2016

I don't see how you arrived at 4 minutes at 21c. I looked over my old notes from using P-cat, nearly all my films came in around 15 minutes at 20c. If you use that as a base time and temp, raising the temp by one degree and adjusting for rotary (85%) you still need to either add time, or raise temperature, or both. You could increase dilution to 1.5+1.5+100 or 2+2+100 and test. At one time, Sandy had sent me a note about developing Ilford Ortho+ using 1+1.5+100, basically FP4+ without red sensitizer.

Baisao · Feb 24, 2016

Rick A said:
I don't see how you arrived at 4 minutes at 21c. I looked over my old notes from using P-cat, nearly all my films came in around 15 minutes at 20c. If you use that as a base time and temp, raising the temp by one degree and adjusting for rotary (85%) you still need to either add time, or raise temperature, or both. You could increase dilution to 1.5+1.5+100 or 2+2+100 and test. At one time, Sandy had sent me a note about developing Ilford Ortho+ using 1+1.5+100, basically FP4+ without red sensitizer.

This is a pre-test of sorts that VCS uses to determine the correct dilution.

I've been using Pyrocat-HD with FP4+ with great success for the past two years using minimal agitation and my times are in the teens. Again, this is a pre-test for BTZS as requested by Fred of VCS.

ic-racer · Feb 24, 2016

Tell us what test and you can have the answer. I good test for dilution is to ensure that the center of the negative is not under-developed from exhaustion. This test is done by exposing a sheet of film to a distant light source to produce an even exposure. The development is carried out and the processed film density is measured in the center and at all 4 corners. The density should be within ten percent. If the center is less dense then more developer is needed, and/or there is a fault with agitation.

Baisao · Feb 24, 2016

ic-racer said:
Tell us what test and you can have the answer. I good test for dilution is to ensure that the center of the negative is not under-developed from exhaustion. This test is done by exposing a sheet of film to a distant light source to produce an even exposure. The development is carried out and the processed film density is measured in the center and at all 4 corners. The density should be within ten percent. If the center is less dense then more developer is needed, and/or there is a fault with agitation.

This is a BTZS test being done by The View Camera Store. Details are in the first post.

Sandy responded on the Large Format Forum, which was very helpful.

MVNelson · Feb 24, 2016

Baisao said:
That's positive to hear! Did Fred have you do a 4 min test for dilution too?

What temp are you using?

I use 70 degrees and I do my own exposures for film test . I use my enlarger and Phil Davis' instruction In the BTZS book.

Baisao · Feb 24, 2016

MVNelson said:
I use 70 degrees and I do my own exposures for film test . I use my enlarger and Phil Davis' instruction In the BTZS book.

Thank you, sir!

MVNelson · Feb 25, 2016

Baisao said:
Thank you, sir!

The trick is to be able to get a .4 sec exposure at EV level 4 consistently on your enlarger baseboard ... Once you have that the rest is a piece of cake .

Pyrocat with BTZS Tubes - Dilution Question

Moderator

Privacy & Transparency

Privacy & Transparency