Dense negs using Pyrocat

[sdivot]

Hi,
Maybe Sandy can address this.
I expose two negs (FP-4, 4x5) in an identical manner. One is developed in D-76, the other in Pyrocat HD. They both print well on silver paper. The Pyrocat neg is much denser, however. The exposure times under the enlarger are something like 3 times as long as the D-76 neg. I can live with the longer exposure times, but my goal is to make dual purpose negs. I print in silver and platinum.
My pt/pd printing times with the Pyrocat neg is in the neighborhood of an hour! My UV unit is homemade using 12 20w bl bulbs. It may not be very powerful, but come on!
I'm almost positive I'm not overexposing the negs.

My Pyrocat development is 1-1-100, stand development, 1 hour in an upright position, with 4 agitations of 10sec. I got this from one of many online posts I've read. I also tried a dilution 1-1-200, and 1-1-400. They are both a little flat, especially for platinum. It's my understanding that development time will affect density a little, but it will mostly affect contrast. The original Pyrocat neg (1-1-100) is nice and contrasty, but so dense!

I know this will require some more trial and error, but can someone give me some direction? What am I doing wrong?

Thanks,
Steve

 

[Peter Schrager]

DEnse?

Try the FP4 at around 12-13 minutes in Pyrocat-HD Will give you good negatives for Platinum.
An hour you said? Who has an hour to print? Even my old Trix film with a BP+F of about .22 print in 35 minutes. I don't think you're gaining all that much by stand
and the plat. process. Spend your time photographing; buy the Arentz book. There are MANY ways to skin a cat i.e. he has some great dev. times in the book for many films and
several different developors. D-76 makes great Plat. negs. Sometimes this dual neg BS is a little blown out of proportion...try it and see. Sometimes it works and sometimes it aint NEVER going to work. You can always make 2 negatives!!
Best, Peter

 

[sanking]

Hi,
My Pyrocat development is 1-1-100, stand development, 1 hour in an upright position, with 4 agitations of 10sec. I got this from one of many online posts I've read. I also tried a dilution 1-1-200, and 1-1-400. They are both a little flat, especially for platinum. It's my understanding that development time will affect density a little, but it will mostly affect contrast. The original Pyrocat neg (1-1-100) is nice and contrasty, but so dense!

I know this will require some more trial and error, but can someone give me some direction? What am I doing wrong?

Thanks,
Steve

Steve,

Devlopment time will affect both overall density and contrast. As you increase time of development contrast rises, but at a certain point maximum CI is reached, and at that point further time in the developer simply add overall density in equal amounts at every point on the curve.

Your time of one hour of stand development in FP4+ using the 1:1:100 dilution is much too long. Reduce your times to about 20 minutes with this dilution and try again.

My own tests, using FP4+ and a 1:1:150 dilution of Pyrocat-HD, show that you should get plenty of contrat for printing on silver VC papers and in Pt./Pd. using about a 3:1 ratio of Pallaidumlatinum, with 30 minutes of development. This is with extreme minimal or semi-stand agitation. I do not recommend full stand development because of the risk of uneven develoment.

Sandy

 

[sdivot]

Sandy,
Thanks for the reply. Can you give me a starting time for 1-1-150 semi-stand agitation using FP-4? Again, I know it will require some experimentaion for my own personal methods, but a starting point would sure help.
Semi-stand involves agitation every 3 minutes. Is this correct? Can I do this in trays, or standing up in tubes like stand development?
Thanks,
Steve

 

[sdivot]

Sandy,
Just to clarify, the dilution I used in my initial (very dense) neg WAS 1-1-150, not 1-1-100 as I wrote before. Sorry for the typo. One hour still too much time? I suspect so.
I think I will switch to semi-stand as well.
Can you suggest times for this 1-1-150 dilution?
Steve

 

[sanking]

Sandy,
Just to clarify, the dilution I used in my initial (very dense) neg WAS 1-1-150, not 1-1-100 as I wrote before. Sorry for the typo. One hour still too much time? I suspect so.
I think I will switch to semi-stand as well.
Can you suggest times for this 1-1-150 dilution?
Steve

Sorry, I amended to first message to provide the information. For semi-stand develoment of FP4+ try about 25-30 minutes at 70F with the 1:1:150 dilution.

Sandy

 

[vet173]

I'm having good results using sandys recomendation of 1.5:1:200 for semistand development. 23 min @72f. 1.5 min inital agitation, 2 asa agitations with 12 min left, for printing on Azo.