Pyrocat-HD vs MC Vs. Rollo Pyro / ABC+ for use in Jobo

[Jim Galli]

I have done thousands of sheets of 8X10, 5 at a time using 850ml. The one thing you should research though is with FP4, HP5, PlusX, Tri-X, and even Efke 100 I always use 2:2:100. I use 1:1:100 on very slow contrasty film like Aerial Panatomic X where I'm actually trying to restrain development.

I agree, go shoot some stuff in the back yard that doesn't matter for your first trials.

[Drew Wiley]

Some of that stuff in the back yard is liable to eat me if I'm not careful! I just got done taking my big commercial weed whacker to it. If I don't keep things buzzed down this time of year, even the carnivorous St.Augustine grass is likely to strangle the porch cat in his sleep. But hidden from such terrors in my darkroom, back when I did experiment with film processing in drums, I preferred to fine tune dev activity via significant RPM options, and not just via time, dilution, and temp. My own gear-motors on the roller devices are set up to run at a considerable lower speed, if necessary, than say, something like a Jobo, which even at the lowest speed, seems awfully revved up. But I get more consistent results tray method.

[JimL]

One thing you can do to reduce the load on the Jobo's motor is to rotate in one direction only. Flip the little white reversing arm by the drive gear out of the way. I use mine this way with Expert drums and the lack of reversing doesn't seem to affect developing evenness as far as I can tell.

[Tim V]

Thanks all,

I’ll certainly do some tests first and probably start with 4 sheets rather than 5.

Jim Galli, when mixing HD at 2:2:100, how do you calculate times compared to 1:1:100 dilution? I was thinking this could be a good way to go too in order to combat exhaustion of chemistry, but don’t know where to start with regards to time. I’m currently using HP5+. Does Sandy give a formula for this?

EDIT: In an effort to find this out for myself, I revisited Sandy's article on The Unblinking Eye: https://unblinkingeye.com/Articles/P...at4/pcat4.html

Looking at Figure 20. HP5+, Pyrocat-HD mixed 2:2:100, processed for approximately 7.5mins @ 72 degrees F. should get me a CI of 0.52, which is desirable for VC silver printing. While I trust this is a good starting point, does this sound right to you? Seems a great place to start for processing 5 sheets at a time with 1L of total working solution–so more than needed as a safeguard, rather than bare minimum–so not to overload the motor and guard against exhaustion. Sandy states that with this dilution you can get away with 20% less working solution per sheet.

[Jim Galli]

Thanks all,

I’ll certainly do some tests first and probably start with 4 sheets rather than 5.

Jim Galli, when mixing HD at 2:2:100, how do you calculate times compared to 1:1:100 dilution? I was thinking this could be a good way to go too in order to combat exhaustion of chemistry, but don’t know where to start with regards to time. I’m currently using HP5+. Does Sandy give a formula for this?

EDIT: In an effort to find this out for myself, I revisited Sandy's article on The Unblinking Eye: https://unblinkingeye.com/Articles/P...at4/pcat4.html

Looking at Figure 20. HP5+, Pyrocat-HD mixed 2:2:100, processed for approximately 7.5mins @ 72 degrees F. should get me a CI of 0.52, which is desirable for VC silver printing. While I trust this is a good starting point, does this sound right to you? Seems a great place to start for processing 5 sheets at a time with 1L of total working solution–so more than needed as a safeguard, rather than bare minimum–so not to overload the motor and guard against exhaustion. Sandy states that with this dilution you can get away with 20% less working solution per sheet.

Sandy's number sounded conservative to me so I checked the "massive development chart at digitaltruth photo and for 2:2:100 in a Jobo they say 10 and I usually just default mine to 10 1/2. Again, that's seat-of-the-pants long time user. But I rarely do HP5 film. Most often for me is Efke 100, Aerial REcon Plus X and Aviphot 200. All of those are either 10 or 10 1/2 mins in my processor with 850ml. Lots of good keepers over the years.

[Andrew O'Neill]

I've been developing HP5 in 2+2+100 since 2003. My N time is 10:30 @ 21C. Continuous agitation. These negatives allow me to print in silver or carbon transfer.

[Jim Galli]

I've been developing HP5 in 2+2+100 since 2003. My N time is 10:30 @ 21C. Continuous agitation. These negatives allow me to print in silver or carbon transfer.

Good affirmation. Thanks.

[onnect17]

I don’t remember where I read a good starting point was sqtr(2), ie 1.4142.


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[Tim V]

Brilliant, thank you! Just the confirmation I was hoping for!

Thanks all who have replied, it’s really helpful.

I've been developing HP5 in 2+2+100 since 2003. My N time is 10:30 @ 21C. Continuous agitation. These negatives allow me to print in silver or carbon transfer.