Pyrocat HD, how many 8x10's ?

[David Brunell]

I am about to mix up a batch of 1:1:100 Pyrocat HD. How many 8x10 negatives can I develop with this 1000ml working solution? I have (6) negatives and wanted to try to get them all done in sets of (2) by tray method using the same batch of developer. I have only done (2) per batch prior to this point and want to see if I can make better use of the chemicals. Same goes for the fixer (TF-4 Archival Fix) For what is worth I am using a weak citric acid stop bath so I don't think that should be a concern.

Thanks.

[Ken Lee]

According to http://www.pyrocat-hd.com/pdf/FormularyHDGlycol.pdf: (emphasis mine)

When developing with rotary processing, either Jobo or BTZS type tubes, use a minimum of 75 ml of the standard working solution
per sheet of 4X5 film, (minimum of 250 ml of working solution for a sheet of 8X10 film)

Once mixed in water and exposed to air, it oxidizes. I wouldn't use it more than once.

The recommendation above translates to 4 8x10 sheets per liter of solution minimum, so another option is to mix 2 liters and develop your 6 sheets all at once. I have routinely developed 20 or more 4x5 negatives in 2 liters of 1:1:100 solution.

Given the cost of 8x10 film, saving a bit on developer (especially one that is fairly affordable) may not be the best approach. We probably spend more money on 1 gallon of gas (or 1 liter of petrol) just driving to the scene

Citric acid is great: no smell. With an alkaline fixer like TF-4 we can also use plain water, but having just a touch of acid helps arrest development immediately.

[Gem Singer]

Ken types faster than I do.

I was about to tell you the same thing.

Use 2 liters of working solution for 6 sheets of 8x10 film.

(That's only 20ml soln "A" and 20ml soln "B").

[David Brunell]

Thanks Ken...I actually picked up the citric stop bath from your great website...So for tray developing at that concentration I should assume by "250 ml of working solution for a sheet of 8X10 film" I can get (4) with 1000ml's and (8) with 2000ml's Max, correct?

[David Brunell]

Thank you Gem as well.

[Ken Lee]

Yes, that should work, according to the instructions, but as Gem pointed out (and I intimated) you'd be safer doing 6 8x10's rather than 8, because 8 is pushing the limit. It's helpful if you mix your developer last, and use it right away.

[David Brunell]

Sounds good, thanks again.

[jp]

If you use 1-2 L in a tray, the 3,4 and 5,6 sheets will be developed notably weaker as the develop gets used up and oxidized. You could start with 1L, do two sheets, replace 500ml of it, do two more sheets, replace 500ml more, and do the last two sheets and it would be more consistent; not as consistent as fresh developer for each two sheet batch though.

A minute in generously full tray of water-only stop bath will be fine. Tray a couple sheets and see.

[David Brunell]

If you use 1-2 L in a tray, the 3,4 and 5,6 sheets will be developed notably weaker as the develop gets used up and oxidized. You could start with 1L, do two sheets, replace 500ml of it, do two more sheets, replace 500ml more, and do the last two sheets and it would be more consistent; not as consistent as fresh developer for each two sheet batch though.

A minute in generously full tray of water-only stop bath will be fine. Tray a couple sheets and see.

That is a great idea. I agree, that would certainly assure a more consistent result.