HP5+ 35mm and Perceptol at 1:3 - Minimum Developer Quantities

[pentaxuser]

I have been getting pretty good negs and prints with HP5+ at EI 250 and Perceptol stock solution. However I'd like to try it at 1:3 dilution. A thorough search of threads has revealed a general consensus that 1:3 gives more sharpness without sacrificing fine grain. Most prints would be at 5 x 7/8 inches with occasional 8 x 10.

A couple of subscribers agree quite closely on dev times, agitation and temp. These being around 18 mins at 24 degrees C, slow but continuous initial agitation of 30 secs, followed by 1 inversion every 30 secs.

This sounds about right to me and it's waht I aim to do but leaves one question which I am sure was answered in the other threads but I am unsure of the answer.

It is this: I use a Jobo tank for inversion and for one film it takes 240ml. If I use 1:3 this means 60ml of Perceptol stock only.

Can I take it that this will be enough? I am aware that there are minimum quantities of full strength developer needed for any film below which you shouldn't go.

Logically as the tank can only hold 240ml and 1:3 is OK then I'd imagine that 60ml must be OK, otherwise the tank has limitations as to its use for dilute developer.

However confirmation that this is OK would be helpful. Especially from those who use this combination as described above.

Thanks

pentaxuser

PS I am surprised that Ilford only list a development time for stock solution at EI 250 although it covers 1:1 at EI 320 and 1:3 at box speed which surprises me, given that Perceptol is a speed reducing developer.

Maybe this is on Ilford's "to do" list. It certainly would be helpful if it was.

 

[Lachlan Young]

When you dilute Perceptol the quantity of Sodium Chloride and Sodium Sulphite drop below the level at which they are sufficiently solvent to reduce the film speed.

Hope this helps,

Lachlan

 

[pentaxuser]

When you dilute Perceptol the quantity of Sodium Chloride and Sodium Sulphite drop below the level at which they are sufficiently solvent to reduce the film speed.

Hope this helps,

Lachlan

Thanks Lachlan. Yes it does help as far as helping to explain the rationale of why it should be EI 250 at stock then 320 at 1:1 and finally box speed at 1:3. However it raises other questions such as why bother with any dilutions AND lower the box speed? If such dilutions as 1:3 mean that box speed is correct then what's the difference between Perceptol at box speed and say ID11 for HP5+ in terms of grain and sharpness?

Does it suggest that if I want the benefits of Perceptol for a film like HP5+ then I need to stick to stock solution and EI 250 and am I fooling myself into believing there is any benefits of less than box speed AND dilution.

However folks I don't want this explanation by Lachlan to divert the thread solely onto what he has been good enough to provide and to the questions it raises.

So in the meantime folks I have exposed the film at EI 250 and still want to hear about minimum quantities of developer needed for a 1:3 dilution.

pentaxuser

 

[Leon]

PS I am surprised that Ilford only list a development time for stock solution at EI 250 although it covers 1:1 at EI 320 and 1:3 at box speed which surprises me, given that Perceptol is a speed reducing developer.

Maybe this is on Ilford's "to do" list. It certainly would be helpful if it was.

I dont get an ei of faster than 250 with hp5 in perceptol 1:3

I dont know about exact quantities needed, but I'm sure you'll be fine with your amount ... for developing one 35mm film, I use approx 300 ml of working solution and have never had any problems.

 

[pentaxuser]

I dont get an ei of faster than 250 with hp5 in perceptol 1:3

I dont know about exact quantities needed, but I'm sure you'll be fine with your amount ... for developing one 35mm film, I use approx 300 ml of working solution and have never had any problems.

Thanks Leon. I am sure it'll come as no surprise that yours was one of the threads on the process as described in my original post.

So if I have understood your reply, you'd get 75ml of Perceptol stock whereas my tank restricts me to 60. Actually it will hold a little over 250ml at a push so maybe I'll go for 64ml of stock. 11ml shouldn't be critical.

pentaxuser

 

[rst]

I do get pretty good results rating it at 250ASA and developing it in Perceptol 1+2 @ 24°C for 12 minutes 4 rotations in the first 10 seconds of every minute.

Regards
-- Ruediger