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John
26th February 2009, 08:00 PM
Whilst Prescysol is a topic of discusion I thought I would ask about the recommendation of "We recommend for ultimate control and results that you perform standard tests to determine film speed and development times".
The question is, is the tests the same as with any other film developer combination or is there a procedure that takes into account the staining etc.
John
Lincoln

Trevor Crone
26th February 2009, 08:26 PM
John, personally when I started using staining developers such as Prescysol, PMK pyro, etc., I test film speed and standard development time as I would using so called standard developers. I make no special allowance for the stain.

Dave miller
26th February 2009, 08:34 PM
I agree with Trevor, just test as normal.
I must admit though that as I have been happy with the results that I have obtained with Prescysol at the recommended times, I have never tested for film speed or development times. I have however played around with dilution since this has quite an effect on contrast.

John
1st March 2009, 05:17 PM
Many thanks to Trevor and Dave, it looks like the dilution tests is the way forward.
John
Lincoln

Bill
1st March 2009, 06:07 PM
I must admit though that as I have been happy with the results that I have obtained with Prescysol at the recommended times, I have never tested for film speed or development times. I have however played around with dilution since this has quite an effect on contrast.

Would you like to elaborate further on that Dave?

I am using Prescysol EF and would be interested. I had the impression (wrongly by the look of it) that what you got is what you got.

Bill

Dave miller
1st March 2009, 06:48 PM
Simply that increasing the dilution increases the contrast of the negatives. Whether it makes any difference to your prints, only you will be able to judge. Similarly changing the developing time, or varying the film speed used may have an effect. Peter gives his suggestions for development times, which we all seem to have accepted without testing for ourselves, because it works. Does that mean varying the time will not improve the results. Without testing I don't know.

Peter Hogan
4th March 2009, 04:10 PM
Actually Dave, it's decreasing dilution that increases contrast! That means adding more of the A and B solutions to the water. This is the main way of changing contrast. Another is to increase agitation. Increasing time will have very little effect as the dev is self-limiting to a point. Increasing time will increase shadow detail but not affect highlights so much.
Prescysol is such a forgiving developer that the times suggested will almost always give printable negatives. If you're a sufficiently advanced photographer and like a particular 'look' in your negs you can fine tune. Les, for example, likes very contrasty negs and often mixes EF at 5:5:100. I keep telling him he's wasting developer, but you know Les...

Ag-Bromide
4th March 2009, 04:46 PM
My regular developer is D-76 diluted 1:1, but quite recently I had a film developed in Pyrocat HD by one of our forum members, so I am considering Prescysol EF due to it`s availability as a liquid concentrate and for economy. I will use it as recommended to start with though. I am hoping that the negatives will print well on graded papers such as Ilfospeed, Galerie, Kenthene, Bromide and Kentona.

Dave miller
4th March 2009, 04:57 PM
My regular developer is D-76 diluted 1:1, but quite recently I had a film developed in Pyrocat HD by one of our forum members, so I am considering Prescysol EF due to it`s availability as a liquid concentrate and for economy. I will use it as recommended to start with though. I am hoping that the negatives will print well on graded papers such as Ilfospeed, Galerie, Kenthene, Bromide and Kentona.

I print on graded papers without any problem, although on none of those you list.

Dave miller
4th March 2009, 05:03 PM
Actually Dave, it's decreasing dilution that increases contrast! That means adding more of the A and B solutions to the water. This is the main way of changing contrast. Another is to increase agitation. Increasing time will have very little effect as the dev is self-limiting to a point. Increasing time will increase shadow detail but not affect highlights so much.
Prescysol is such a forgiving developer that the times suggested will almost always give printable negatives. If you're a sufficiently advanced photographer and like a particular 'look' in your negs you can fine tune. Les, for example, likes very contrasty negs and often mixes EF at 5:5:100. I keep telling him he's wasting developer, but you know Les...

You are, as ever, quite right; but I knew what I meant. :) I put more stuff in the water is what I do!

I agree that increased agitation can increase contrast, but this isn't peculiar to Prescysol.

Ag-Bromide
4th March 2009, 06:48 PM
I print on graded papers without any problem.I`m glad to read that, thanks.

John
5th March 2009, 12:19 AM
I have completed a simple/coarse test with FP4 developed in Prescysol EF involving a white towel (highlight with detail) and black face cloth (black with detail) and a grey card. Laid them on the floor and photographed them on to three films. Developed them as follows
Film one 1.1.100
Film two 1.2.100
Film three 1.3.100
The last one is best for me as the neg printed on grade 2.5 . I may be doing something wrong in my method of developing the film but 1.3.100 seems to correct it. (for me) Anybody what 45 negs of a white towel etc?
John
Lincoln

Dave miller
5th March 2009, 07:23 AM
I seems like time and material well spent.