View Full Version : Jobo starter processing times for FP-4
badbluesman
6-May-2013, 19:07
I am going to start shooting FP-4 Plus in 5x7 sheets, due to the cost and lack of availability of T-MAX. I normally process my T-MAX 5x7 in a Jobo, using X-Tol developer diluted 1:2 at 24 degrees Celsius (75 F). My times are 6.5 minutes for TMX 100 and 5.5 minutes for the new, improved TMY 400. I vary the dilution for N+1 (1:1) and N-1 (1:3), without changing the time.
I am just looking for a ballpark first-try start time for FP-4 Plus. Any example would be helpful; I can extrapolate and test from there. If anybody out there has ever processed both FP-4 and TMAX in the same developer, you might be able to give me an idea how far apart they are (or how similar they are).
Thanks in advance.
The general rule for rotary processing is 15% less time than for other methods.
- Leigh
Lachlan 717
6-May-2013, 21:30
Have you consulted the Massive Dev Chart?
The general rule for rotary processing is 15% less time than for other methods.
- Leigh
Dumb question - BTZS tubes would be included in this general rule for rotary processing, correct?
Lachlan 717
6-May-2013, 23:21
Dumb question - BTZS tubes would be included in this general rule for rotary processing, correct?
Yup.
It's usually defined as "continuous agitation", rather than "rotary processing".
My time for TMX(4x5) is 7m20s at 21 degrees C (70F) in XTOL 1:1 and 6m30s for N-1. I don't do exact film testing, though. I only shot a few different shots in a controlled environment and tried to get the film looking right.
I got a starting time of 7m30s of someones website also by extrapolation, which is the same time that kodak gives for rotary processing of TMX 120. (http://www.kodak.com/global/en/professional/support/techPubs/j109/j109TableRollFilms3.jhtml).
If I extrapolate from that chart I'm getting 4m30s at 24C in XTOL 1:1 for FP4. I only ever change time and not dilution, so I can't give you a conversion to 1:2.
Edit: Scratch my extrapolated time, that can't be right if you look in de massive dev chart and to what people say in this thread : http://www.largeformatphotography.info/forum/showthread.php?21706-xtol-dev-times-with-fp4
For FP4 - MORE time then whatever the massive dev chart says...
Regardless of continuous agitation, FP4 needs more time then listed with pretty much every developer i have ever used, though i have never used Xtol.
I used fp4 rated at 100 in XTOL 1+3 at 12.5 mins and got great results with my jobo.
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