Jobo starter processing times for FP-4

[badbluesman]

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.

[Leigh]

The general rule for rotary processing is 15% less time than for other methods.

- Leigh

[Lachlan 717]

Have you consulted the Massive Dev Chart?

[welly]

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]

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".

[JeRuFo]

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

[koh303]

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.

[Noah B]

I used fp4 rated at 100 in XTOL 1+3 at 12.5 mins and got great results with my jobo.