high speed 4X5 film: HP5/Microphen vs. TXP/Diafine?

[Henry Carter]

For 4X5 photography I occasionally resort to hand-held press style photography.

In low light I have been pleased with HP5 rated at 1600 and developed in Microphen.

Unfortunately regular 400 speed Tri-X is not available in sheet film. How well does its cousin, Tri-X sheet film (TXP 320), react to pushing? Would Diafine be the way to go with TXP? What useable speed do you acheive with Diafine? The 'massive development chart ' suggests rating TXP @ 1000 to 1200.

 

[John Sparks]

I found TXP 320 to have a real speed of about 160. I don't think you would like the results pushed, it will have really contrasty highlights with rather mushy shadows. On the other hand, I find Tmax 400 to be the fastest of the "400" speed films that I have tried (which is all the 400 speed films from Ilford, Kodak, Fuji and Afga). I rate it at 500 or 640 for regular, non-pushed photography (about twice the 250-320 I usually use for HP5). I find I get the highest speed rating in TmaxRS developer (Microphen is almost as fast, but grainer--not really a problem for 4x5). Tmax 400 in TmaxRS would be my first choice for a high speed 4x5 film.

 

[Henry Carter]

Thank-you John. Though I have shot 4X5 TXP rated at 160 and obtained excellent results with PMK Pyro, I have not used any other Kodak sheet films. Exposed at 160-200 and developed in PMK Pyro TXP and HP5 are indistinguishable.

As a high speed alternative pushing TMY certainly sounds like a possible alternative to pushing HP5, and I would be interested in suggestions regarding appropriate developers for pushing up to 1600 (TmaxRS, Microphen, Accufine?). As you point out, grain is not really a major issue with 4X5!
Regards,
Henry

 

[John Sparks]

I have had the best results pushing film with TmaxRS. I'm mostly using medium format these days and it gives finer grain and similar speed to Microphen. I had about given up hope with finding a usable developer from Delta 3200 until I happened to try TmaxRS, a miracle combination for me. I have used a lot of TMY in TmaxRS and a little in Microphen. I prefer the TmaxRS, but with 4x5 the grain difference is probably unnoticable. I haven't used Accufine in 20 years, do they still make it? From things that I've read, I would expect TmaxRS or Microphen to do a better job, but I haven't tried it with anything except 35mm Tri-x and that was a long time ago.