View Full Version : Film speed loss processing tri-x in xtol

Andrew Logan
6-Mar-2005, 00:50
I have some oldish Tri-X film ( the sort that came in 4x5 film packs) which has been properly stored, although it is dated 1984. I have just been trying to establish expansion and contraction curves using xtol diluted 1:1 in a Jobo CPA2 processor as described in athread on this forum. I have found to my surprise that the film speed with this combination appears to be only about 40!. When exposed at ASA 320, I reached a density of 0.1 above base density and fog only at zone V, implying underexposure of about 4 stops. I get the same results retesting, and exposing at ASA 80 and 160 also imply a real speed f ASA40. When I expose at ASA40 I get 0.1 above base+fog at about zone 1.5 suggesting I am not too far wrong. Is this the sort of speed loss I should expect, and is thefilm worth using or should I just dump it. The film is not fogged or otherwise unusable.

Bruce Watson
6-Mar-2005, 09:20
My EI for 4x5 Tri-X sheet (the older 4164) is 320 in XTOL 1:3, 20C, six minutes, Jobo 3010 tank, 30 rpm on a CPP2. I'm developing for scanning, so I'm about 1 stop less dense (my zone IX is about 1.3) than you would want for darkroom printing.

You shouldn't expect any speed loss from XTOL; it normally gives people rated speed or a bit more. The same combination above, with HC110-H gave me an EI of 250, for example (5 minutes instead of six, but with considerably more density (my zone VII was about 1.3).

If you are getting EI 40, something is seriously wrong. The biggest suspect is the film. ASA 400 films aren't known for their longevity in storage, and yours is 20 years out of date, more or less.

Try a few sheets of modern Tri-X. If you get the same results, it's not the film...

Donald Qualls
6-Mar-2005, 11:37
Assuming your Xtol hasn't gone bad on you (develop some known good film to check it), whas you're probably seeing is just loss of speed from the film aging. Like Bruce, however, I'd be surprised to see speed loss exceed two stops (though many folks like to expose their Tri-X at up to one stop slower rating than the box shows, which would be three stops -- you're still a stop below that).

I'm inclined to suspect your developer. Try a sheet or two of that old Tri-X in HC-110 or fresh D-76 to get a baseline, or try some other film in your Xtol to be sure it's still good...