This all refers to 4x5 sizes. Since I can be a cheap bastard, I love Diafine, and have been using it with Tri-x For a while with great results. Then the cheap bastard in me sees J&C 400 for about half the cos of Tri-Xt and gets excited, but can find no reference to anyone ever using it in Diafine. My J&C Classic 400 arrived today, so I ran my own little test. Here are my results. Since I don't own a densitometer, or have a darkroom easily avaiable, I ran my test by shooting off a scene at 400, 800 & 1600 on each film, and then scanned them on my Epson 2450 using Vuescan with all auto balanceing turned off so that each negative got the same amount of exposure. Then compared that image, and one done with just levels applied in Photoshop to the image and eyeballed it from there. The top images in each exaplme JPG is the strait scan, and the bottom are after just a simple levels. Scene was incident metered outside with a Luna Pro SBC. Dark interior that I included in the scene metered around 4 stops less then the outdoors. Example images; 400 ISO, 800 ISO, 1600 ISO My own observations; · Shooting at 400, the TXP320 seems a little faster, but the J&C image seems to be better with a minor tonality issue that I've always had with the tri-x. One comparison sheet isn't much though, and I'll have to play with this some more. Maybe have to rate it a hair slower to get the shadow detail that I'm used to. · Stick with tri-x when going beyond 400. Tri-x @ 1600 was still a decent negative, the j&c @ 1600 was thin enough that holding it up to the light in my basement after processing had it do that thin negative trick where it looks like a positive. The tri-x @ 800 seems somewhat close to J&C @ 400.