All,

I am using unicolor 8x10 print drum to develop 4 4x5 on a uniroller as described in the article section of this forum.

The film is Tri-x 320TXP and the developer is xtol 1:1 (125ml:125ml). I used distilled water for mixing the developer and any water added to make working solution.

Kodak technical data sheet for xtol (publication J-109, March 2008) suggests 7 1/4minutes in "Rotary Tubes." I used Stouffer's 21 step wedge sandwiched in the film holder to establish my ISO of 200 (which gives me tonal separation down to Zone II). However, using the published data blew the highlights away. Anything above Zone VI is paper white. I am following Fred Picker's method in establishing my "proper proof" times.

I ran a second test with 30% less development time (68F at 5 min) at ISO 200 and I now have noticeable density above paper white on Zone VIII. I may reduce it by another 5%.

The question is, has anyone noticed similar behavior where kodak's "rotary tube" times may be too long? I wonder what type (s) of rotary tubes they are referring to.

To be consistent, I processed 4 sheets at a time for both tests. My motor base is uniroller model 352. This particular base rotates back and forth and the speed can not be adjusted. I can live with it but I am just wondering if others have experienced the need to back off in development significantly.

The enlarger is Omega D2 with Zone VI VC cold light head and the paper is Ilford MGIV RC pearl.

Thanx.
Anil Bharucha