Strange behavior using Unicolor drum/base

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

I use the beseler drums and motor base. Because film is getting constant agitation with the unicolor and beseler motor base, adjustments in development times or greater developer dillutions are usually called for. You have made some time adjustment but you will need to decrease the time a little more to suit your liking.

I think you will find, on the average, most published times will be a bit too long. At least that has been my experience. As an example, the times given on the MDC for APX 100 sheet film in D-76 1:1 is on the order of 13 minutes. Using a Unicolor drum, my times are more like 7.5 minutes.
Even my smaller format films take far less time than those published. I don't do any fancy testing or anything. I just clip test to find a time that makes it look right and print well. Then, I write it down so I remember it and that's what I use for that particular film.

Could all be due to the color of your enlarger light. What 'contrast' or 'color' did you use when making your Zone VIII tests ala Picker?

Doesn't really matter anyway, just keep going with your results, sounds like you are doing all the right things!

Quote:

---

Originally Posted by Glenn Thoreson

I think you will find, on the average, most published times will be a bit too long. At least that has been my experience. As an example, the times given on the MDC for APX 100 sheet film in D-76 1:1 is on the order of 13 minutes. Using a Unicolor drum, my times are more like 7.5 minutes.
Even my smaller format films take far less time than those published. I don't do any fancy testing or anything. I just clip test to find a time that makes it look right and print well. Then, I write it down so I remember it and that's what I use for that particular film.

---

I started using a Jobo 4x5 / 5x7 drum on my Unicolor base that I modified to rotate only one direction. I had to do this because it wouldn't make a complete revolution with the larger Jobo drum. I find that with most films and developer combinations I have to process at roughly 50-60% of the normal time for normal contrast.

All,

Thank you for the replies and sharing your experiences with this setup. The reduced development times needed confirms what I have observed. I thought something was wrong in the way I was processing but it seems like I am on the right track.

Thank You.

Anil Bharucha