Uneven Development, 8x10 film and Jobo Please Help

[gerryyaum]

Am using the 5 sheet expert tank in my Jobo to develop my 8x10 Tri-x shot in Asia recently. I am having a problem with uneven development along the bottom edge of the negative. I have tried the following to no effect:

-added more chemistry up to 600 ml (D-76/Water)
-Changed the agitation setting from 4 to P
-Flipped and moved the film around in the expert tubes, tried it facing up and down and lower and higher in the tube.

The development time and temp that gives me the tonal range I like is 20 minutes with 370ml of D76 and 230 Water at 24 C

This uneven development is making me go a bit bonkers, any suggestions would be greatly appreciated...here is a sample of the problem, look at the lower edge.

Thanks Gerry

http://3.bp.blogspot.com/_DBy0KG-ZZ...L1AkY0ado/s1600-h/Boon-1-300dpi-adapt-700.jpg

 

[Venchka]

If you are developing 5 sheets of 8x10 film you are exhausting the D-76. Try Xtol using 100ml/sheet + whatever dilution will work in that tank.

20 minutes at 24C is an awfully long time. Another indication of insufficient developer. I process HP5+ and Tri-X 320 in Xtol 1:3 for 10 minutes at 20C.

 

[ic-racer]

Twenty minutes! I'd try using more developer or a different developer. 5 sheets of 8x10 require around 1200 cc of D76.

 

[erikg]

I never use any less than 1 liter of developer for 5 sheets of 8x10 film.

 

[erikg]

Oh, and be sure to level out the tube, that can cause uneven development.

 

[Venchka]

Thanks for the confirmation, Y'all!

A question: is the emulsion facing the center of the tube?

I use a 3010 and a Beseler base for 4x5. Ample Xtol. Even negatives everytime. Same for roll film in a Jobo tank.

 

[davekarp]

For more confirmation of the above suggestions: http://www.largeformatphotography.info/forum/showthread.php?p=474032

I have been using my 3005 on a Beseler base to develop whole plate and 5x7 film. Following the above recommendations has resulted in very nice negs. I have been using 1L of developer.

 

[Ronald Moravec]

With all Jobo film tanks, I turn the speed up full for pour in and for the first 30 sec after developer is fully introduced which I pour in as fast as it will go. Second 30 sec is 3/4 speed, then I go to 4.

Uneven development is almost always insufficient initial agitation.

If developer is exhausting, then developed in two charges of developer changing around half way.

 

[TheFlyingCamera]

HMMMMMM. I do all my sheet film in expert drums, with speed at the lowest possible speed the Jobo can deliver without being off, and have never had the problems you're indicating. I use 500 ml of Pyrocat HD 1:1:100, and for FP4+ I'm at 11 mins, Fomapan 200 is 13 mins. That dilution of D76 is awfully potent - you may be overcooking things and getting the unevenness as a result ( I can't see your sample right now as the firewall at the office blocks any blog sites ). The areas of the film that make contact with the sides/bottom of the drum may be blocking or channelling developer. I'd try thinning out your developer and increasing total fluid volume, and slowing down to minimum. Running the drum at 4 or higher, for b/w film, seems like gross over-agitation to me.

 

[Venchka]

Once upon a time Kodak said, "8 oz. D-76 per 8"x10 of film". They have since changed that a bit. It's still good practice. Using D-76 1:1 that works out to 80 oz. of fluid in a Jobo tank. Far too much liquid. That's why I use Xtol instead. 100ml Xtol per 8"x10" of film. Even at 1:3 I can process 10 sheets of 4x5 in my 3010.

 

[Mahler_one]

I echo what TFC said above. However, I have never developed more than 3 sheets of 8x10 at a time in the expert drum ( worried about over-loading the motor ), and 3 only rarely. Eight ounces of DDX, 1 plus 9 or 1 plus 11 per sheet. Agitation as per TFC, never faster. So far I have never seen the problems alluded to by gerry. If you find the cause of the film developing marks that you have referenced please let us all know! Thanks.

Ed

 

[RJS]

If you are referring to a very slight change in density at perhaps the bottom 1/16 or so of your print, I managed to obtain this effect with my Sinar Norma due to a 'tight' bellows. It wasn't consistent but apparently with a bright background like yours a bit of light was being reflected off the bellows right at the edge. The old Calumet with a rotating back and 5X7 bellows never did this. Just a thought.

 

[Dave Dawson]

RJS may have a vey valid point......Try this, take two shots and load them into the drum, one normally loaded the other upside down. Next load two sheets of film into a holder, one normal and the other upside down. This will tell you if it's the drum, development or the camera/holder.

Cheers Dave

 

[gerryyaum]

Thanks everyone for all your help, greatly appreciated.

Gerry