How many 8x10 sheets can be developed at a time in an expert tank?
I have used the Jobo CPP 2 for a long while, and have the up-dated motor and circuit board. I have always been careful not to over stress even the newer motor and circuitry by limiting the number of 8x10 sheets developed in the expert tank at one time to a maximum of two-and therefore the solution volume is 500 cc or less.
However, I am about travel to the Western USA where I hope to take many exposures. I am curious as to whether or not it is "safe" to develop 4-5 sheets at one time. The added weight of the solutions will make the expert drum quite heavy. I always use my right hand to help lift the drum, and so I do not see the added weight as being a problem whilst using the lift. However, I am curious as to whether or not other Jobo users who develop 8x10 sheets in their expert tanks have had any "problems" caused by the added weight of solutions while developing mutliple sheets. How many sheets can one do at a time before there is added risk of burning out the motor? Indeed, IS there any risk? The expert tanks have room for 5 sheets at a time. Consequently, Jobo must have intended their units ( at least the newer ones with the updated motor and circuits ) to be able to handle the added weight. Help and advice appreciated.
5, do 500ml for the first half of development and 500ml of fresh developer for the second half. There, now you can sleep tonight!
I know what I want but I just don't know how to go about gettin' it.-Hendrix
I use 570ml for 5 sheets in that drum. The maximum recommended for the CPP2 is one liter. My CPP2 turns 10 years old this year, it still runs and looks like new. I do all my rollfilm with a volume of 970ml.
If yours strains with 500ml, perhaps your transfer gear needs to be lubricated.
Last edited by ic-racer; 09-15-2011 at 09:36 PM. Click to view previous post history.
Bill...I have considered that approach. However, I am not convinced that using two 500 cc sequences will have the same effect as using 1000cc. There might well be chemical changes that would influence the results. I have done no film testing that would allow me to use the divided volume approach with confidence. Have you used such an approach, and if so, what developer and what film? It might be the case that some developers will "allow" "divided volumes", but other developers might not.
I am using FA-1027 from Formulary, or PCHD using Sandy's instructions. Once in a while I will use DDX, but not very often. Usually HP5 and TriX depending upon my whim, and the possible subject.
Last edited by Mahler_one; 09-15-2011 at 10:09 PM. Click to view previous post history.
Reason: Added information
Thanks very much for the reassurance ic. My unit does not strain at all with 500cc, and I lubricated the gear a few months back. Perhaps I will fill up the expert tank with the requisite volume, and see how the unit performs. Appreciate the note.
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Also, wild bill's suggestion is totally valid. I process some film with Rodinal 1:100 and use the Jobo Tempering bath to hold enough bottles for up to 7 changes of developer: http://www.largeformatphotography.in...ad.php?t=23322
Originally Posted by Mahler_one
In terms of temperature and volumes, the Jobo works best with something like T-max developer (or a Tentanal equivelant that is probably no longer available). That will do 5 sheets with 570ml at about 6 min at 24 degrees C in the 8x10 expert drum.
Last edited by ic-racer; 09-15-2011 at 10:24 PM. Click to view previous post history.
Yes, Ok with Rodinal...but how about the other developers Ic?
I followed your link...very impressive work Ic, and nicely done and explained.