[LargeFormat] Jobo CPE and E6 s step process

[Pete Caluori]

From: "mark blackman" <mark.blackman1@btinternet.com>
Date: Mon, 2 Sep 2002 06:31:16 +0100

I've a quick question: Jobo recommend the final wash phase (before
stabilising) involves 10 water changes. Does this water have to be at 38
Centigrade? In fact, does the temperature matter at all?

Greetngs Mark,

I've processed quite a few sheets on the JOBO and would offer the following 
considerations.  Personally I think the temperature does matter, but that's 
a matter for interpretation.  I do not consider +/- 5 degrees F to be 
significant in the final wash.

I believe your wash will be more complete at a higher temp. vs. a lower 
temp.  The emulsion will swell considerably under the 38C processing temp 
and if you shock it with "colder" water I would think that the emulsion 
could be damaged.  Note, I have not tried this, so I don't know what would 
happen.

Frequently, I will give more/longer wash cycles than JOBO recommends based 
on observing residual bleach/fix still in the emulsion.  I use the 
stabilizer at a lower temperature (typically 24C) so during the wash I will 
gradually lower the temperature by changing the water with progressively 
cooler water.  I never exceed more than a 5 degree F drop at a time.

If you are using the Expert drum and change the temperature more that 10-15 
degrees F, the emulsion will shrink and curl inwards.  The film can then 
become lose from the ribs and make contact with the second sheet (this only 
applies to 4x5 film in the 3010 drum.)

So the quick answer to your question is no, but keep all factors in mind.

Regards, Pete

_________________________________________________________________
Chat with friends online, try MSN Messenger: http://messenger.msn.com