[LargeFormat] New Jobo in house

[Frank Filippone]

There are 3 different types of 4x5 reels....

The oldest:  grey core... will NOT fit the 2500 tank core.
Second:  Clear one side,  and black the other side  2509
Third:  Ditto #2 but has little "bumps" at the entrance of the outermost
film entry points.  This holds the film retainers onto the reels.  2509N

You want the third type, or at worst the second.

make sure the reels are really dry before trying to reload... otherwise you
will be unsuccesful in loading... I use spare reels as the "second" run in a
short period of time.........
you can try 6 sheets per run, but some data has it that only 4 sheets will
be the max to make sure of even development. I only have used 4 sheets, so
can not make comment.
Presoak for 1 minute.... depending on yourdeveloper... read JOBO instruction
on line for more details....
Set the temp to some temp you are happy with. as measured by a
thermometer... after a very lengthy warm up.. overnight?  Then mark the
location of that temp on the dial.  I use 75 for everything,......  I do not
move the dial, and have been tempted to glue it in place!
600mL per solution MAX.  The motor is apparently not strong enough
otherwise......
I use water stop bath.... I got some pinholes ( my first ever) when using
acid stop.
Wash in the JOBO.... 20 changes of water with a 30 second wash per .....
If you decide to wash not in the JOBO, remember the chemistry is stil in the
infill lines of the JOBO... you MUST wash through the left over chemicals
before you start your next run......

Watch your exhaustion of developer... if something goes nuts compared to how
it was in your older methodology, then go back to this question....  Is
there enough developer concentrate to properly develop this film?  Some of
the number I have is 40mL of concentrate of TmaxRS is enough for 4 sheets of
4x5.

You DO need to rerun your calibrations... the JOBO method does not coincide
with a calibration constant of -12% from deep tank.... and I have found that
depending on how YOU like your negative density, YOUR time is substantially
different than MY time.  So don;t trust me or someone else's results, unless
you confirm them.

Welcome to the 21st century of film development.

Frank Filippone
red735i@earthlink.net