Jobo 3005 and uneven development in smooth skies

Jordan.K

Member
Joined
Oct 16, 2006
Messages
261
Format
4x5 Format
Alright so a few months back after a while of using a beseler motor base to spin my jobo 3005, I acquired a cpp2 processor with a CPE arm. Everything seemed to working really well, except for in some negs with smooth skies I get dark blotches in my prints....... this would mean uneven development to me. I make sure the unit is level, so it I assume it is not due to that. I have been using JOBO's recommended chemistry amounts though so as not to stress the motor in the processor..... their amounts seem really low. Anyhow, if anyone has any suggestions please let me know. Could it be the CPE2 arm maybe? Some people say it is the exact same arm as the others. Or is it too little chemistry? Is my dilution too dilute? Arghhhhh.........
Tri-X 8x10
at least a five minute presoak
hc110 directly from the bottle: 1 ounce of syrup to 74 ounces of water
1100 ml of developer in the drum for 9 minutes
1 1/2 minute stop
5 minute fix
water wash
5 minute permawash
35 minute wash in gravity works film washer
 

Seabird

Member
Joined
Jun 13, 2008
Messages
112
Location
Sydney, Aust
Format
4x5 Format
Jordke said:
except for in some negs with smooth skies I get dark blotches in my prints.......
Click to expand...

You refer to "prints". Is this after enlarging the negs? And if so, are you sure the problem is not dirty condensers etc? Are the corresponding light blotches visible on the negs? (Just eliminating possibilities).

Cheers
 

snallan

Member
Joined
Sep 28, 2007
Messages
518
Location
Cambridge, U
Format
Multi Format
Is the direction of rotation reversing every couple of turns? As phaedrus says, if the rotation is continuously in one direction you can get standing waves, causing uneven development.
 
OP
OP

Jordan.K

Member
Joined
Oct 16, 2006
Messages
261
Format
4x5 Format
I DO have the drum spinning in one continuous direction to mimmick the results I was getting with the Beseler motor base........... could that be the problem? If so, why with the CPA-2 processor and not with motor base?? Thanks for all your help and insight.
 

snallan

Member
Joined
Sep 28, 2007
Messages
518
Location
Cambridge, U
Format
Multi Format

Unfortunately I have only used the Jobo processors, so cannot really help WRT the Beseler.

One thought though. Does the Beseler motor base simply rotate the drum, or does it slightly lift one end or other of the drum occasionally?
 
Last edited by a moderator:

snallan

Member
Joined
Sep 28, 2007
Messages
518
Location
Cambridge, U
Format
Multi Format
I think it would probably be as well to try processing with the reversing rotation, I have never used the Expert drums, but have processed sheet film in 2509n spirals (4x5), and in print drums (5x7) without any problems.
 

Jim Noel

Member
Joined
Mar 6, 2005
Messages
2,261
Format
Large Format
The Beseler has one eccentric wheel which slightly rocks the drum. It is necessary to reverse direction in the Expert drums. However, since it is not clear if the spots are on the negative or the prints, I still wonder if dirty condensers are a part of the problem on prints.
 

Paul Jones

Member
Joined
May 13, 2008
Messages
13
Location
Fairfield Co
Format
Pinhole
Try using the reversing mode. Also, for what it's worth, I only process 4 sheets of 8x10 at a time. That is all I can do in one run and have enough dev. (1000ml) for that many sq. in. of film.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…