Aristo VCL4500 Printing Fluxuationsgreenspun.com : LUSENET : Large format photography : One Thread
I recently (this week)started experiencing printing fluxuation times with my aristo head. I'm not doing batch printing but the usual expose, develop, stop, fix and bath. There is at least 4 minutes between exposures. Each sucessive print is lighter than the previous. The contrast seems to be the same but it is hard to tell. Has anyone had this experience before. It sure is frustrating (and expensive).
-- Gary Brennan (firstname.lastname@example.org), December 27, 2000
This may sound too simple, but are you using a Metrolux or Zone VI timer?
I use a Metrolux and it measures the total light the print receives and turns the head off when it reaches the pre set amount of light (lux).
If you are using a standard timer, fluctuation in line voltage, warmup and cool down could have a significant effect.
-- Mike Kravit (email@example.com), December 27, 2000.
I suggest you contact Aristo. Since this is a new phenomenon for you they might be able to tell you the cause.
As a general comment, I see lots of postings where it seems people are reluctant to contact the manufacturer. Most manufacturer's are happy to provide information on their products (they'd be crazy not to) and can often diagnose problems.
-- Charlie Strack (firstname.lastname@example.org), December 27, 2000.
There is a remote possibility that it is not your light source. It could be your developer temperature. I use a bathroom darkroom. While the room is warm, the base of the tub is cool. If the water bath envelope is not monitored, my chemistry will cool off by 7-10 degrees over a 1 hr period. My blacks lighten because of the reduced development. You should probably check this variable also. Maybe this helps. My understanding is that cold light heads are very stable after they are warmed up.
-- Joseph Wasko (email@example.com), December 27, 2000.
Gary: I suspect the problem is with the cold light. I also have an Aristo light source and have had a similar problem. My solution was to plug in the heater cord, which had come unplugged. You might have a similar problem with your head. The heater may not be working. There will sometimes be slight variations with a cold light head without a compensating timer. When there is a delay between prints, I turn my light on for about 15 seconds, turn it off and insert the paper in the easel. The temperature needs to be pretty constant with cold light.
-- Doug Paramore (firstname.lastname@example.org), December 27, 2000.