jobo cpp-2, 3010 expert drum with 4 sheets.
250ml fresh chemistry
While I've had some sheets stick when processing b+w in pyro, I've been able to cure it with a re-fix. I tried it with this and failed. I also tried re-bleaching it for a 2 minutes. At what stage is this happening?
Also, while my led readout says 38 degrees and the top drum area also reads 38 with a separate thermometer, the bottles and graduates only get to about 37.3 or so. Is it a pump circulation problem or what?
So the chemicals aren't getting to the base side of the film in that area on 3 or four of 12 sheets I did in two batches. It must have something to do with the way they're loaded. They should be locked between the raised ridges in the tube, right? Any tricks to keep this from happening again?
Note this was speed 4 on the dial.
Vinny, although I can't help you with the Expert drums (don't have any), I did some research recently before plunging into E6 developing using my Jobo CPA2.Originally Posted by vinny
Some more experienced colleagues said that they have the temperature of the water bath up to 39 degrees, in order to have the chemicals at 38 degrees when reaching film in the tank... The reason being that, if you're developing in a room/darkroom in which the ambient temperature is less than 38 deg. (as it usually is - around 20-22 deg., right?), the chemicals are getting a bit cooler when poured through the lift. Not much, but still... Makes sense, doesn't it? Lift is a bit cooler than the rest of the processor, since it's not heated.
So, for my processing and my drums, I settled at some 38.6 - 39 degrees for the water bath in the processor. With my processor (CPA2), the temperature control isn't very precise: when I set it to e.g. 38 degrees, it drops to almost 37.4 before the heater kicks in. When it does, the temperature in the water bath again reaches some 38.5-38.6 before it turns off. It also depends on the ambient temperature. Like I said, in my darkroom it's usually around 20 degrees C. So, with such temperature control, it's actually impossible to keep the temperature in the water bath at a steady 38 degrees. It's always fluctuating a bit - actually more than recommended +/-0.3 degrees (more like a full degree Celsius).
However, the results I'm getting are quite OK, so I learned to live with it. I just set the temperature a bit higher, never letting it drop below 38 degrees. Combined with the fact that the ambient temperature is around 20 degrees, and that nine tenths of the drum are exposed (wet) to the ambient temperature, which actually cools it a bit, I guess the temperature INSIDE the drum is about right
So, regarding your question about the pump circulation, I'd say that it's normal. The tops of the bottles and graduates are sticking out of the processor and the water bath, being exposed to ambient temperature, so it's actually normal that the temperature inside them could be a fraction of a degree lower than in the water bath - it especially goes for graduates, which are open at the top.
You should find a compromise which suits you and stick with that. After two or three runs, you'll be able to achieve your "standard" procedure. To put it simply, I'd recommend having the water bath at about 38.4 for starters.
thanks Denis. The water bath in the bottle area doesn't get up to 38 degrees though either. I did crank up the temp to get the temps right. The film came out fine except for the issue in the above pic.
Are the tubes in the 3010 straight ? Looks like something is making contact
with the film in the tube.
I load the tubes with the emulsion facing the center of the drum and just slide
the film in, if you're 'locking' the film into the ridges then you're loading it wrong
there should be a hairline gap between the tube wall and the film base.
The film is really held between the ridges and never touches the back unless the film is off size.
Put a level on the drum and make it right.
Use sufficient chemistry and pour it in fast with the drum spinning full speed, let it remain full for 3 rorations and then turn it down..
You will get better color with 6 step rather than 3 step. Nobody knows how to make a blix that is 100% effective. You get brighter colors and more contrast. Holds for C41 also.
You also want full washes where required so chems are not contaminated. Contamination is the big mode for failure. Wash the containers and use them one shot.
I'm using the kodak 6 step kit. There is a little play in the tubes when loaded but some of the film I'm using, old polaroid single sheet packet film is slightly larger but those sheets came out fine. Could the 3010 tubes be out of whack?
Are you pushing the film all the way to the bottom of the tube when you insert it?
I had a similar problem that to me looks like the chemicals are not getting to the back of the film. When I called the JOBO folks (years ago when they were in MI) they said this can happen if the film is too close to the bottom and recommended not pushing it tight to the bottom. Their other suggestions of making sure it is level and using enough chemistry have already been made.
I'll try not pushing the film to the bottom. I haven't paid much attention to it to notice one way or another. The machine and drum are level.
I am not sure what causes it, I do think the theories are interesting however. "It" is the anti halation backing not properly washing off.
There two ways to address it. First if doing B&W use a five minute prewash aka per the Jobo article in the Jobo Quarterly.
No pre wash for color films, but a 5 minute warm up.
Second way that I can attest works is tip the drum up every 1/2 second for 1 second. Doing this for every step multiple times, I then return the to drum operational position after each tip. I turn the drum motor off and on as I do this primarily because I don't like the idea of dropping the stationary gears back onto the spinning motor cog. I've heard people say this will chip the teeth.
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