Light Leaks and Sprocket ghosting

[Johnj88]

I bought a first generation JOBO CPP2, and the temp control, water pump, and motor appear to be functioning perfectly well.

But some rolls I’ve developed for people have sprocket hole ghosting, and weird light leaks.

The only options I can think of are:
1) camera needs a CLA
2) changing box has a light leak
3) less likely something wrong with the JOBO?
4) rolls bought were actually bulk loaded and something went wrong in bulk loading?

examples here:
https://imgur.com/a/jdmnmKu
https://imgur.com/a/I4UocMs

I’ve emailed the JOBO guy as well tonight, waiting for a reply.

Anyone have insight?
There was some forum posting saying sprocket hole ghosting could be from too rigorous agitation, but I’m using the “P” setting on the CPP2 as the manual states to for 35 and 120.

Unless somethings wrong with the motor speed setting internally.

Any ideas are welcome and appreciated

 

[fdonadio]

Because of the direction of rotation with a Jobo, I don’t think these problems are caused by the agitation.

Are the rolls that exhibit the problem all from the same person and camera? If not, I would tend to believe it’s a processing problem.

 

[AgX]

There is a kind of pattern in the artefact: Quite vertical banding, typically a narrow and a wide band.

 

[glbeas]

Does your tank have the proper stem the reels slide onto to create the light trap? This looks like fogging from a light leak into the tank.

 

[Johnj88]

Same person, I asked him if it’s from the same camera. Still awaiting answers

yes, I made sure to put the right stems in the tanks and fully load the reels.

i thought the JOBO tanks were fully connected, but the banding pattern is interesting. Maybe the tanks weren’t fully sealed together.

 

[Johnj88]

The vertical, rectangular banding seems to mimic the internal sprocket marks that connect JOBO tanks, such as the 1502 and 1503 that I used.

Since they were new, they were also pretty stiff. I hope it wasn't the case that I didn't connect the tanks fully, leading to light leaks that made that rectangular banding pattern, but the more I think about it, the more that might explain a lot of the leaks.

I thought I triple checked how secure the tanks were attached to each other prior to loading the film, but the connectors seem to require a bit of rough handling, and do not click together easily. Maybe I just didn't connect them as well as I thought.

If there are any other JOBO users that may have done the same error, I was hoping they would chime in to see if similar banding has happened from not perfectly sealed extension tank to regular tank.

Will shoot a test roll tomorrow and dev similarly.

 

[Johnj88]

Sigh, of course Omer from cat labs has all the answers.

Unfortunately, I think it’s an error from my end.

He gave me a good tip to test connections between tanks by blowing in the motor at the top, and seeing if any air leaks out. It should be a tight seal.

now that I know if tanks are properly secure 100%, I’ll do a test roll tomorrow. I have a feeling there won’t be a problem

 

[koraks]

If there are any other JOBO users that may have done the same error

I have, but don't recall what kind of fogging I got. But I can confirm that especially new tanks can give some trouble fitting the lid on. I always double check by testing if the lid will rotate once it's been fitted onto the tank. If it does, it's not seated properly.