View Full Version : C-41 and Jobo

Robert Ley
26-Jun-2006, 10:22
I have been processing all my film in a Jobo CPA-2 with 2500 series tanks. Recently I have noticed some low density streaks on my 4x5 NPL processed in Fuji-Hunt c-41 chemistry. I use the 2509n reels in 2500 series tanks and always use the plastic end caps. I know what many will say that I should use the Expert drums that they are sooo much better. I have 5 of the 2509n reels and can't afford to replace them with expert drums, so please don't suggest that. I use the P setting for the C-41 and standard B&W developers and 3-4 with Pyrocat HD all with good results.
I am thinking that I may use a slower setting with the C-41. The streaking is not bad, but it is annoying and I have only noticed it in one negative that was very light in density. It is hard to see in the negative but you can notice it in the print. My question is has anyone else noticed this with the 2509n reels and what would be the effect of slowing the rotation speed. Thanks for any help the forum can give me with this vexing problem.

Larry Gebhardt
26-Jun-2006, 12:11
Try removing the middle sheet of film. In other words only process 4 sheets per reel. I think this minimized the density problems I had with this system, but I switched to the expert drum before I could be absolutely certain. I was seeing it on black and white film.

Larry Gebhardt
26-Jun-2006, 12:13
Also, I used the F speed for all my film.

ronald moravec
5-Jul-2006, 11:56
Turn up to highest speed for the first 60 sec. Use more chemicals.

Use as an inversion tank with the proper lid. Add the developer and drop the reels into the full tank in the dark. The first agitation will be to remove it and replace it inthe developer. Then add the lid and continue.

Pray the high speed works before you resort to the other ideas.

4x5 in the 3010 expert drum never screwed up a single neg for me.