4x5 with JOBO 2509N reel - not quite happy :(
I developed my first 4x5 negs only a week ago, and was quite happy - I used Jobo 2523 tank, and a variant of "tacos" system - i.e. I just "fixed" the 2 negs to the inner wall - see my thread "My first time! (in 4x5)" in "LF cameras and accessories" forum:
That came out quite nice.
However, a couple of days ago I finally got the Jobo original 2509N reel (purchased new), and developed 4 negs mostly just to see how it will work out. No problems with loading even without the leader.
However, the development wasn't quite even. I got some streaks on the edges of the negatives. Attached are two examples, scaled down, but the streaks are still visible.
Another thing is that in the right-hand corners of the scans you can also see some kind of imperfection in development, like a kind of "wedge" in top and bottom right corners.
I'm attaching two scans to show what it's all about.
Just to make it clear, I used the 2509N reel "by the book" - i.e. I also attached 2 "flaps" properly, as per instructions, with the "4x5" inscription facing outwards, i.e. with the tip of the "V" shape facing towards the center core.
The streaks could be due to uneven flow of developer - but the "flaps" are supposed to ensure evenness, right? What's this then?
The "wedges" in the right-hand corners might be due to negs touching those "catches" on the reel which prevent sheets slipping out... I guess.
Any ideas how to prevent this happening in the future? Or should I just forget the 2509N reel and use my DIY system as described in the previous thread?
Any suggestions appreciated!
Last edited by Denis P.; 10-04-2005 at 09:03 AM. Click to view previous post history.
Any uneven development I had with this reel (and CPE2 processor) disappeared when I standardised on processing at the high speed rotation.
Hmmmm - that might be the reason. I used the slower speed throughout....
Originally Posted by schambuk
I'll try higher speed next time.
Thanks for the advice!
Yup, you must use the high speed to avoid streaking. Later model processors come without a choice: high speed only.
Yes, there was an update by Jobo in the "Journal of Rotary Processing" that stated that they now require the higher speed rotation for all film processing.
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Hmmm, this is interesting info. I don't have a machine - just the tank and reel kit. I roll the tank around on the floor or back and forth onthe counter top. Haven't had any problems -yet. Dumb luck I guess. Thanks for the info.
I have had similar, actually quite a bit worse, problems with my jobo drums and reels. Mine have the same types of streaks at the top and bottom, but they also have really bad semicircular marks, about an inch in diameter, on the edges some of the sheets.
I attributed it to using a unicolor base that happens to turn directions almost exactly at one rotation. I have a different base that I just came across, and it allows for constant rotation so that I can run it for maybe 30 sec and then change direction. I am hoping that it helps. As for speed, I am not sure how it compares to the Jobo processor.
On other thing...is it normal to orient the film toward the inside of the reel? That is what I have been doing, because it just feels right, but I don't know.
Yes. Thats what the Jobo instruction booklette says to do. Emulsion side toward the center.
Originally Posted by Paul Sorensen
I've got two unicolors and neither causes a problem. Jobo used to recommend motorbases that reversed direction instead of unidirectonal bases.