4x5 edges less development with Jobo CPA2 and 3010 drum

**Bruce Watson** · 27-Apr-2010, 20:36

Does it *always* happen, every single sheet? If not, does it happen to every single sheet in a run? If not, it's not the process.

I've had a line of increased density show up on the negative when working in bright conditions -- the film holder's film hold-down rail itself was quite shiny and reflected some additional light onto the edge of the sheet. Perfectly straight line, almost exactly matching in width, the depth of the face of the hold-down rail (which is 90 degrees to the surface of the film). The "fix" was some fine sandpaper to take the sheen off that surface. Poof! Problem went away.

If it's really a line of *less* density on the negative... IDK.

**Andre Noble** · 28-Apr-2010, 07:32

I would guess he uses the gravity works for washing as the Jobo is not archival wash - this per museums. I had one, could never use it because the Los Angeles tap water is incredibly hard, and ruins films.

As for rotation speed, one should always use the very slowest rotation speed as possible to develope film in the Jobo. I bet a too fast rotating drum is the cause of the lines.

**Jordan** · 28-Apr-2010, 07:52

So like I said it is actually a light line in the negative thus causing a darker line in the print. I am really confused and am gonna process a test batch today on speed 4.

**Andre Noble** · 29-Apr-2010, 18:10

At a high speed rotation the ridges in the 3010 would cause uneven development problems that you probably won't encounter at high speeds with the 3006 drum.

I really do not know why you want any speed other than the very slowest roatation speed when processing sheet film in the 3010 in light of these ridges.

**Jordan** · 4-May-2010, 18:32

Ok so after processing another batch and doing in camera tests, I am lead to think that maybe in my haste I did put a few new negatives base-side inward in the jobo by accident. Someone earlier in the thread suggested this and I think they may be onto something. Do any of you really think it would be possible to have an otherwise perfect negative minus this line of less negative density by making such a mistake? Let me know and as always thank you all for all your help.

**Greg Blank** · 5-May-2010, 15:50

That drove you crazy, I remember your call...even I couldn't figure that one out

Originally Posted by Bruce Watson

Does it *always* happen, every single sheet? If not, does it happen to every single sheet in a run? If not, it's not the process.

I've had a line of increased density show up on the negative when working in bright conditions -- the film holder's film hold-down rail itself was quite shiny and reflected some additional light onto the edge of the sheet. Perfectly straight line, almost exactly matching in width, the depth of the face of the hold-down rail (which is 90 degrees to the surface of the film). The "fix" was some fine sandpaper to take the sheen off that surface. Poof! Problem went away.

If it's really a line of *less* density on the negative... IDK.

**eman** · 8-May-2010, 13:17

Andre, could you expand upon the lack of "archivalness" in the Jobo processor that you mention? Although I do many more washes, I was told by a Kodak professional helpline person I could get by with 4 rinses after hypo clearing! I still don't believe them on that one.

Thanks
Eric

Originally Posted by Andre Noble

I would guess he uses the gravity works for washing as the Jobo is not archival wash - this per museums. I had one, could never use it because the Los Angeles tap water is incredibly hard, and ruins films.

As for rotation speed, one should always use the very slowest rotation speed as possible to develope film in the Jobo. I bet a too fast rotating drum is the cause of the lines.

**Michael Szedon** · 8-May-2010, 20:58

Sounds to me like the edges of the film are getting more developed than the middle. This happened to me when developing cut film using hangers and a tank...that's why I tray develop my cut film now, problem gone.

**Ed Richards** · 9-May-2010, 07:01

> I would guess he uses the gravity works for washing as the Jobo is not archival wash - this per museums.

I think the museums are thinking about paper. Film, esp. modern film like Tmax, is really easy to wash. The backing is impervious and absorbs nothing, and the emulsion is so thin that the diffusion time has got to be seconds or less for stuff to get out. Three changes, the first two filtered and the last distilled should be more than enough, as long as you drain the tank completely between washes. No reason to use Hypo clear.