Dev issues Jobo 2521/2509N

[joekennedy]

Hello all,
I need some info please on an issue I'm getting and as a regular lurker / reader here picking up valuable info from many of you, I hope you can help.
All pictures are from my recent buy of a Mark VII MPP Microtechnical, and all on Delta 100 dev'd with Rodinal 1:50 @ 14 mins / 20 degrees. I picked up the Jobo 2521 / 2509N for the 5x4 and have been using this by inversion.
The first image is shot with the 180mm Schneider Xenar that was with the camera. Although I messed up with the qty of dev - 1L when the tub says 1.5L - the negs have come out dark but ok.



These next two images have been shot with a Super Komura SW 90mm f6.3 on a home made lensboard that I have checked to ensure it is lightproof.
I used the 1.5L of Rodinal and developed as normal - inverting 6 or so times slowly for 10s every minute and gently tapping down after to remove any bubbles. Having only 1L of stop and fix, I put the 2521 on a towel on the counter and rolled it to ensure coverage.
There are spots, blemishes and a strange fogging on the negs - what has caused this?
I am thinking its just a case of developer but I've never had anything like this so could it be also my home made lens panel - I made it from two sections of 3mm solid foam PVC board, one piece cut at 86mm square and placed centrally in the other at 101mm to create the step. I painted it flat black and have shone a torch through the bellows both ways to check if lightproof - it is.
The Super Komura is also a monster of a lens - I have to screw in the rear element through the bellows as its egg timer style wont fit through the front standard. Also I am not using a cone type lens board as my DIY skills wouldnt stretch to that. Could it be a number of these or is it just a case of a dev mystery and nothing more?
Any help greatly appreciated.

[Chauncey Walden]

Do you presoak?

[joekennedy]

No - could that be why the dev seems to have made all those marks?

[Chauncey Walden]

I think that is part of the problem. You also have a light leak in your first DDS at the slot end. You are loading your film correctly in the 2509N? Emulsion side in? Are you loading more than 4 sheets at a time?

[Bjorn Nilsson]

Let's see. Did you develop the first shot in a different run from the other two shots? At least it sounds like that from your post above.
If so, I would guess that you forgot to use the center post when you put the tank together for that second run. Apart from making the chemicals going to fill from the bottom, more importantly it makes the tank light proof when filling/draining the tank with the chemicals along the process. That is why you get these severe light damages.
Now I could be wrong, but it's quite easy to forget that center post if you use a "single" tank (i.e. the about 5" high tank). After fumbling and messing with getting the films loaded correctly, which sometimes rises the pulse a bit, it's easy to take a bigh sigh of relief when all the films are in place and just put the lid on top.
Also, the pattern of the light damage seems to correspond to the way the film spiral is built. I took a very crappy picture with my mobile phone, but I recon it will prove my point.

By the way Chauncey W., I have processed quite a lot of sheets with the 2509N and have had no problem so far when loading 6 sheets of film in them. I did have a mishap once with a CombiPlan back in the -80'ies, so I've learnt to take my time loading the film onto the holder/spiral.

Another tip along the way: I built a roller base from a piece of hardboard and 4 cheap furniture wheels. Takes 8 small screws and a few minutes to put together. Total cost of maybe $4-5 or so. The Jobo drums are intended for rolling use, which will also save you a lot of chemistry (even though Rodinal at 1:50 is quite cheap). When used in rotary fashion, the minimum amount of soup is 270ml. (But you can of course use more.) Make a search for a "Jobo rotary base" and you will eventually find pictures of an adjustable one. I take it you can figure it out from there.
The way a single tank is built, it will almost tip over if put on a roller base. But a thick rubber band at the very base will stop it from sliding away on that end. If you put the whole device in a sink, just put the lid end towards the wall of the sink and you're safe. Or, put something like a filled bottle to stop the lid end if you use a tabletop.
(To confess, I've later on got me a CPA2 as I found one at the right price and I wanted to use Expert drums, but that's another story.)

//Björn

[joekennedy]

Thanks for all that.
I think its a combination of all the above - I'm not sure which way the film was loaded into the 2509N, I'll check next time to make sure its the correct way in. I'll also presoak at 20 degrees - for how long approx?

I didnt put in the centre post so I guess that's also a major part of the problem - I use a Paterson for all my 120 / 35mm so with only using the Jobo for the recent 5x4s I was hoping it was something simple.

I'll keep an eye on the DDS to see which are leaking light - thanks for that.
I'll also make up the board with the wheels - sounds like a good idea - do I have to keep it rotating for the full 14 mins or so?

Photography makes you feel like a golfer sometimes - the shots you know go well but as soon as you change what you are doing or how you do it, you're straight back at the beginning!

[Bjorn Nilsson]

I'm sorry about my crappy picture (I'm not that much into digital cameras... ), as it's very obvious if you put back the negatives in the spiral. The pattern of the damage should match "perfectly". But let me put it this way: If you use the center post, that horrible light damage in your second and third example will be history.

And don't worry, there are so many other mistakes to do along the way. This is why this forum is so great. The users makes up a more or less complete database of silly mistakes... and are willing to admit to them.

//Björn

[Chauncey Walden]

I thought maybe in loading 6 sheets the film might have gotten out of the track and touched another sheet or that the closeness might inhibit chemistry movement using inversion. They were really made to roll. And, I assume the 4x5 end plates were used to keep things in place and not slide into each other.

[venchka]

The longer Jobo tanks (2551/2553) and a motor roller base really are a lot easier and provide even delopment. And use a lot less chemistry. 14 minutes is a long time to agitate manually.