ROTARY DEVELOPMENT: Uneven development : Xtol 1:1 / Jobo 3010 ???

[Keith Tapscott.]

I have been facing this problem for quite some time. I can't seem to figure out why this is happening. Any suggestions? It seems random and the pattern is always the same. Below are two scans of two separate negatives developed on two separate runs showing the problem. I have increased the contrast in PS to make the problem more evident.


Things I have tried to eliminate this

-Levelled the drum on the rotary base making sure there is no wobble as it spins
-Used fresh stocks of Xtol

-Pured dev on opposite compartments of the jobo 3010 in reference to film
-increased frequency of changes in drum development spin direction

My dev is
(done on cibachrome motor base)

I don't know much about the Cibachrome motor-bases, but I have found that using a rotation speed that is too slow on my CPA2 will cause uneven processing as does not using enough processing volumes of developer. Omitting the pre-rinse as already suggested may also help.

[Eric Biggerstaff]

I have developed thousands of sheets of film (both 4X5 and 5X7) in a 3010 with all sorts of film (including Acros) and many different developers (including Xtol) and have generally had very reliable results and even development. The times there were issues they were caused by me - not the drum, film or developer. And I use a Beseler base that does not change directions (and I don't change them when I am developing, I am lazy). Also, I always use 5 minute pre soak in the drum with it rotating. Lastly, I use 750ml of developer per run.

The drum needs to be rotating whenever chemicals are entered into the system. I use a large funnel with a hose that I purchased from an auto parts store. The uneven lines look almost like surge marks from developer not being evenly entered into the system.

Good luck and I hope it works out for you, I am sure with a little time and testing you will figure it out.

[ic-racer]

Those negatives show up positive on my screen. When I invert them it looks like there is not enough developer in the drum. I can't find any reference to the volume of developer in the tank. I get even results with 470ml of T-max developer in a 3010 and no presoak.

[Bruce Watson]

OK, there's your problem. The streaks are from the developer not initially being distributed correctly as it flows on the film.

Yep. That's exactly what causes this kind of streaking. Glad somebody finally said it. So...

1) drop the prewash
2) don't use development times below 5 minutes
3) use the development workflow that Brian suggests

Should see your problems gone.

As an aside, it looks as if your exposure might be too high, which might account for your density at this (very) short development time. But without some densitometer readings I'm just guessing.

[timparkin]

1) drop the prewash

What problem is the pre-wash causing?

[timparkin]

Part of the reason for that is Kodak doesn't recommend a prewash anymore, particularly with Xtol. In some instructions, it states a prewash requires a 10% longer development time to counter the diluting that occurs from water left in the tank after a prewash.

What's wrong with 10% extra development time? Kodak perhaps say not to use a pre-wash to get around problems with variable wetting amounts and potential for water ph to affect the final development times. I can't see how it could affect the rate of development across the film, only help it.

Tim

[timparkin]

There is nothing wrong with using a prewet or increasing the published times by 10% to compensate for a prewash. I am merely stating that is what Kodak says in their publications. They no longer include a prewet in the instructions, and state if one is used, then compensate your time for the reduced contrast that will happen. I am guessing the extra time is needed either from a slight dilution from any remaining water, or more likely, extra time needed to displace the water in the gelatin emulsion from the prewet. Because they do not include it in their instructions, their recommended development times are based on not using one.

Ah OK - so really there is no reason not to do the pre-wash. I can understand that some people manage without but from my experience it has solved issues of uneven development *because* it slows down penetration of developer, hence allowing time for the developer to distribute itself around the tank.

Tim

[Erik Larsen]

It's quite simple to rig up a way to pour the solution in on a roller base while it is spinning. It might help with your problems. Here's a pic of a simple wood stand to hold my funnel and 3005 drum. Made with spare wood laying around in the shed and a coat of poly urethane.
erik

[Greg Blank]

Erik;
Glad to see you are making good use of that and getting good results

It's quite simple to rig up a way to pour the solution in on a roller base while it is spinning. It might help with your problems. Here's a pic of a simple wood stand to hold my funnel and 3005 drum. Made with spare wood laying around in the shed and a coat of poly urethane.
erik

[Erik Larsen]

Erik;
Glad to see you are making good use of that and getting good results

Works like a charm, I'm quite happy with the hundreds of sheets I've put through it so far.