Question about partially stained Tri-X and Rodinal 1:50

[john bode]

My last couple of rolls of Tri-X in Rodinal 1:50 have come out underdeveloped with a brownish stain on

the first 10 frames or so. Based on what I've found in the archives, the problem is insufficient agitation (I

did 3-5 inversions once a minute, instead of every 30 seconds). I've been so paranoid about grain and

contrast that I've gone too far the other direction.

 

I understand that. What I don't understand is why the stain only appears on the front half of the roll.

That's the half that's on the inner part of the reel, and the stain is apparent as soon as I pull it out of the

tank, so it's not a matter of crud dripping down as it's hanging to dry. The roll is uniformly

underdeveloped, but not uniformly stained. Does the center part of the tank not respond to agitation the

same way the outer part does? This is a stainless steel tank and reel.

[ronald_moravec1]

If all you changed was inversion cycles, that most likely is the problem. Be sure to rotate the tank as you invert or rotate it when you set it down. Filling the tank with more than enough developer to cover the film will inhibit agitation. One of the best ways to get the best agitation in a stainless steel tank is to use a two reel tank with the loaded reel on the bottom and an empty spacer on the top. When inverting, the film then is fully free of developer contact. Sheet film is agitated this way. Two inversion are sufficient.

 

I would also look for a contamination problem from previous developing sessions. Mix the rodinal well water and the best practice is to drop the loaded reel into a tank already full of developer, stainless steel only again. Plastic tanks are different.

 

Yes the center can get less agitation than the outside, but you really can not over agitate the outside unless you set up some uniform pattern that is detrimental. That is why I rotate the tank.

[chris_waller]

This doesn't sound like a developer problem to me. I use Rodinal exclusively, and have done for twenty-odd years. Rodinal is noted as a clean-working developer and i have never encountered any staining in all that time. This sounds to me more like a fixing problem. The fact that it occurs only on the inner part of the reel, where the movement of the liquid is less, reinforces my suspicions. Could your fixer be near exhaustion?

[william john smith]

I have to agree with Chris on this one. I have been using Rodinal for over 30 years and never

have seen any staining problems. As far as agitation goes, I have been following the

instruction sheet all this years and what do you know, the scientists at Rodinal do know what

they are talking about!<BR>I would mix all fresh chemicals and do as Rodinal suggests and I

will bet that the problem disappears.

[john bode]

Chris,

 

It's possible that the fixer may be nearing exhaustion, but it still clears a snippet of the leader in about 2 minutes, so I thought it was still okay. I will mix a fresh batch and see what happens.

 

Thanks.

[pete_andrews10]

There's far too much mumbo-jumbo talked about agitation, and really it's very simple. It's inverting the tank that does the agitation, as long as there's some air to bubble past the film.

 

Rotating the tank is a very inefficient way of mixing used and fresh developer, which is why inversion agitation tanks superceded all the old "twiddle stick" type tanks. I've never deliberately rotated an inversion tank, and never had any problem with uneven development either.

 

Also, the difference between inverting once a minute and twice a minute is minimal, provided the developing time is reasonably long.

 

A brown stain with Rodinal would indicate to me that the film was allowed to sit in contact with air, after it had been wetted with developer. If this had been rotary development, I'd have said that the tank didn't have enough developer in it.

 

Could you have left the film standing after emptying the developer out and before pouring in the fixer, John? Perhaps after an insufficient rinse?

[john bode]

I didn't leave the film standing for more than a couple of seconds between each bath. I'm also doing full inversions on the tank, and rotating it a quarter-turn when I set it back down.

 

If it helps, the stain appears towards the middle of the film, not at either edge (the edges are relatively clear).

 

It could be that I'm overfilling the tank, and there isn't enough air to allow sufficient agitation (I measure out 8 oz, which is what I thought the tank used).

 

I'll have to play with it. Unfortunately, I'm on business trip at the moment and won't be able to do anything before the weekend.

[bob_the_builder1]

In my experience brown staining has always meant insufficient fixing or weak fixer - try it

with a fresh batch and fix for 5 mins.

[ronald_wills]

John, I think Bob may be right on this. This kind of problem seems to come up quite often here. Try refixing and washing your "stained" negatives. Always fix for twice the time your negatives take to clear. Hope it works for you and let us know.

[big toys are better]

The fixer proponents are correct-- Rodinal diluted at 1:50 or greater doesn't really need any agitation after the first minute unless you wish to increase contrast, and if you are trying to reduce it, then dilute more and reduce agitation to once very few minutes. I don't even think a prewash with TX would be helpful, and the staining is rather indicative of a fixing/washing issue. IF you are using a large tank and reels, try adding an empty reel at the bottom and then your loaded reels, plus empty ones above, all to increase turbulence and mixing when inverting the tank, and the latter to prevent the loaded reel from leaving the soup.

 

BTW, Rodinal is NOT the best choice for 400 class films, especially if grain is an issue, better to use a sulfited developer like D-76 or XTOL at a modest one-shot dilution if sharpness plus finer grain is desired....

[john bode]

The fixer proponents were indeed correct. Mixed up a fresh batch this morning and

processed another roll, and no staining is visible.

 

Thanks.