Weird mottled look on negatives - what went wrong?

As has been mentioned, this looks like not enough developer in the tank. Those are bubbles appearing on your film. You said it only happened on one roll, along the edge of the whole roll (right?); as you guessed, I think this roll as at the top with the affected side up. Check it by measuring out some water in exactly the same volume you used developer, and add it to your tank with reels in and the lid off, and take a look. If your reels aren't completely covered with at least a few millimeters of liquid to spare above the top, you don't have enough solution in the tank. Even if it looks like it will just cover, the agitation can form bubbles at the top of the solution, and voila.

I just did a search on recommendations for volume of solution to cover two rolls in a Paterson tank and found several references to problems with bubbles when using only the recommended 600ml of solution. Several folks suggested going with moderately to significantly more solution in the tank and that clearing up the problem. (Per threads on photo.net and APUG) Hope that helps.
 
drewbarb said:
As has been mentioned, this looks like not enough developer in the tank. Those are bubbles appearing on your film. You said it only happened on one roll, along the edge of the whole roll (right?); as you guessed, I think this roll as at the top with the affected side up. Check it by measuring out some water in exactly the same volume you used developer, and add it to your tank with reels in and the lid off, and take a look. If your reels aren't completely covered with at least a few millimeters of liquid to spare above the top, you don't have enough solution in the tank. Even if it looks like it will just cover, the agitation can form bubbles at the top of the solution, and voila.

I just did a search on recommendations for volume of solution to cover two rolls in a Paterson tank and found several references to problems with bubbles when using only the recommended 600ml of solution. Several folks suggested going with moderately to significantly more solution in the tank and that clearing up the problem. (Per threads on photo.net and APUG) Hope that helps.
Click to expand...

Okay that sounds pretty darn helpful. I always assumed I was already over filling a touch with 600ml (290ml per reel is recommended after all) but maybe Ill increase. THAT SAID ive had many more successful attempts than unsuccessful with this volume, and for it to affect so much of the negative - it still doesnt ring true. Regardless I think Ill have to put it down to a fluke - until it happens again! But for sure im going to test how much volume i can get in the tank - it will help to visualise it.
 
I have that sometimes, too, although not to the extent you observe it, and attribute it to foaming of the developer.

I think overfilling the tank as you do makes it worse because you don't leave space for the bubbles to burst and the air to rise to the top of the tank.
 
I say foam.

Rodinal is a caustic and like soap does this thing with surface tension.

I use Diafine in a 2 liter tank and got the same looking bubbly effect after my developer got seasoned. Diafine gets reused and tends to thicken with use, this is when the problem started. The solution for me was to use an empty reel on the top of the tank.

Always happened on the top reel. In my case I only can develop 7 rolls of 135 in my 2 liter tank because I use one reel as a spacer on the top.

Cal
 
It's obviously not a development problem since one film is correct, but not the other.

In my opinion the problem is aerial condensation due to temperature. If you wear your camera on a bag while the air is (very) cold, the sigle fact to take it suddenly in your (hot) hand create condensation.
 
olliewtf said:
Okay that sounds pretty darn helpful. I always assumed I was already over filling a touch with 600ml (290ml per reel is recommended after all) but maybe Ill increase. THAT SAID ive had many more successful attempts than unsuccessful with this volume, and for it to affect so much of the negative - it still doesnt ring true. Regardless I think Ill have to put it down to a fluke - until it happens again! But for sure im going to test how much volume i can get in the tank - it will help to visualise it.
Click to expand...

Also, you should check if the spirals can move on the central column when the tank is inverted (You can use a rubber band as stop). If they move upward during development, it will seem as if there is not enough liquid in the tank.
 
SyPat said:
It's obviously not a development problem since one film is correct, but not the other.
Click to expand...

Quite the contrary.

If you don't have enough solution in a multi reel tank to cover both reels, the upper one(s) are not completely immersed in solution and will show areas of underdevelopment just like the ones shown in the picture by the OP, while the lower one(s) will turn out perfectly fine.
 
What are the recommendations per film for your tank?
Unless you fill a bit more than the recommended amount for your tank, it may be the case that you have too little liquid in there.

My tank, which can take 2 35mm reels or one 120 reel, says 500ml for two 35mm films, I then use 600ml.

I wrongly assumed you did the same.

Check the underside of your tank, it should have some metrics there, as a guide for the amount of liquid needed.
 
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