Dark circles on the edge of negative

[disco2000]

Hello
I just developed a roll of Acros in d76 today, and found these dark, circular circles along one edge of my negatives. I've had these before, I'm guessing it's a developing issue, but what could be the exact cause of this be? Seems like those spots are being underdeveloped?
You can see they're all along the right side of this image.

[oftheherd]

What was your development method? Is there a chance you didn't have sufficient developer in your tank, if you were using a tank?

[jmcd]

What format? It could also be a problem with so much developer that it does not allow for enough movement to get fresh developer everywhere. I just cover the reels.

When I have had too much developer, I have had a band of under-development. And I have had sprocket spaced surge marks. But never circles.

Maybe it would be helpful to know everything: format, reel type, tank, etc.

[disco2000]

It was a single 120 roll in a patterson tank. I used 500ml of developer vs the usual 600ml that I use, although I've had similar marks with 600ml before.
D76 1+1 10.5 minutes, agitated every minute.

[rajivk]

I suspect these are due to air bubbles. I had a similar problem and it took a while (and another 10 rolls) for me to figure out what was causing it. Check out the following links:

http://www.flickr.com/groups/diybw/d...7623856440057/

http://www.apug.org/forums/forum37/5...ervations.html

I just could not get rid of the air bubbles (something about the water here I guess) till I started using a couple of drops of Edwal LFN wetting agent along with the developer for 1 roll of 120 film. Problem solved .

Hope this helps.

Rajiv.

[ItsReallyDarren]

Was this inversion agitation or twirl stick agitation?

[Roger Hicks]

Another vote for air bubbles. Bang the tank hard on the table a couple of times before you start agitation.

Cheers,

R.

[tj01]

Or tilt tank sideways and pour, leave room for air to exit.

[disco2000]

I was inverting the tank. Air bubbles sounds right.. I do tap the tank, but I guess I need to be more vigorous. I wonder why it doesn't happen for 35mm though.

Thanks for the help everyone!

[tlitody]

Agreed its bubbles. The spool slides up the core and doesn't go all the way back again if you don't tap it hard enough. With two spools and 600ml I think they are covered because there isn't room for them to slide up.

[Ronald M]

Put something on the core so the reel does not slide. Rubber band? Spring?

No need to tip a Patterson tank while filling. Developer goes down center funnel and fill bottom up very nicely which is exactly what you want. A perfect system.

First agitation is supposed to be with stick immediately after developer goes in. ALL others are to be inversion only.

[Pherdinand]

could be foam as well. Yea ok, foam is about the same as air bubbles (but not exactly)

[LeicaFoReVer]

why dont you put a little more developer so that even if you have the bubbles they will not reach down to the film border...