Spots (pinholes?) on Acros 120 mm

[DrZ]

Hi,
I have been processing Acros 120 with Clayton F76+, Ilford stop bath and either Clayton Odorless Fixer or Ilford Rapid Fixer. Use Paterson tanks with plastic reels.
From time to time I have a roll with one or two frames with spots. Looking the negative under the microscope is not possible to observe halo (or edge effect) on the spot. In the print it shows as darker spot and very uniform.
This effect was observed in one roll of Acros 35 mm and none on Delta 3200 120 mm.
Below is a crop showing one third of the negative on the width (portrait mode). By enlargement and measuring the spots they seem to be on the range of 0.2 to 0.45 mm diameter.
I appreciate any help on resolving the spots.

Thanks in advance,
DRZ

 

[JohnArs]

Oh Ah its very easy this are the UFOs which are on the way to you;--)))

 

[fschifano]

I wonder if this is the same bunch that was reported to be over Washington, D.C. a week or so ago?

But seriously, this doesn't look like pinholes. Looks more like you accidentally contaminated the film with something. Is the emulsion blistered? You'd be able to tell a real pinhole by touch.

 

[DCV]

Hi Dr. Z
That same problem hit me with Kodak products years ago and I consulted with my favorite tech sales rep, Roger Meritt. We figured out that I was somewhat careless with the way I was diluted the stop bath (too strong) and that it was shocking the film and causing the same pinhole spots on the film. I followed dilution instructions more closely and they didn't come back. That's what happened to me. Hope it helps!

 

[John Simmons]

I had this exact same problem with this film. I switched films for about a year and came back to it and no more problems. I could never figure out what the issue was.

Regards,
John

 

[Sal Santamaura]

Those are air bells. I've tried Acros with and without a pre-rinse as well as pre-rinsing two times and could not overcome them in an inversion agitation scheme. This problem persisted even when I added a special scrap of wood to the sink that permits banging the tank really hard in an attempt to dislodge the bubbles; they appear on 35mm, 120 and 4x5 versions. With rotary agitation no such air bells / spots appear. Now the only Acros I use is 4x5 in a Jobo Expert drum.

I suspect Acros has a particularly active wetting agent based on the amount of foam present when opening the tank, even with a double pre-rinse. This problem has not occurred with Delta 100, my current primary 120 and 4x5 film. When developed in Perceptol 1:1 it's remarkably close to Acros in terms of grain and sharper too.

PS The film isn't "120mm." 120 is a type designation; actual width is 60mm.

 

[dpurdy]

I concur with Sal. Looks like airbells to me. I always presoak Acros and have never had that.

However now that I think of it, a few years ago several people here had that problem with a late batch of ilford 220 FP4. No longer made. Looked just like airbells or even foam marks and definitely from the factory that way.

 

[Jim Noel]

If they are air bells you might try one drop of LFN in the pre-soak which will help to get rid of the air bubbles. Also, is your pre-soak water coming out of the faucet significantly cooler than usual? If so, letting pre-soak sit until it reaches room temperature may help. I use a water only stop rinse to prevent sudden shrinkage of the film which causes pinholes.

 

[sbandone]

I have had a plague of small blisters or air bells or dust particles using Ilford FP4 and Delta 400, over a period of 18 months - to the extent that I almost decided to give it up traditional processing after 40 years. However after much reading and testing I have solved the problem for me anyway. here goes:

1. Using Jobo CPE system change from 1520 tanks to 2521s larger diameter with wider film grooves - easier loading and better distribution of chemistry
2. No prewet - I had used between 2-5 minutes
3. Either no stop bath or use 2% glacial acetic acid - I was using Ilfostop or Paterson Acustop. I think there was a reaction with the developer- originally Aculux 2, but also with ID 11 diluted 1:1
4. Use one shot chemistry throughout - avoids particulate accumulations
5. Dry using Ilfowet

It works a treat

Hope this helps

 

[pgomena]

I vote for air bells as well. Results just like this were the reason I went to steel tanks. I felt I couldn't rap the plastic tanks on the counter hard enough to dislodge air bells without risking breaking the tank. Also, the stainless tanks and reels provide more space between the spirals for solution to move and air to be removed, in my opinion. Others swear by plastic, but once I switched over to steel, I had no more problems with air bells, ever.

Peter Gomena

 

[Sal Santamaura]

...Others swear by plastic, but once I switched over to steel, I had no more problems with air bells...

I developed Acros in both steel and plastic. There was no change in the airbell problem regardless of tank used.