Clear Spots in Emulsion?

[bvy]

More problems. Developed two rolls of Acros 100 (120) tonight in a 1 liter Paterson tank. Several frames have clear areas that either got no development or where the emulsion is damaged. These were processed in HC-110, dilution E, at 68F for 8:00 -- regular agitation (eight inversions initially, four at the top of every minute); vinegar/water stop (1+4), constant agitation for 1:00; Ilford rapid fixer, constant agitation for 5:00. Ten minute rinse and one minute soak in PhotoFlo. The developer was mixed from syrup using distilled water.

I did have trouble with the tape coming off of one of the rolls, and noticed some residual that came off easily with my thumb when I hung it to dry. The problem is on both rolls, though it's more problematic with the roll on the top reel (not the roll with the tape however).

Also, these rolls were exposed last summer but stored in a cool dry place.

There was a water main break this morning, but we only lost pressure for about an hour. Even so, the stop and rinse are the only baths that I used tap water for.

Ideas? I used the same combination last week, and all came out fine. The pictures were taken through a loupe. I'll scan them tomorrow. Thanks for looking.

 

[MattKing]

Any chance it is due to damage to/dirt on the backing paper? Could the rolls have got wet?

 

[bvy]

Not wet, but here's something else I discovered in going through my notes... The camera (a Yashica Mat 124G) took a fall onto concrete halfway through the roll that was the top one in the tank. The frame that was ready to expose when that happened looks okay, but the next one is the one pictured, and it's also the one that looks the worst. Hmmm...

 

[MattKing]

I wonder if some of the interior flocking material was dislodged by the fall, and made its way to the film.

 

[zanxion72]

It is most likely that the emulsion has pealed off from the base. It could be due to backing paper stuck to the emulsion due to humidity. Do you still have the backing paper of that roll?

 

[Xmas]

It is most likely that the emulsion has pealed off from the base. It could be due to backing paper stuck to the emulsion due to humidity. Do you still have the backing paper of that roll?

It is important to inspect backing paper and retain until the processed negatives are inspected.
Only open wrappers before loading film it is not a waste of time...

 

[bdial]

After the fall, did winding become more difficult?
If all was well prior, it sounds like the fall may have distorted the back and is causing the film to bind.

 

[bvy]

I don't remember winding becoming more difficult -- though it may have been temporarily. The camera landed on the bottom corner (where the film door turns 90 degrees) and took a little dent there. The camera still works and winding is very smooth.

I do still have the backing paper. I'll inspect later when I'm home and report back. What should I be looking for?

 

[Xmas]

Any witness threads that the paper was attached to the emulsion temporarily use a loupe or camera lens.

120 backing paper is a significant risk.

 

[bvy]

Just to bring some closure to this... First, nothing suspect on the backing paper really. The most problematic frame (in the pictures I posted a few days ago) was the unexposed frame wrapped around the spool at the point of impact; the two adjacent frames show the problem too. I'm pretty sure some debris got into or onto the film. The emulsion looks fine (undamaged) except maybe in one or two places; and there's a small circular "dent" (not quite a puncture) on one of the adjacent frames.

The only baffling thing, then, is a few similar looking clear areas on the other roll that I developed with this one. I wonder if some debris got wrapped up in the damaged roll and came loose during processing, finding its way to the roll on the bottom reel. It could be a completely unrelated problem too...