Edge marks on 120 b/w negative

bernard_L · Oct 17, 2018

After developing a 400TX 120-size film (D-76 1+1, 10min@20°C), I had a quick look using a method that shall remain name-less. On 3 or 4 of the 15 frames, and only these, I see spurious marks near the edge. Generally the neighbor frames are free from such marks. Based on that evidence, I would rule out surge marks. And suspect mechanical stress at/around the friction loading mechanism of the Paterson reel. I can't remember whether loading was problematic. Whole frame and contrast-enhanced detail are attached.

Do you agree on the probable cause?
Other possible causes?

Yes, I know, Hewes stainless steel reels rule. I need a diagnostic before evaluating remedies.

jimjm · Oct 17, 2018

Bernard - are you sure your reels were completely dry? If this occurred along the edges of the frame where the film touches the reels, and there was any water on the reels, it could account for the inconsistent splotchy marks you see here. If the film sat for a bit before you poured in the first chemicals, this water could soak into the film along the edge and affect the development density in those areas. I'm sure there are other possible causes, but this is the first that comes to mind. I've been using Patersons for 30+ years and never needed to switch to steel reels. Just a personal preference. It is important to keep them clean and dry before attempting to load film.

bernard_L · Oct 17, 2018

My OP is missing something that should be present in any question about problematic negatives: a picture of the negative itself. The edge marks are barely visible. One can also make out a faint reflection of another verboten device used to bring you this picture. The main point here is that the rebate is clear. Which does not rule out mechanical stress, which may act different from added light exposure.

MattKing · Oct 17, 2018

This looks like the sort of uneven development occurring near bubbles that can sometimes happen when there is either too little developer in the tank or a residue on the reels that alters development locally.

bernard_L · Oct 17, 2018

jimjm said:
Bernard - are you sure your reels were completely dry?

Yes, I'm sure. I developed a few films over roughly one week, but never used one of the reels that I had left to dry a few days before; each time a reel that had been unused for weeks. And, after reading (a year ago??) about the supposedly ill effects of photo-flo I gave my reels one turn in the dishasher, and since then wash them with hot water from the faucet.

Anyway, this addresses tentative answers to the question: "why did the film not load perfectly smoothly" (which I am not even sure actually occurred).
My question is: assuming the loading was a little difficult, is it plausible that mechanical stress at/around the autoload mechanism (spring-loaded steel ball, or whatever) could cause the observed marks.

Mainecoonmaniac · Oct 17, 2018

MattKing said:
This looks like the sort of uneven development occurring near bubbles that can sometimes happen when there is either too little developer in the tank or a residue on the reels that alters development locally.

+1.

bernard_L · Oct 17, 2018

I'll buy the bubbles explanation. Possibly, after many problem-free developments, I became complacent and skipped the "bottom-tap" after pouring the developer.

Thanks to jimjm, MattKing, and Mainecoonmaniac for your comments.

mshchem · Oct 17, 2018

If it was stress "whitening " of the base film plastic, you should see it in the margins. I used Paterson reels since mid 70's. Every now and then they balk. Some of these reels are 40 years old. I found some with rusty steel balls etc. I bought a bunch of new reels from a store closing. New reels are a treat.

canuhead · Oct 18, 2018

bubbles

Hatchetman · Oct 18, 2018

not enough developer in the tank

Ben 4 · Oct 18, 2018

Yes — bubbles: I have experienced this too. I now use at least 550ml of developer for 120 in my Paterson tanks (10% more than Paterson specifies).

--Ben

jvo · Oct 22, 2018

yes, bubbles... it caused me to switch to ss, (not hewes), never looked back

bernard_L said:
.... I need a diagnostic before evaluating remedies.
View attachment 209604 View attachment 209605

i'll bet you use a map before, driving, too!

bernard_L · Oct 23, 2018

jvo said:
i'll bet you use a map before, driving, too!

So many posts propose a solution in search of a problem... SO maybe it's worthwhike to remind comon-sense rules.

Edge marks on 120 b/w negative

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