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Please help me to identify this problem (dark artifacts on negative)

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palec

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I've tried to follow instructions to meassure personal film speed (found on apug) and unexpectedly run into several problems. Some of them are beyond reach of my knowledge so I'd like to ask wise men and women here if they have any idea what is going on.

I've attached negative scans (scanned as positives, they are not inverted).

The test have been done with Kodak 400TX 120 films loaded in Mamiya RB67 SD with 127/3.5 KL lens. Films have been developed in fresh Xtol (stock made with distilled water), dilluted 1+2 with tap water (no problems after processing few hundred negatives) with 30 and 1 minute initial agitation (tried both to prevent effect of water bubbles) and 4 inversions every 1 minute for total of 10:30-12 minutes.

In first and second attachment (400TXTest0102.jpg and 400TXTest0202.jpg) you may find dark artifacts in lower right part. Both test shots are the second frames from film of same batch. Other five films from the batch are ok.

In the third attachment (400TXTest0101.jpg) you may find strange diagonal pattern which is a complete mystery to me. The lens have been focused to infinity (although set to f/22 1/2). Subject was cloth but with horizontal thread lines not diagonal. It's not either grain aliasing with scan as it's visible on negative and contact print as well. I've made mistake when taking this photo and forgot to change exposure from T to 1s and the film has been exposed to above 2 seconds and maybe I've moved the camera a little when turning off the shutter, but I doubt this could cause the pattern.

I should note that I've developed FP4+ 120 film in same developer batch as well some Arista Premium 400 135 film and have not seen this kind of problems.

Could be it's bad film batch or the film has been xrayed?
 

Attachments

  • 400TXTest0102.jpg
    400TXTest0102.jpg
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  • 400TXTest0202.jpg
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  • 400TXTest0101.jpg
    400TXTest0101.jpg
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Good morning Palec.

The artifact at the second scan looks like a kink mark to me. Somehow, pressure was applied at that spot, it was bent and as a result, it appeared once developed. I've seen something very similar to this when I tried to cut a 135 film without scissors. I hadn't tightened the film, so my attempt resulted in indentation. You might be able to spot that the surface of the film isn't perfect if you have a close look at that negative.

What's interesting about the pattern of the 3rd attachment is that it doesn't repeat itself outside the borders of the negative, so it doesn't seem to be a film defect to me. I'd also exclude x-rays. That wouldn't be limited to a single frame and the pattern doesn't look like x-ray fogging. Some examples can be seen here. If I were you, I'd invest in a grey card; that's the best approach IMHO. If you can't find one, then a smooth wall, or a piece of cardboard is the best alternative, but keep in mind that it can only be used with reflected metering, not incidence.
 
Thank you very much for quick answer and good day to you as well (now with shifted time I woked up into the day missing the morning).

With the second scan you are probably right, I forgot I had some problems when removing backing paper, the tape was still attached to the end when it sticked to the film and I might have bent the film when unsticking. I can't see anything on the surface now, but I think this is it.

I'll buy a grey card as I need to reduce variations. Since this "pattern problem" I used a brown cardboard and measured with 3 different reflective meters (spot, averaging and in-camera) to be sure. Got average Zone V reading (withing 1/5th of stop tolerance), stopped the lens 5 times to get Zone 0 and I clearly see the density above the film base (on film, haven't contact printed this yet). From what I've read so far, there should not be any density in Zone 0 (even visible on Delta 100 developed in Rodinal which should not create any fog).
 
Palec

Seems like you've got a number of things going on here. Scan 1 seems to have some liquid artifacts. It could be the film got wet before processing or that your reels were not dry, etc.

Scan 2 seems to have a scratch or "kink" mark; not sure which. If it's from the end of the roll, I'd suspect a kink.

Scan three seems just to have dust and dirt on it.

None of this looks like the fault of the film; I would bet on handling/processing "sloppiness" as a cause for all three.

Since these are tests, you can still use them for their intended purpose. It would be good to refine you technique and check another batch.

Best and good luck,

Doremus Scudder
www.DoremusScudder.com
 
Thank you, Doremus.
I tend to be careful when developing films, but I've probably underestimated possibility of accidents.
Regards of Scan 1, while I've used a dry reels, the tank might not be (or maybe it was sweat on hands with traces of photo chemicals).

I've made just quick scan, those dust particles on Scan 3 are just side effect of not cleaning scanner glass and negative, it's the diagonal pattern which interested me.
Nevertheless I agree that the film is ok, and is not fogged as this is happening within the frame and beyond this test I haven't had other problems so far.

I've posted this call for help because too many things happened at once and I've somehow lost my ground.

I'll work on improving my skills.

Best regards,
Palec
 
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