Some strange low-density spots on my film

MsLing

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I just switched to PSI version Xtol, and developed two rolls of Foma200 film in a week. Unfortunately, however, some low-density spots randomly spread on images. I use fridge to cool Xtol stock to 20℃ before processing. The first roll was processed with very fresh developer, which I dissolved 10-20 min before developed the film. When saw those awful negs, I doubted that maybe my developer was so fresh that some undissolved particles still exist. So I wait for days and processed another roll, then got the same result.



If reverse any image which with spots, dark "cores" can be seen in the center of each spot. Seems like some solid things, for example, KBr, sticked on emulsion and inhibited AgX's reduction.

 

Sirius Glass

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Are you filling to the top of the tank?
 

retina_restoration

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It is becoming widely acknowledged that Fomapan 200 (some batches) have a problem that requires an unusually lengthy water pre-soak. Blue Moon Camera advises customers to presoak the Foma 200 speed film for at least twenty minutes before pouring in the developer, to eliminate problems. (They also recommend a final wash of 20-30 minutes) I suggest you try this next time.
 
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MsLing

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Sirius Glass said:
Are you filling to the top of the tank?
Click to expand...

Yes

Well, an hour before I mixed this bag of Xtol, I used my old Xtol to develop another Foma200 and that roll was Okay, except really low density(Dmax about 0.95D). I usually buy foma's 35mm bulk film, and all negatives I showed are from the same 50m roll. I've never saw such a result in this roll with any developer.


I am going to filtrate Xtol and try one more roll tomorrow.
 

Sirius Glass

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I have not see your situation before. Usually if the tank is not filled enough it is across all or most of the negatives.
 

koraks

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Those look like air bubbles to me, clinging to the film early on in the development process. More vigorous agitation in the first 30 seconds of development may solve this.
 

Sirius Glass

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koraks said:
Those look like air bubbles to me, clinging to the film early on in the development process. More vigorous agitation in the first 30 seconds of development may solve this.
Click to expand...

Also few quick hard thumps of the bottom tank will take care of that problem right a the start of processing. I do that on a hard rubber block instead of the counter.
 
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MsLing

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koraks said:
Those look like air bubbles to me, clinging to the film early on in the development process. More vigorous agitation in the first 30 seconds of development may solve this.
Click to expand...

I follow Kodak's guidance, always continually agitate 30s after pour in developer. And hit tank for 4-5 times after agitation. I never see any air bubbles before. And IMO, a typical air bubble would only lead to a simple spot.
 

John Wiegerink

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If you look at the "spots" on the negatives the OP has posted you'll see a tiny dot in the middle of almost all the lighter density circles. Almost like maybe a teeny-tiny speck of one of the chemicals in the developer lodged itself on the soft emulsion and disrupted development in that area. I know all about Foma 200's reputation for defects and have seen it first hand myself with their 120 film version, but use Foma 200 in bulk 35mm with no problem.
 

koraks

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John Wiegerink said:
If you look at the "spots" on the negatives the OP has posted you'll see a tiny dot in the middle of almost all the lighter density circles.
Click to expand...

Good catch, I hadn't noticed that before. This doesn't look like air bubbles.

Try what @retina_restoration said and rinse the film before developing; see if that makes a difference. My best guess would be some particulate contamination that sticks to the emulsion and locally reduces development. I'd try two things:
1: Try a different developer with this film and see if the problem doesn't occur.
2: Try this developer with a different film.
At this point it's not clear to me if this is indeed particulate contamination and if so, where it originates. So try a process of elimination.
 

250swb

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I've had spots like this with a few rolls of CMS20, a halo surrounding a dark spot, and they only ever appeared in the first three or four frames, and usually only in areas of even tone such as the sky. But it's a very different film from Foma 200 and I was using Adotech developer, so there's no correlation. Never found out what caused it but definitely not a lack of agitation or not filling the tank properly. My only theory is some sort of contamination during the manufacturing process given the rest of a 36 exposure roll would be fine, but why did they only appear in the sky?
 
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MsLing

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I use coffee filter paper to filtrate developer. But anyway, still spots.

Try Rodinal next.
 

koraks

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retina_restoration said:
I seriously doubt that Xtol is to blame. Fomapan 200 is known to have problems
Click to expand...
So how come a different film produces the exact same problem?
Also, this particular problem is unknown to me in Fomapan 200 or any other Foma film. I've used Fomapan 200 in 135, 120 and sheet film formats. I've never seen this.
 

retina_restoration

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koraks said:
So how come a different film produces the exact same problem?
Also, this particular problem is unknown to me in Fomapan 200 or any other Foma film. I've used Fomapan 200 in 135, 120 and sheet film formats. I've never seen this.
Click to expand...

There's a distinct possibility it is a user technique problem as well. Those marks look suspiciously like air bells (but maybe not).
I recognize that not everyone has had problems with Fomapan 200, but it seems to be enough of an issue that Blue Moon Camera has issued a warning to buyers that it needs an extended presoak to reduce faults on their negatives.
 

koraks

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Air bells was my first thought; see above. But the darker spot in the center of these defects and their overall geometry upon closer observation doesn't seem to support this.
I don't know what Blue Moon relies on in their recommendation. I'm aware that there are problems with recent batches of Foma films that have stubborn anti-halation dyes that require either a very long soak, or a brief soak in a concentrated alcohol/water mixture to remove satisfactorily. For all I know this is what they're aiming their advice on. This is quite distinct from the notorious problems of Foma 200 exclusively in 120 format that are not affected or fixed by whatever process variable as they are legitimate emulsion defects.
 

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My 2 cents:

  • This for all the world looks like air bubble with the addition of some kind of contaminant
  • A 3 min prewet would likely help
  • Tapping the tank after every agitation to dislodge air, as suggested upthread, is pretty much mandatory
  • The "contaminant" could be improperly mixed or not fully dissolved Xtol with particles in suspension
  • The "contaminant" could be from failing to use distilled water to make up the developer and using tap water with particulates in it
  • The failures of Fomapan 200 are predominantly seen on the 120 rollfilm. It is characterized as emulsion chip off and results in black spots in the final image.
  • I have seen some emulsion blemishes in 35mm occasionally as well, but it is far less common. These seem mostly to be inconsistencies in the emulsion rather than chip off and manifest as small light colored spots. I have seen this with both factory loads and bulk film so it is definitely an artifact of the film manufacturing. But, I like I said, it's not all that common.
 
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MsLing

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retina_restoration said:
Did you try the 30 minutes pre-soak??
Click to expand...

Yes, I did. However, it didn't work. I cut some excerpts from the same roll, and divided them into several groups: Xtol without pre-wash, Xtol with 30min pre-wash, Rodinal without pre-wash, 510-Pyro without pre-wash. Only strips developed by Xtol showed those spots.
MsLing said:
View attachment 405064
Ahhh... FP-100 sheet was also polluted by Xtol
Click to expand...

And I tried 35mm FomaPan100, 35mm HP5+ and 4x5 FP-100 sheet, spots happended on all these film developed with Xtol. Image I quote is FP-100. I've used Xtol for a long time and I firmly sure that this Foma200 bulk roll I own had never got any wrong.
 
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MsLing

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chuckroast said:
Tapping the tank after every agitation to dislodge air, as suggested upthread, is pretty much mandatory
Click to expand...

That's what I always do.
chuckroast said:
  • The "contaminant" could be improperly mixed or not fully dissolved Xtol with particles in suspension
  • The "contaminant" could be from failing to use distilled water to make up the developer and using tap water with particulates in it
Click to expand...

Solution was mixed totally under Kodak's guidance. And I filtrate developer this afternoon, #14 mentioned. Distilled water is the only thing I use for photographic chemistry. Distilled water, as an industrial products, is always provided in a really low price. Therefore, there's no reason to use tap water.
 

retina_restoration

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Then I think you've identified your batch of Xtol as being the problem. Discard it and get some from elsewhere. Do you have a record of the batch number or whether it was made by Sino Promise or Photo Systems Inc.? I suggest you do NOT buy any Xtol made by Sino Promise, as they effed up a lot of the Kodak branded chemistry.
 
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