What are these spots? (probably easy)

[villagephotog]

I'm guessing the answer is fairly obvious to experienced B/W developers, but hoping somebody can clue me in to the cause of these dark spots in an area of sky from a test negative. (Obviously, they are white spots on the negative.)

These spots are on a couple of frames out of the roll, but not on all of them. Film is Pan-F developed in XTOL 1+1 mixed using distilled water. In a Paterson 2 tank, using a Samigon reel. I used the Paterson twirly agitator for the first 30 seconds, then 3 inversions every minute thereafter. I gave the tank a solid tap on the counter after each set of inversions. Distilled water stop. Normal fixation in Ilford Rapid Fixer, also mixed using distilled water. Thoroughly washed, but in tap water. No wetting agent. Hang dry overnight.

 

[MattKing]

Are the spots visible to the naked eye when you look at the negative under magnification?
Do they appear as somewhat more transparent areas in the negative?

 

[villagephotog]

Are the spots visible to the naked eye when you look at the negative under magnification?
Do they appear as somewhat more transparent areas in the negative?

Yes, they're easily visible on the negative under a loupe. The two very dark spots look almost white on the negative, and the other, fainter, dark spots do indeed look somewhat more transparent than surrounding areas of the negative, with their transparency proportionate to how dark they appear in this scan.

This is a 120 negative by the way. The diameter of the two very dark spots is roughly .25 millimeter on the negative.

 

[Andrew O'Neill]

When you say white on the negative, do you mean they're lighter in tone/density? Could almost be from airbells...

 

[villagephotog]

When you say white on the negative, do you mean they're lighter in tone/density? Could almost be from airbells...

Yes, 'white' was a bad word. They are lighter in density. The two very dark spots are quite light and the other dark-ish patches are a bit lighter in density than surrounding areas of the negative.

 

[koraks]

Looks like bubbles. Tap the developing tank firmly on the counter after filling it up. Agitation by flipping the tank may also work better than the twirly stick thing.

 

[MattKing]

I'm guessing airbells as well.
A solid tap on the counter prior to the twirling might have prevented the problem.
I'm a fan of using a pre-soak, but a recommendation for that might derail this thread, so I'll just stay quiet about that .
FWIW, I too use Paterson tanks, Samigon (or in my case, AP branded) reels for 120, and X-Tol, although in my case it is replenished X-Tol.

 

[villagephotog]

@ koraks & MattKing

Thank you for the input, gentleman. It did occur to me when I was writing the description of my workflow that I have not been tapping the tank right after filling it up and before I started the twirl agitation. So, that seems like a good step to take and see if it keeps the spots away.

 

[jimjm]

I use Paterson tanks as well, for 35mm and 120, but I use inversions from the start and don't bother with the twirl stick. I tap the tank on the counter after the first 30-sec agitation, and after every agitation for the rest of the development time.
I agree with the other posters that this just looks like air bubbles.
Unless you've got really hideous tap water, it's probably not necessary to use distilled water to mix your chemicals, or for the final wash. Just use a final dunk in Photo-flo or other wetting agent mixed with distilled water, before hanging to dry. No wipe or squeegee of the film needed.

Good Luck!

 

[villagephotog]

I use Paterson tanks as well, for 35mm and 120, but I use inversions from the start and don't bother with the twirl stick. I tap the tank on the counter after the first 30-sec agitation, and after every agitation for the rest of the development time.

Good Luck!

I'd be fine doing inversions from the start, but I was worried about the time it took to get the lid on the Paterson tank to allow for non-leaky inversions; takes me a few seconds to get it to seat correctly. Either you're faster than me, or those few seconds of non-agitation aren't really a problem I will take this under advisement.

 

[MattKing]

Either you're faster than me, or those few seconds of non-agitation aren't really a problem I will take this under advisement.

They aren't a problem.
The developer is probably still moving a bit while you are attaching and burping the lid - moving developer equals agitation.

 

[Andrew O'Neill]

@ koraks & MattKing

Thank you for the input, gentleman. It did occur to me when I was writing the description of my workflow that I have not been tapping the tank right after filling it up and before I started the twirl agitation. So, that seems like a good step to take and see if it keeps the spots away.

Hey wait a minute! I beat Matt and koraks to the potential air bell problem!

 

[Sirius Glass]

I got a slab of linoleum from an art store that I use to thump the tank several times quickly with each chemical change.

 

[jimjm]

I'd be fine doing inversions from the start, but I was worried about the time it took to get the lid on the Paterson tank to allow for non-leaky inversions; takes me a few seconds to get it to seat correctly. Either you're faster than me, or those few seconds of non-agitation aren't really a problem I will take this under advisement.

Probably takes me 3, 4 or 5 secs to seal the lid, then burp it like tupperware to prevent any leaks. You get quicker with practice, but like Matt said, the developer is still moving around in there during this time.
I hit the button on the timer just as I complete pouring the developer in, seal the lid then agitate until the 35 sec mark. A few seconds here or there won't make a difference unless you're using really short development times, say under 5 mins, which most manufacturers don't recommend.

 

[MattKing]

Hey wait a minute! I beat Matt and koraks to the potential air bell problem!

Well, you did say "almost"

 

[John Galt]

UFOs . . . . come on guys . . . air bubbles? really?

 

[mshchem]

Kodak has always recommended agitation every 30 seconds for 5 seconds with small tanks. Twist and invert at least 3 times, I usually did it 5 times. You aren't going to over agitate as long as you use gentle inversions.
A gentle wap is all you need. When in doubt agitate, don't do the "Martini shaker" smooth rolling inversions. Make sure there's no residual photo flo.

That's pretty substantial marking. Makes me wonder if something "sneezed" a few micrograms of some sort of oil or silicone on the film. ???

If you are looking at only air bells, stepping up your agitation you will probably never see it again.

 

[villagephotog]

UFOs . . . . come on guys . . . air bubbles? really?

I will only add that I am on the Eastern Seaboard, not too far north from where all those Navy pilots have been chasing Things That Don't Fly By Any Known Physics.

So, if better agitation does not make the spots disappear, well then, there you have it.

 

[John Galt]

I will only add that I am on the Eastern Seaboard, not too far north from where all those Navy pilots have been chasing Things That Don't Fly By Any Known Physics.

So, if better agitation does not make the spots disappear, well then, there you have it.

Well then, there you go . . Better agitation!!!

 

[choiliefan]

Air bubbles.
Another vote for water pre-soak and rapping the bottom of tank after filling with developer.