Negative problem: black specs (Efke IR820)

[pdeeh]

I normally manage to produce very clean negatives, but my most recent roll has ended up with a forest of black specs over all areas of every frame. An example is attached (uninverted negative scan).
These are not dust marks from careless scanning, by the way; I've looked at them on a lightbox with a 10x jeweller's loupe, and they appear to be embedded in the emulsion.

Details:

EFKE IR820 (135) - frozen since purchase; removed from freezer to 'fridge for 12 hours, then 'fridge to room temperature for 2 hours before loading.
Loaded into OM-1n MD in total darkness, and shot using 680nm red filter.
Knowing that this emulsion has a certain notoriety for fragility and softness, I was almost obsessively scrupulous about handling it, and all the fluids in contact with the film were within a degree (indicated) of 18C
Unloaded from camera and into Paterson tank in total darkness.
Prewet (as per Efke recommendation) with plain tap water.
Rodinal (APH09) 1:50 for 13½ minutes @ 18C, initial 30s gentle agitation, 3x gentle agitations every 60s. (water for Developer mixing was boiled + filtered)
Plain tap water stop for 30s
Ilford Rapid Fix 1:4, 4 minutes, 30s initial agitation, then 15s agitation every 60s. (Fixer has had less than 10 rolls through, although one or two were C41 processed in B&W chemicals, but the fixer is filtered on return to its bottle before re-use)
Ilford wash regime in plain tap water (5, 10, 20, 20)
Final wash in deionised water with a drop of Ilfotol.
Hang to dry in humid (no dust) bathroom for 12 hours.

I'm inclined towards the fixer being the culprit (so I'll dump that batch and make fresh), but I would welcome any alternate diagnoses ...

many thanks

 

[pdeeh]

thank you Michael.

hmm now I come to think about it more carefully, that batch has had quite a few more rolls through it than I first thought.
It still passes a clearing test (under a minute), but obviously that's not the whole story.

How annoying, there's not much of this stuff left and that roll is pretty much unprintable.

Oh well, these things happen. Lesson learned.

 

[tkamiya]

Can you tell if those spots are part of the image or some foreign object embedded in the emulsion? Sometimes, you can tell them apart by looking at the negative at an oblique angle with varying light under high magnification.

I am kind of doubting weak fix, but it is entirely possible something was contaminated. It is even possible there was some repair done to your water system somewhere and junk was flowing through during wash cycle. Is your wash water filtered? (other than the last step of course)

 

[martinhughesireland]

Think this is normal enough for this film just before it was discontinued. Was the reason i stopped buying it.... Its a problem with the film not your fixer etc.... Lots of us had this problem, we moved to ilford sfx and rollei ir 400

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[Mark Feldstein]

Think this is normal enough for this film just before it was discontinued. Was the reason i stopped buying it.... Its a problem with the film not your fixer etc.... Lots of us had this problem, we moved to ilford sfx and rollei ir 400

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Very interesting point. If Martin's correct, you might want to check the batch number and if they're the same on what you've got left, snip a couple of frames off, process and loupe it. It may save you a lot of aggravation.
Mark

 

[bsdunek]

I had a similar problem with their IR film. Just one batch was that way. Very annoying!

 

[pdeeh]

Expiry 03/2013, Emulsion No. 111007.

Oh well I suppose I can flog it on eBay ... "RARE LOMO!!!" etc.

 

[Alex Muir]

I also had problems with the last IR 820 films I used. It's a pity because the emulsion was capable of producing nice IR effects. Alex