Baffled by this result - help

[gregg]

OK - almost 25 years in the darkroom and I'm baffled by this result.

Notice the "pinhole" white spots on the dark hair. (100% crop of 2800dpi scan)

HC-110 (H) with Fuji Neopan 400 for 9.5 minutes (agitation at pour, 6 and 3 minutes).

Indicator stop bath mixed per Kodak's guidelines.

Ilford fixer mixed per Ilford's instructions - 5 minutes - agitation every one minute. Wash per Ilford's economic guidelines (I've fixed/washed this way for 15+ years.)

These white "pinholes" occur in every roll of Neopan 400 and HP-5+ I've developed in HC-110 with Stop Bath and standard non-hardening fix.

They DO NOT happen when developed in Diafine using a water stop and the same fixing/washing methodology.

Not sure what is going on here but could it be the stop bath? I've tried "full strength" and "half strength" - everything in HC-110 looks the same. All chemicals mixed with distilled water.

I'm pretty much convinced Diafine is working for me and doesn't show this result in the black/shadows, but if I need to use HC-110, this mystery remains. CSIs (celluloid scene investigators) should pay close attention...

 

[cmedin]

sitemistic: if you don't mind going slightly off-topic... you mention thin emulsion films. I've been reading up on Diafine recently, and how it works, and I am wondering if the films that are seeing a significant speed increase (TriX, PlusX) are doing so because of thicker emulsions absorbing more of the Diafine solution A to react with B in the second bath.

What are your comments on that?

As for the original post, it looks similar to my Caffenol negs... they turned out a lot more 'noisy' though with fine detail than I expected. Could it possibly be a temp issue between baths?
'

 

[gregg]

I tend to agree with sitemistic's appraisal and the acid stop bath. When I use HC-110 again I'll try plain water...

I'm REALLY cautious with temp - no more than a 1-2 degree difference. HC-110 is always 20C, stop and fix as close to that as possible so that shouldn't be a contributing factor.

As for thin/thick emulsion - all modern films are pretty thin. T grain (TMAX, Delta, Acros) need more time in Diafine (5+5 minutes) because of their grain. "Thick" films like Efke 25/50 may require more than 3+3 too.

 

[cmedin]

sitemistic, you have me interested enough to try Caffenol again, without a stop bath this time. I've heard a lot of good about it, but when I did try it it ended up sharp but with an insane amount of what looked like digital noise. Perhaps it was the stop bath, and with the 30+ min dev times of Caffenol I can't imagine a water bath replacement would affect much!

 

[titrisol]

Well, you see it when you use the stop bath and do not see it when you do not.

Next time try HC110 and water stop with 1 or 2 quick rinses. Should be enough
If there are still pinholes then another iteration of troubleshooting is needed (but I doubt it)

 

[David Goldfarb]

In theory an acid stop shouldn't cause pinholes with modern films, but I'd agree you might try replacing it with a water rinse and seeing if it helps. I don't use an acid stop myself.

I don't know that there are any real old-style thick emulsion films anymore, like Super-XX. Efke films are based on Adox formulas (and are even sold under the Adox trade name today from fotoimpex.de), which were thin emulsion films.

 

[Benjamin Marks]

If you tend to use your fixer to exhaustion and want to continue to do so, you could also cut your dilution of acetic acid by half in your stop bath. If it's not pinholes in your emulsion, you could have particulate matter in your water -- this would be mainly visible in areas of low density (shadows, dark hair etc.). You can test for this by running your usual process, but with distilled water and see if you still have the problem.

Ben Marks

 

[JoeV]

What Pinholes?

What Pinholes?

Okay, maybe it's just me, or my monitor, or the quality of the film scan, but I don't see what I would call artifacts of emulsion pinholes. There's a few lighter spots visible near the hairline in the top right quadrant, but these can't be pinholes, since the highlights on the nose are brighter than these spots. True pinholes - where gelatin emulsion has been blown totally off the plastic support - will show in the positive image as spots that are maximum (think 'Zone X') white.

If you are reusing your fixer to exhaustion, I would recommend filtering it well after each use; particles of metallic silver that have gone out of solution can deposit onto the emulsion during the fixing step. And, of course, distilled water, or at least well-filtered tap water, should be used on all process steps.

I personally haven't seen pinholes with modern panchromatic B/W films that are attributable to acid stop bath, but it does easily show on Arista's APHS ortho lith film, which is an even thinner emulsion, on a thinner plastic support. For APHS I definitely use a water stop.

~Joe