Trouble with Neopan Acros 100

Because so many people have expressed an appreciation for Fuji's Neopan Acros 100, I have been working with that emulsion on and off for 2 years, mainly in my pinhole cameras - if for no other reason than its ridiculously pinhole-friendly reciprocity. However, I have found that I almost always have problems with "pock marks" (conspicuous dark round spots with lighter outer rings) on the negatives that appear ONLY on this film (I use several Ilford and Kodak emulsions as well).

See:

(This is one corner of a 6 X 18cm neg, and this area represents approximately a 2X2cm area)

Process:
I develop all my own film, and I have used Neopan Acros in combination with Rodinal and D76 in various dilutions. I used Rodinal exclusively for the first year or so and thought perhaps it was causing these dark spots with lighter rings (I hope they are easily identified in the image - click to see full size, please), but they appear when using D76 as well. (The above negative is processed in D76, by the way.)
I have been using a presoak for 1-2 minutes with all my films and I measure temperature carefully. All chemistry is maintained within 1-2 degrees F at all times. I have been using an indicator stop bath, but I experimented by using two water rinses instead, but that change had no effect. I have used a rapid fix and I have used a hardening fix - the marks show up either way. I do a rinse after fixing and then a 2 minute Kodak Hypo Clear bath before a final wash. Oh, and I always use mineral-free (reverse osmosis) water for my chemistry.
So, I have to wonder - is this just a defect of the emulsion, or what? Does anyone know why I am getting these marks, and what I might do to prevent them? Thank you.

Paul

I doubt that the emulsion is defective, The FIRST thing that comes to mind is that your pinhole camera has a slight, 'biased in one area', light leak. - David Lyga

What batch is your current Acros film? I have some older 120 rolls at home and would be willing to plop one in the mail for you to try out. I have had zero issues with it and have developed in D76 and Harvey's 777 Panthermic. Both yield perfectly repeatable results with no emulsion defects. PM me your address. You can send me one of your rolls in return if you like.

Despite your presoak, they look like air bubbles to me. Are you very diligent at thumping the tank after agitating?
Here are some air bubbles of mine.

I agree with Winger, looks like air bells. You are not prerinsing long enough, I use a minimum of three minutes, and shake the holy whoopies outta the tank instead of gentle inversions while soaking. It sounds counter productive, but I've never gotten air bells from it. I use regular inversion agitation with developer.

Thomas Bertilsson said:

What batch is your current Acros film? I have some older 120 rolls at home and would be willing to plop one in the mail for you to try out. I have had zero issues with it and have developed in D76 and Harvey's 777 Panthermic. Both yield perfectly repeatable results with no emulsion defects. PM me your address. You can send me one of your rolls in return if you like.

Click to expand...

Hello Thomas.
Batch #2015-12 167011Q
Thanks, I will contact you

Paul

To me it looks like there is some kind of contaminating particles/drops that make the developer extra active ( causing the dark spots ) and thus exhausting the surrounding developer ( causing the brighter rings ). I don't know if the Acros emulsion is more sensitive to atract dust or drops. It may be particles that increase the PH-value. Just a theory.

Karl-Gustaf

Rick A said:

I agree with Winger, looks like air bells. You are not prerinsing long enough, I use a minimum of three minutes, and shake the holy whoopies outta the tank instead of gentle inversions while soaking. It sounds counter productive, but I've never gotten air bells from it. I use regular inversion agitation with developer.

Click to expand...

You know, that's what I thought those marks looked like, but I discounted the possibility because I WHACK the heck out of my (steel) tanks when I presoak and the first couple of minutes after the developer goes in. I'm a bit casual about my presoak times and I am certain that the presoak often goes far longer than 2 minutes... I have a hard time accepting the notion that I am not working hard enough to dislodge air bubbles - but perhaps its true. Do you suppose my mineral-free water is working against me when I presoak with it? Is it possible that a presoak is not the right thing for this particular film? (I've heard it said that some films potentially fare better when the first liquid the emulsion encounters is the developer)

Thank you for your suggestions. Any other ideas?

No ideas in addiction to what others have already proposed. Just a data point: I have developed neopan acros 100 to my great satisfaction without those kind of marks in id-11 1+3 without any presoak.

Francesco_from_Rome said:

No ideas in addiction to what others have already proposed. Just a data point: I have developed neopan acros 100 to my great satisfaction without those kind of marks in id-11 1+3 without any presoak.

Click to expand...

Ditto here (HC110 1+63) -- I never pre-soak.

paulbarden said:

You know, that's what I thought those marks looked like, but I discounted the possibility because I WHACK the heck out of my (steel) tanks when I presoak and the first couple of minutes after the developer goes in. I'm a bit casual about my presoak times and I am certain that the presoak often goes far longer than 2 minutes... I have a hard time accepting the notion that I am not working hard enough to dislodge air bubbles - but perhaps its true. Do you suppose my mineral-free water is working against me when I presoak with it? Is it possible that a presoak is not the right thing for this particular film? (I've heard it said that some films potentially fare better when the first liquid the emulsion encounters is the developer)

Thank you for your suggestions. Any other ideas?

Click to expand...

I always presoak, a habit I acquired using rotary processing. I set my timer for three minutes, add tempered tap water, and shake the daylights out of the tank for about 30 seconds, bang the tank on my hand a couple of times, and agitate same every 30 seconds. I dump water, add developer, inversion agitation for 30 seconds followed by 2-3 sharp raps of my tank, followed by 4 inversions every minute and a sharp rap of the tank. I haven't had air bell issues in 40 years.

Rick A said:

I always presoak, a habit I acquired using rotary processing. I set my timer for three minutes, add tempered tap water, and shake the daylights out of the tank for about 30 seconds, bang the tank on my hand a couple of times, and agitate same every 30 seconds. I dump water, add developer, inversion agitation for 30 seconds followed by 2-3 sharp raps of my tank, followed by 4 inversions every minute and a sharp rap of the tank. I haven't had air bell issues in 40 years.

Click to expand...

That is mighty close to my own process and like yourself, I have not had air bubbles on film in the forty years I have worked with the various types - only recently, and only the Neopan Acros. Or so it seems.

I am not sure what those marks are, and I never do a presoak. Are you filtering your developer? The reason I ask is, I was having problems w/ similar marks when using powdered developers, as well as lot of smaller marks too. Now I always filter my developer through a funnel w/ a regular paper coffee filter (you have to put in a few small, clean rocks in the bottom to avoid problems while pouring the liquid in). End of spots. I think mine was undissolved "hot" spots. Developer pieces that couldn't be seen, looked like liquid, but were actually still a little clumped together.

If you have trouble with air bubbles in an inversion tank, try adding ONE DROP of photoflo per 500mL of developer. Much more than that and you will get foam (really bad) but the one drop is enough to reduce surface tension and get rid of air bubbles.

However I've only had problems with bubbles hiding under the tops of spirals, never sticking around in the middle of a frame like that. I don't typically presoak rollfilm unless the tank is wet already and I run the risk of dribbles on the film.

In case you have particulate contamination of your developer, you could/should try a different one and/or try filtering your developer working solution through a coffee filter immediately before use. If this is sheet film, I would suspect film contamination during loading/handling.

I never pre-soak and can't recall any issues with air bubbles. I was told many years ago (actually by the science master who ran the school photo club!) that film emulsions and commercial developers contained a wetting agent to assist smooth developing.....no idea if this was correct !

Paul I see you are in Oregon. If you are in Portland I would be happy to process a roll for you to see if the problem is still there. I am in Portland and Acros is my main film in 120 and have never seen that problem.
Dennis

Looks like air bubbles to me!

It's not you; it's the film. From another recent thread, with the relevant portion in bold italics:

Sal Santamaura said:

...Three factors caused me to decide against Acros. First, like 100 TMAX, its emulsion side is so shiny that, short of wet mounting, Newton's rings are unavoidable in a glass carrier. Second, with inversion agitation, I was unable to avoid air bells and resultant circular underdeveloped spots. Without a presoak, with one presoak, with two presoaks, no way. Finally, the 120 base, although no thinner than many other films', is extraordinarily flexible and difficult to load on reels, whether steel or plastic..

Click to expand...

To me, your negatives look like they came in contact with some contaminant. Eliminate a few variables known to cause these spots: mix the developer and wetting agent with distilled water and filter any water that comes into contact with the film (a 20-micron filter is sufficient).

i've been doing acros 120 in d76 1:1 with no presoak, no nothing, just regular agitation 5 seconds every 30. Never seen this problem.

Maybe something in your water ... especially hard water where you are?

It seems a few of you missed the fact that, in my original post, I stated that all of my chemistry is made using only reverse osmosis water, which I measure as having no more than 3ppm of total dissolved solids. And so, I very much doubt water quality is an issue. Do you concur?

I've stated this before and I will again;
All fuji B&W films benefit tremendously from a full complete vigorous initial agitation of at least 45 sec preferably one full minutes (no matter what you used to do back in the day with tri-x and d-76).
I had a full career shooting and processing literally thousands of rolls of fuji and others and for FUJI B&W films I cannot stress this enough EVEN WITH A PRE-SOAK!!

A FULL COMPLETE VIGOROUS INITIAL AGITATION OF AT LEAST 45 SECONDS PREFERABLY ONE FULL MINUTE.

If you are not doing this then I don't want to hear any more. Fuji films are different and that is that. Deal with it or keep having problems. I hate to be harsh on this point but Fuji recommends a longer initial agitation than Kodak or Ilford and they do this for a reason. If you want some proof take a snip test of a Fuji Ilford and Kodak films and see how long each one starts to change. Fuji takes longer, and if you stop the initial agitation *even with a presoak* then the *potential* of uneven processing problems can and will arise. I know this because back in the 90's and early 2000's when I was doing a commercial film processing for wedding photography we had initial problems with any fuji B&W films: and when we switched *no matter the developer* to a full minute of initial agitations all the odd behavior went away, and we tried everything else.
It does not matter the developer type it can only help especially with more diluted developers such as Rodinal 1:75 and above.
I've written on this more and I guess I'll have to say it again.
With Fuji B&W films Acros 100 Neopan 100 SS Neopan 400 Neopan 1600 A FULL COMPLETE VIGOROUS INITIAL AGITATION OF AT LEAST 45 SECONDS PREFERABLY ONE FULL MINUTE.

thank you, rant over. don't let me catch you again. stay off my lawn and turn down that rap music

paulbarden said:

It seems a few of you missed the fact that, in my original post, I stated that all of my chemistry is made using only reverse osmosis water....

Click to expand...

Welcome to APUG.

Richard Sintchak (rich815) said:

Welcome to APUG.

Click to expand...

An inherent problem with thread based conversations like these is that very few people actually read all of the information before answering. I'm guilty of it too, and sometimes answer questions that have not been asked.

Thomas Bertilsson said:

An inherent problem with thread based conversations like these is that very few people actually read all of the information before answering. I'm guilty of it too, and sometimes answer questions that have not been asked.

Click to expand...

I get that. Its something we've all done, one time or another. I just wanted to reiterate this detail. No worries!