How I removed base fog from old film stocks

May 27, 2019

Daniel Keating

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How I removed base fog from old film stocks

May 27, 2019

Daniel Keating

We love it when our readers get in touch with us to share their stories. This article was contributed to DIYP by a member of our community. If you would like to contribute an article, please contact us here.

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A lot of us analog film photographers love to shoot film but new film stocks can be pricey. A 100ft roll (30meters) of fresh Tmax is about $80 US these days. Deals can be had on “vintage” (expired) film but many purists will disregard this as results are inconsistent and sometimes just awful. I teach on the side and I am always looking to save student monies but give them a positive experience so there is no discouragement.

I took a chance on 2-400ft cans of some 1988 expired CFX 5538. This is film designed to be used by a radiologist to film radioactive dye injected into the bloodstream and the function of your heart in the process of it pumping the dye through. While 1988 was only 31 years ago the film was aged terribly. Horrendous amounts of base fog to try to scan or print through—it was pretty much 800ft total of scratch test leader that I only paid $20 for. My guess was it was a storage locker repossession/flip and it was just left to bake in some U-Store-It unit for years with no climate control. Here is a sample of what I was getting from my initial developing:

Pretty miserable so I shelved the film for a year.

I’ve seen attempts to clean these remnants up by some folks using potassium bromide, cold water used to mix the developers and anti-fog agents like benzotriazole with limited success. I thought to myself, maybe it’s not one method, but rather a combination that would be better…?

I went back to that horribly heat-fogged film and used a developer that I found works generally well with old film, D78 ( Glycin, Sodium Sulfite, and Sodium Carbonate) for 10 minutes time at room temp and it was still toast. I then made up a 1% solution of Benzotriazole ( 1 gram to 100ml water) and grabbed some small ice cubes. I made a batch of the D78 with 150ml room temp water to dissolve the chemicals and added 5 small cubes of ice, topped off to 300ml for a single reel Nikor tank and added 6 drops of the 1% Benzo. The developer was now 52F and with the lower temp and small amount of restrainer I figured I would need to increase the time. I went to 18 minutes and here is the comparison:

The strip on the left is the CFX5538 film with straight developer and normal time. The strip on the right is the chilled down developer mix with the 6 drops of Benzo and extended time—SAME FILM. From the strip on the right:

I think we can all agree this is a marked difference from the wall clock scan at the start of the article – the same film with vastly different results. Some of the readers are saying OK—but what about older film and developers I might have like D76 or Rodinal? What’s in it for me? Here is some military surplus Tri X from 1962 in D76 1+3, 50F and 6 drops of the 1% benzo for 40 minutes:

Here is some DuPont Superior 3 from 1952 in D23 50F 9 drops of Benzo:

Digital Camera

More Dupont Superior 3 from 1952 in Rodinal—for this I used 10ml, 2 hours stand and 6 drops of Benzo at 50F:

Obsidian Aqua Pyro developer 1:500 30 minutes at 50f with 6 drops of Benzo. This is more of that very heat/age-fogged CFX 5538 film:

Dupont Superior 4 from 1963 in D78 and same film in diluted Xray developer (metol/hydroquinone) denoted with the 2 in the lower right corner. The x-ray developer has a bit more grain & contrast which is characteristic of using that in general. These were both chilled to 50f, 15 minutes 6 drops of Benzo:

So, in closing: Order up a few grams of Benzo from a supply house like ArtCraft Chemicals in NY or Photographers Formulary in Montana. 10 grams makes 1 liter of 1% solution. I measured 35 drops to a ml dropper. That’s 6 rolls roughly per ml. 1 Liter treats 6000 rolls. I got a great deal on a kilo of Benzo and doing the math that will treat 600,000 rolls (lol).

The benzo should be mixed with HOT (near boiling) distilled water. Use distilled as it will be around for a while and will get nasty if using average tap water. Lower the dev temp to 50-55f and add 50% more time than what may be called for that film from the Massive Developer Chart. You may well have to experiment a bit.

DON’T listen to people that tell you to throw old film away. The results here are more than acceptable for a used camera body/lens test or for casual street photography. Perfect for the beginner student who just doesn’t have the $80 to spend on fresh Tmax or even $40 for Ultrafine. There is a time and place for new film—any important events like weddings, births or a paid portrait session merits fresh film. This process helps to draw out the image while suppressing the fog. I can afford to share & give away old stock that I may have paid $5 per 100ft roll and the user can be happy with the results.

So far the ONLY film that has not benefited from this was some military surplus high-speed infrared from 1962—it was just too far gone.

About the Author

Daniel Keating is a photographer from Tucson, Arizona. He is a former technical support rep for Noritsu America Corp (1999-2004). Prior to that, he managed numerous photo labs from 1978-1999. He developed his first roll of film in 1972 as a junior high school student. He collects cameras and still shoots primarily on film. He develops it himself and makes his own color chemicals from scratch. You can see more of Daniel’s work on Flickr.

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19 responses to “How I removed base fog from old film stocks”

  1. Randy Hendrickson Avatar
    Randy Hendrickson

    Thanks for this. Do you think would be a good choice for some rolls of exposed (1950s) Pan film. I did one roll in Rodinal stand at 1:100 for an hour. I got images, but tons of fog. Also trying L110 with a roll of 2003 tri-x with unknown storage history. I chill down to around 60 degrees but still pretty grainy and foggier than I’d like.

    1. daniel keating Avatar
      daniel keating

      If you use rodinal, increase from 5ml a roll to 7ml a roll–go 2 hours in chilled juice down to 48-50f

    2. Soren Jahan Avatar
      Soren Jahan

      Nice to see you here, Randy! I’m about to start with Benzo myself…

  2. Anthony Maw Avatar
    Anthony Maw

    If I remember my photo chemistry correctly benzotriazone as an anti-fog agent works well but at the trade off of reduced the film speed.

    1. daniel keating Avatar
      daniel keating

      It’s a restrainer so it impacts dev activity and perceived speed. The normal 1 stop per decade still holds

  3. Jan Kunicki Avatar
    Jan Kunicki

    I regularly develop Agfa PankineK 50ASA exp. 1958 with FX-37 1+7 20C 8:00min with very good results.

  4. Lance Rothstein Avatar
    Lance Rothstein

    Thanks so much for this article! I also have 800ft of the CFX film and several others I’ll be trying this on for my Labeauratoire film shop. Cheers!

  5. Juan Avatar
    Juan

    Hello Daniel, thanks for the info. I wonder if this would work with HC-110, do you have any idea how much I should add to the developer to proceed?
    Thanks in advance!

    1. daniel keating Avatar
      daniel keating

      It all depends on the degree of base fog in the film. You may need 6 drops, you may need 12.

  6. alt.kafka Avatar
    alt.kafka

    What agitation are you using for these developers? Is it all stand development, or are you just doing that with the Rodinal? Thanks.

    1. daniel keating Avatar
      daniel keating

      reduced agitation–15 secs every 3 minutes on non-rodinal mixes

  7. Trey Green Avatar
    Trey Green

    Hi Daniel, thanks for the very detailed article. I have a few bulk rolls of film from the late 50s early 60s, most of it is Kodak Linograph Pan Safety Film. Likely improperly stored for who knows how long. It might be motion picture film, I’m not sure because I can’t find any info about it on the net. Would you suspect the guide you’ve laid out here would work to develop this film once it’s been exposed? I’m very new to developing film and film photography in general. I have only used d76 to develop b&w, but have rodinal and benzo being delivered soon. Coincidentally I am also Tucson based and found all of the rolls of film at an estate sale here in town. I’m not very optimistic, but I have 4 100ft rolls of the stuff, so I can afford to play around with it a bit. I also got a bulk roll of something called Anscochrome Daylight Balance film, which I believe is a color film stock, any advice on that? Thanks!

    1. daniel keating Avatar
      daniel keating

      Hi Trey,
      I acquired some linograph film that was army/AF surplus– they used it to test munitions/explosions at gunnery ranges but that was marked Shellburst Linograph film. I have used this method to develop film as far back as 1951 dated. The only film too far gone, so far, was some 1962 high speed infra red. The anscochrome will be transparency slide film. Here is an old article WITH formula tables a few pages in–good luck finding agents like “DA-7” –long gone https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7262840

      1. Trey Green Avatar
        Trey Green

        Thanks for the response, excited to give it a go.

  8. Fabio Avatar
    Fabio

    Hi,
    Interesting read. Would this work with C41 process as well? I have some very old Fuji motion picture stock which has havy base fog.
    Kind regards

    1. daniel keating Avatar
      daniel keating

      No, it will not. C41 is a processing standard and normally c41 is sold as a “kit” and a liter may cover 30 rolls of film. If you add a restrainer it’s toast. This treatment is only possible with black ^ white film and 1 shot developers

      1. Soren Jahan Avatar
        Soren Jahan

        I was wondering why this treatment only works with 1-shot developers? I’m used to developing with stock solutions and it would be great to just add a few extra drops after each round…

        1. daniel keating Avatar
          daniel keating

          NOPE–DO NOT USE in stock solutions!!! The restrainer will continue to work and will eventually kill your mix prematurely. ONE SHOTS ONLY!!

          1. Soren Jahan Avatar
            Soren Jahan

            oh damn, ok, good to know! thanks so much for replying and for this great article. time to give it a shot ;)