Better guesses for developing in Flic Film "Black, White & Green"

Dear community,

I really like the industrial incarnation of Patrick Gainer's PC-TEA developer that is Flic Film's Black, White & Green (BW&G hereafter) because it's very consistent and widely available in Canada.

However I also like trying new and/or exotic film, and Flic Film's suggestion for unknown dev times is to use "whats used for Kodak D-76 1:2." If you've been to the massive dev chart, you'll know that 1+2 is a seldom used dilution, so I made a more useful rule of thumb to calculate better starting points for BW&G development at the recommended dilution of 1+49. This was part of a much larger project to help the photographic community that is on hold for now, because a PhD in chemistry is plenty of work already.

So it happens that D-76 1+1 dev times can be correlated even more successfully with BW&G times such that if we take the D-76 1+1 time (in decimal in case of a not-round number of minutes), multiply it by 1.145 and add 0.32, we obtain a strong educated guess at the dev time in BW&G 1+49.

TL;DR (D76_1+1time * 1.145) + 0.32 yields a good starting point.

I have used this equation successfully to predict new development times for:

• Catlabs X 320 Pro, at 13:00
• Svema Foto 400, at 23:15 with great success
• Panatomic-X, at 10:30 also with great result but I mean this is Pan-X we're talking about-
• Lucky SHD400, at 12:30 (this one might need a bit of tweaking but now I realize it's not really a 400 ISO film)
• and thanks to this forum's very own @Andrew O'Neill Ferrania P33 (which came out a little thin at 13:00 because I couldn't indicate the agitation pattern of 10 seconds per minute, in time, See his video here ).

Thanks again Andy!

I hope this first post of mine helps those who enjoy BW&G to test it out with all sorts of films since D-76 has dev times for even very old films (although beware it's a developer that can promote fog on expired films). If I have it my way this won't be my last post as I have plans for what to do after I get my degree that may or may not involve reducing agents.

- Jason, the little ghost chilling in-between the grains of silver

P.S. If you're someone who sees what bigger project this could have been a part of, please get in touch and I'll do what I can to help create what I lack time for.

FWIW, the 1:2 designation is one of the alternate ways of referring to a dilution of one part stock plus two parts of dilutant (water usually)
The Kodak documentation often uses 1:2, while Ilford documentation uses 1 + 2, but they both mean the same thing.

Yes, thank you for the precision, I meant them as synonymous. It remains that for many niche films there are no published times for D-76 1+2 AKA 1:2 AKA 1/3.

FWIW, looking at the development times on the Flic Film chart, it looks to me that the D76 1+1 times for Kodak film don't track the same way as the same way that the times track on the Flic Film chart.

The Flic Film chart:


Kodak D-76 table - from the D-76 datasheet:

Note that the Flic film times for Tri-X are longer than Kodak's time for Tri-X, while the situation is reversed for TMax 100 and TMax 400.

Thank you for bringing this minor outlier to my attention. I appreciate that as a newcomer I have yet to establish any authority on the topics at play here so I'll attempt to give my interpretation of what we're seeing here.

First, I will trust Kodak's rigorous testing of their own film and developer over anything I see from any other company, as the combo of Tri-X and D-76 is decades old; saying it is tried and true would be quite the understatement. From that, what I don't know is how Flic Film's testing was done to obtain that one dev time. Could be precise sensitometry, could be ocular negative appreciation. While I don't have Tri-X on hand to test BW&G with it (and don't plan to acquire any during a trade war), it sounds plausible to me that the dev time on BW&G's datasheet comes from an estimation following a thin negative at a shorter dev time, and/or that from extra caution they lean on the latitude of the film as a fudge factor to make sure people don't underdevelop their Tri-X with their product. Who knows.

Second, as for the equation I provide in the OP, it was an aggregate fit of all the data I could verify as true regarding BW&G and other film's dev times in D-76 1+1. The result is this curve which correlates existing dev times by 97.9% (r²=0.9798) which is excellent, and to me suffices for the equation to be used as a good model of the BW&G dev times. So of course since it's not 100% there will be some variation and some dev times will be a little over or under but that's part of what I call a 'starting point'. The differing trend between Tmax and Tri-X could be the result of that +/- versus the curve, but I don't have much incentive to verify that manually, especially that these films are both well-known and have published times for both developers.

Third, to prove that it works in the real world I went further and tested it with films of various speeds and expiration dates and was most of the time spot-on, first try. Hopefully that demonstration proves that the pudding is in the... hmmm... fixer? (Nope, that fell apart.)

Anyway, I hope this might address most concerns that came up when looking at the data at a more surface level!

Cheers,

-Jason

Personally, I was wondering whether Flic Film's use of 1:2 was a typo!

Aaaaaahhhh, as in their own recommendation for dev time substitute, I see now! Hard to tell since there are so few times for this dilution... The whole thing is mysterious honestly hahahahah, and only appears on their website and not on the bottle itself if I'm not mistaken. ¯\_(ツ)_/¯ eh