OK, next question: I have come into a large stock of old, old film. Some has been refridgerated (some since the 50s!) and some not. As such, I am anticipating varying degrees of base fog. Now, be it for paper or film, I have never dealt with defogging issues. I note Kodak products termed anti-fog, and a number (#1, #2, #3, #4) designation. I know some of these are discontinued, but I am curious at teh differences. I note their use is always cited for photo paper, not film.... is this always the case? To reduce film fog would I simply use a reducer instead, after the fact? This forum was SOOO helpful with my last question, I await my upcoming antifog education with enthusiastic anticipation! ;-)

Thanks! --Doc.

-- Edward Haigh (drcocktail@bigfoot.com), November 21, 2001

Answers

I noticed that no one has responded to this question. Not that I have an "answer," but perhaps some information. I have never used an antifoggant with film, but it can be done. The tradeoff is rapid speed loss, so you would have to do tests to determine your effective film speed.

Anti-fog #1 is benzotriazole, typically used in a 1% solution (sometimes dissolved in ethylene glycol), and, in my experience, most often used as an additive to paper developers.

Anti-fog #2 is 6-nitrobenzimidazole nitrate, usually used in a .5% solution, often in astrophotographic and reversal processing applications for film.

I'd go with the #2 and run some tests before shooting anything important with old film. Maybe someone else can tell you how much you should add per liter of developer working solution. I found a URL describing its use as a pre-bath for 8mm movie film: http://8mm.filmshooting.com/the_lab/g3steps.php.

-- Ed Buffaloe (edb@unblinkingeye.com), November 29, 2001.

I've been studiously doing my own research on the subject since I first posted the query, and in the interests of knowledge disemmination, I'll give you what I found. I now have acquired some Edwal Liquid Orthazite - which is a compound of benzotriazole, sodium sulfite, & water. While it DOES mainly spec for photo paper, there is this line at the bottom of the back label: The addition of 2ml per gallon of D-76 or similar borax-type developers will give finer grain with no apparent loss of film speed. The folks @ Freestyle who sold it to me advised that perhaps a tad more would work the magic I desire, which is still a LOT less than Edwal suggests for paper de-fogging. It seems like Kodak anti-fog #1 (benzotriazole) may still be made, but the sources I could find were all out of the country. I wonder why? Seems like it's used mostly for X-ray/tech and motion picture purposes these days. I'd like to get some; price-wise the Edwal Orthazite is quite dear. Beyond this, I found some VERY interesting weblinks treating the subject, one of which even appears in Greenspun/LUSENET. Check 'em out.... more commentary remains welcome. Here they are:

http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id= 004EHP

http://palimpsest.stanford.edu/byform/mailing-lists/cdl/1998/135 3.html

http://groups.yahoo.com/group/photoforum/message/7157

-- Edward Haigh (drcocktail@bigfoot.com), November 29, 2001.

Photographer's formulary: http://www.photoformulary.com/ sells Benzotriazole in various sized packages, including 10g for $4.44

-- Ron Gratz (rkgratz@mtu.edu), November 29, 2001.

Thanks, Ron. Madscientistville, here I come!

;-) --Doc.

-- Edward Haigh (drcocktail@bigfoot.com), November 29, 2001.