Hi I'll be shooting some bw 35 mm Tmax in FEB I am visiting a place with temperatures falling up to 0 degree celsius. I intent to pull TMAX 100 asa film up to 2 stops as the landscape will partially be covered with snow.

I wanna know if the responce of the film is affected due to considerable extent at such low temp? what kinda comphensations one can make to overcome those. thanks shreepad

-- shreepad (middlegray@hotmail.com), November 28, 2000

Answers

You think 0 dgrees C is cold? Where do you live. Some of us would think of that as a warm winter day. You can work outdoors in a T-shirt and shorts at 0C.

Cold won't affect film speed. If you get it really cold (-80C) it will lessen reciprocity failure and maybe break when you try to wind it, but that's about it.

Just because there's snow doesn't mean you'll have to pull TMX, but you might if you have deep shadows. If you're thinking of an N-2 development, I'm not sure you can actually get that much contraction with TMX can you?

-- Bob Atkins (bobatkins@hotmail.com), November 28, 2000.

Being that winter is the time for static, before you go out (or load film in your camera), wipe the inside of your camera with a good anti static cloth and then blow it out with canned air. DO NOT use motor drive or winder if at all possible or you run the risk of "lightening" marks on your film due to the static discharges when transported rapidly. Be also aware of condensation. If you are going in and out of a warm building, try to keep the camera either cold (leave it out in a "Army Ammo case" or something that is somewhat protected) or keep it in your coat until you are ready to shoot. Without a doubt, get a good UV or skylight filter. Cheers

-- Scott Walton (scotlynn@shore.net), November 28, 2000.

Tmx will pull to N-2 if you give it the proper increase in exposure and the proper decrease in development time and agitation with the right developer. James

-- james (james_mickelson@hotmail.com), November 28, 2000.

Thanks for those suggestions The only thing I did'nt get is the concentration bob is talking about Bob please can you put more light on that?

Ok I might have sounded that I am pulling TMX just because there is snow around, Actually I have been doing that for a better grain quality as well, The equaction is : TMX 100 pulles to 25 ASA, in D76, 1:1, 6.5 min @18degrees c

BTW, Bob I live in INDIA! thanks

-- shreepad (middlegray@hotmail.com), November 28, 2000.

0 degrees C is not cold enough to require any special attention, believe me. ;)

The only thing you must watch is snow: if there is a lot of snow on the ground, it will cause your meter to think the image is brighter than it is, resulting in underexposure.

I've shot at temperatures approaching -30 C without major problems (although batteries get very fussy at those temperatures).

-- Jim MacKenzie (photojim@yahoo.com), November 30, 2000.

Contraction is taking a wide range of light levels ("a lot of zones") and conracting (not concentrating) them down to fit on the film by a combination of increased exposure and reduced development. See any zone system text (e.g. The Negative by Ansel Adams) for details.

Most modern 35mm films will be OK with N-1 (a 1 stop conraction), some might just make it to N-2 (a 2 stop contraction).

-- Bob atkins (bobatkins@hotmail.com), November 30, 2000.

Out of curiosity, does anyone know at what temperature cold does become relevant? I've seen "cold cameras" that had compartments for dry ice, and I believe the purpose was to increase the EI of the film. I haven't heard much about this technique since the 1970s.

-- David Goldfarb (dgoldfarb@barnard.edu), December 03, 2000.

Cold cameras don't really increase EI, they just decrease reciprocity failure, so at very long exposure times (often hours) the effective film speed goes up. At normal exposure times (1 second or less) there is no effect. Cold cameras were used for astrophotography, but these days it's mostly done with CCDs, not film.

-- Bob Atkins (bobatkins@hotmail.com), December 04, 2000.

Gas hypering is a more common method to increase film sensitivity for long exposures. You can buy gas-hypered Tech Pan from some suppliers.

-- Jim MacKenzie (photojim@yahoo.com), December 05, 2000.