One of those last second questions people ask just before they run out the door to catch the plane, I presume.
Since you asked this question 1 hour and 40 minutes ago, I'm guessing Pooky's the only answer you MIGHT have read before you left.
I hope not but it's painfully obvious that waiting to the last minute or asking on a moment of spontaneity will rarely get a satisfactory response.
I imagine that you are referring to the outside color of your SLR when you referred to the luminance (Black and White)... as I recall, no-one has ever made a Black and White SLR but maybe you own something quite rare.
The film ISO is not all that important... you can achieve the same results with a faster film as with a slower one. The purpose of your shooting in the snow should determine the film speed (sports would certainly favor a faster/higher ISO than landscape photography).
The important thing is to realize that your meter does what it's supposed to do (NOT fool the camera as Pooky suggests). It meters for 18% average lighting and a good photographer will realize that and expose accordingly. The meter wants things to be 'average' and snow, not being average will look like a neutral shade of gray if shot at the recommended setting given.
As a photographer, you should recognize this extreme in luminance and compensate either by over exposing (setting your exposure compensation to be 1.3 to 1.7 with Nikon or 1.5 to 2.0 with most others) to make up for the luminescence of the snow.
I would also recommend a polarizer as snow has reflectance that you may want to control too.
Film type?... without knowing your purpose, how could I suggest a type?
Good shooting.
~Galan (google me as G.Alan Fink).
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