I'll be using a lot of Portra 160NC next week. I'm just looking for tips to get the best from the film. Doing a little research (albeit on the Internet) I've read that it's well known to expose it at ISO100 for good results - Any thought on this or is it wise just to rate it as the box says at ISO160? Also, I was wondering how well the film would fair pushed to ISO400 or even ISO800 and how skin-tones and whites would look pushed that far. I've seen some examples of it pushed to 1600 and it looks a little 'cross-processed-like', but not too bad. I'm having trouble finding somewhere that has the 400NC or 400VC in stock in time so to save any hassle it would be good to know it can be pushed to 400 pretty well.. Any sample images would be appreciated. Thanks. (I will have time to experiment beforehand but it's good to get some prior advice/suggestions as well).