Hi, today I went out and photographed a friend of mine. I loaded up some tri-x. We went out to the designed place. I put a grey card to the side of his face and metered. Then I spot metered the middle of his left cheek - he is Japanese, a little dark - meter said half a stop difference - and I started shooting. The day was very overcast, almost "grey". Which curve do I pick? (See attached image). I thought, since the day was so overcast, I can probably go to 9 minutes and not blow any highlight. Correct? Thanks.