Several Questions after New York Trip

[derekjacoby]

I just got back from a trip to New York. One of the many reasons I was going was to get comfortable with my camera equipment before I go on the "real" trip, to Europe.

Canon XTi
EF-S 50mm f/1.8
EF-S 12-22mm f/3.5-4.5

I had a great time and took some ok pictures but I ended with two questions I wanted some advice on.

1) if I see a little piece of lint through the viewfinder and it stays in the exact same place (and size) when I change lenses AND it does not show up in the picture, that means that the lint is probably on the prism itself? (also, it's not on the viewfinder) If so, what's the best way to clean it?

2) I had difficulty capturing scenes with lots of contrast in lighting. For instance, Times Square at night. The camera had enough light to shoot just from the neon signs alone but when I looked at the pictures they were extremely dark (all you could see were just dim hints of the signs). The only way I could "solve" it on the fly was to dial the f stop way up and do a much longer exposure with a tripod. My question is: Is that the only way to get good, even lighting and color? Dialing up the fstop and using a much longer exposure.

I had the same problem taking shots in the Cloisters Museum, which has examples of Gothic Cathedrals.

I'm uploading the cathedral problem picture, Times Square with bad lighting, as mentioned, and Times Square with better lighting, as mentioned also.

Thank you all,
Derek