I currently have two GL2's that I use for weddings, shorts, home movies, and general videography. I am beginning to do some surveillance work that requires very low light videography. Dark streets, night time, very poor lighting etc. Image quality is secondary. People have to be recognizable but nobody is going to care about a bit of grain or poor color balance in this work. So I'm considering dumping one or both of my GL2s if I can get into a camera that is significantly more sensitive. I haven't been watching the market. I don't know what I might get for the two GL2's but I'm considering selling one and replacing it. I can't sell both and get a single video camera; I need/want a backup in the event one fails, so the replacement would have to be around the cost of a used (ex. condition) GL2. This isn't a troll for a sale. I haven't made my mind. Any recommendation on a good low-light camera (with a reasonably good optical tele?).

You might want to check out the Panasonic AG-DVC30. It can record in zero lux in B/W, for not for very far away, further distances require infared light source which might be noticable. I'm not sure what the Sony Camp offers. I think they might have some models that have a green type of no-light image, I'm not sure. For light sensitivity, generally the larger the CCDs, and the lower density the better.

http://panasonic.biz/sav/dvc30/index.html

Check the Sony VX2100.

Alternatively look into some with IR capability. There is a nitch market for surveillance cameras that you may want to investigate. They are optimized for that purpose, and not for normal event videography. Check with security device suppliers.

If grain is not an issue, try using additional gain in post with the GL2 to see how it looks to you.