I am going to Las Vegas and would like to get some of the more popular photos taken with a solid back round and the traffic moving with respect to the traffic being blurred. I know I have to leave the shutter open for about 30 seconds and use a tripod..or maybe not. I would like some feedback or tips on AE or shutter speed, ISO settings etc. Specfics would be great. Like shutter speed f4 w/ ISO 400 you get the gist.