There’s a lot of answers, solutions and possible ways to address the post on this thread.
I still use old, tried and true equipment for dual-camera switching at gigs calling for this, or sometimes to save me time in post.
I use 100′ Canare RG59 flexible coax cable with BNC and/or BNC to RCA pin plug adapters, a V/A distribution amplifier for runs longer than 100′, and an old but still wonderfully functionable Panasonic MX-12 mixer with no appreciable loss in video or audio quality. It is a personal preference to not go longer than 100′ without utilizing a DA to keep the signals sweet, but as some have pointed out, longer runs often work.
I have also used the S-Video connections between camera, mixer and end source (editing system, computer hard drive, projector or DVD recorder) for runs of 75′ to 100′. There can be some latency issues between the video and audio, using either type of cable, but nothing I cannot deal with provided my audio cable isn’t significantly longer than my video cable.
