Again, depending on your budget, I've had good results using the Magenta Multiview technology for transmitting video over cat 5e cabling.
While this technology still works perfectly well, I think it is more or less sunsetting as a "go-to" for video transmission with the nearly universal adoption of HDBase-T for 4K video over cat 6 cable.
When purchased new, these units were quite expensive ($800-$1000), but you can often find transmitters and receivers on ebay for pennies on the dollar. From my look this morning, you could probably score a transmitter and receiver for well under $100.
The entry
level units transmit and receive a
VGA signal over up to 500' of cat 5e cable. Other than a video camera itself, you will also need a convertor to change either a 480i
composite video or
HDMI video to
VGA. On the receiving end you just use a large computer
monitor with a
VGA input (and we all have some of those lying around...)
I used a Multiview 500A/S transmitter and Multiview 500A receiver in this capacity as a live
monitor for the organ
console at a large church in Minneapolis for about 3 years. I won't say there is no
latency in it (I'm guessing it's less than 10ms) but the organist never complained that it was a problem when accompanying choirs and orchestras via the
monitor.
Also, if you're using building data cabling, you'll obviously need access to the
switch room so that you can remove both data runs from the
switch and simply
jumper them together. That's what I did at the church and it worked just fine.
Here's the brochure of the Magenta Multiview product
line from a while back: