Video was used, and I don't doubt still is. Hopefully they have new equipment because when I delt with it it was called Pilot Landing Aid Television (PLAT) and it was a Sony 3/4" black and white system with a couple cameras (I think one at the angle and another by the LSO platform or across from the platform) The pictures were pretty poor, there was only one system for each boat and occasionally somebody would destroy it with a few tons of a/c.
Sometines on television up next to the humidity channel you will see some obscure history video etc with really poor looking black and white footage in it on a U.S.N. carrier...that was probably from the PLAT. There is footage of the flight deck explosion on Forrestal from the PLAT in the public domain, very scareifying.