One further step......
I originally posted under connection issues - it's been seen but nobody appears to have an answer, but I am a little further on...... I have a Sony TRV60E connected to my iMac via the firewire 800 port. (I originally tried the Thunderbolt port via an adaptor. The adaptor was recognised, but the camera didn't show.) The camera can now be seen when looking at the Firewire device tree, but it will not connect with any program on the Mac. Admittedly I only have Quicktime and Sony's own Play Movies home, but the camera does not show in finder either. I am running High Sierra 10.13.6 and this Mac will not support any further updates; iMovies will only run on Mojave and higher.
The camera dates from 2004, the Mac will not run the USB driver software provided with it, referring to it as unsupported, AKA too old.....
Does anyone know if there is a way to have this camera connect??
iMac 21.5″, macOS 10.13