Cheers, quite tempted to try the 500 canon and maybe x2 extender for further reach when needed...
A 600mm/f4 is a better match on full frame. With a 1.4x TC it's also a bit more flexible than 800mm/f5.6.
Not so sure. I used to have the Canon 600 F4 L IS (+ extenders) but I find the Canon 800 F5.6 L IS to be a significantly better lens on FF crop and film.
Now the Canon 600 F4 L IS Mk2 is a different story as it is quite a bit lighter and works better with extenders - but it is also double the price that I paid for my 800 mm. Bit of a no brainer really? Also I don't find 600mm long enough for much of what I do so buying a lens at double the price and then having to use an extender is not quite so attractive to me.
Just my experiences.
Maybe I interpreted the subject as "if you only could have one long lens".:smoke: and If I had an 800mm I would have to get something shorter as well (I see you have). 300mm+800mm would be nice combo, but not cheap..:eek!:
Anyway, my main point was (probably) to get something significantly longer and faster than the TS's current 100-400/5.6mm zoom. That would be 600/4 on FF. 500mm would be a bit short IMO.
But if getting a completely new setup today I might even go for one of the new "lightweight" 500/4mm + a good APS-C camera. Sigma 500/4mm Sports + a D500 would probably be the best bang for the buck. But I don't think TS will drop Canon (1DX) for sigma/nikon...:-O
Thanks folks, I’ve managed to buy a really nice condition canon 500mm f4 looking forward to getting to use it!