Currently am covered at 400mm (trusty 400/5.6 ED-AI), but occasionally need something longer for my long-distance landscape shots that are my thing to do. Looking for something around 600mm. My 400/5.6 is just too slow many times when used with the TC (need to stop it down 1 stop usually to get to excellent sharpness), so the 600/5.6 ED comes to mind. The 500P+TC is an option, but it's getting a bit too long at 700mm perhaps, but if the IQ is good I can live with that.
So, any opinions on the 600/5.6 ED vs. 500P+1.4TC? I'd primarily use both stopped down to f/8 for the most part, but also, when the light gets dim f/5.6 is likely to be used.
And, just to cut off the argument, I know that atmospherics can very much limit the sharpness of a long tele, but for my locations and what I shoot, many times during the spring and fall (and winter) it's not a big factor: Reach & light gathering & flare/ghosting resistance are also very important as well as sharpness. CA, if removable in post is just fine.
Thanks for any info!
- John