@CardiffOTT Thanks and yeah, it’s that fine line between the extra reach and the drop in quality; the MF 800mm is a real challenge to focus with the 1.4 on top but I’ll persevere...
Air France B777 F-GSQV 7 miles above Surrey on the way to LAX (hey @CardiffOTT I’m having a go at trying to emulate your excellent over the top photos using my D500 and my Nikkor 800mm f5.6 AI-S lens - hope you approve!)