Hi Alan. Yes, I understand your point. Hopefully the combination of your comments and mine will help the OP to better understand when it makes sense to use the extender. The alternative is to use a sensor with denser pixels, e.g. R7 on base lens vs R5 with 1.4x extender offers equivalent pixels on the bird and in my experience, the R7 approach (specifically with the 200-800) typically gives slightly better results. Of course, much depends on AF performance and R5 II with extender may well outperform the R7 with bare lens (but I haven't, at least yet, sprung for an R5 II). But then, there will be an R7 II

. My real preference would be for an R5s that would provide the wider field of view AND the higher pixel density. 101 MP would be perfect (and you could capture a frame of 12k open gate video for full resolution)

.