I suppose somewhere in the corner of my mind the way I conceptualize things the higher pixel count of lets say the D600 or 800 would allow more clarity.. but that's my twisted chunk of grey matter.
I used the 100% crop for the purpose of this discussion. I wanted to emphasize my concerns.
I have a 1.4 TC that I have but I wanted to nail down the mechanics of this lens before I added another factor. I obviously have a long learning curve ahead.
I'll play with the F stop and ISO a bit... In my mind that's where I was also headed and hearing it just reaffirms my initial thoughts other than FX vs DX
The other consideration is this. Tri-pod and a Gimbal. I've got a pretty stout manfrotto I could put a gimbal head on but I chose this 500mm as it seemed to lend a hand towards acceptable handhelds over the heavier 400 and 600mm lens. I'm not overly excited about lugging a tri-pod around with a heavy gimbal on it. (unless someone could recommends a reasonably priced head that would suffice)
I'm feeling a bit better hearing that the lens is fantastic and the issues are me.