Hi again naturegirl,
That's cool, I use the Nikon 200-500 too for everything with the d500, but I think the Sigma might be as good or better, jury is still out on that. I know the Tamron isn't as good as the Nikon IMO. The newer Sigma Sport looks good so far but you're right it is very heavy. I tried it at Delray Camera. Great for a tripod though?
Kit
Rockitglider
AKA: Kit O.
Nature Photographer, Model rocket builder, designer and flyer
Remote Control Gliders & Rocket powered Gliders as a hobby,
AUTOCAD engineer professionally for Fire Alarm Systems in Ft. Lauderdale Itnl. Airport (FLL) & PBIA as well.
Website:
http://img.gg/a7WNYUF