if i'm able, planning a road trip the the eclipse totality zone in august. want to get some good pix and perhaps video of the event. i have a nikon d7100 and a d610 for bodies. i have an older f4 400mm totally manual lens and a f2.8 D model 300mm. for the 400 i bought one of those nifty 1.6 extenders with the auto focus, works great with the old 400, in fact makes it a 640. now i need solar eclipse filters, don't have to be super high dollar because this will be their only use. preferences? suggestions? for the filters. i have 2 gimble tripod mounts and good sturdy tripods. the lenses are nikon