After switching over from Canon one of the compromises I had to make was to lose my Canon 300 f2.8 L IS, but to get the D3, it was worth it. Anyway, my longest lens at the moment is the 70-200 VR. The airshow season is starting again and I need a longer reach lens. I can't afford the Nikon 300 f2.8 VR and I truly believe the Nikon 300 F4 AFS will soon be replaced. The best compromised lens I have found is the Sigma 100-300 which with 1.4x converter would give me enough reach and the flexibility of a zoom. I would like to hear from those who have used this lens, particularly with the D3 and the 1.4x converter.
Ive not used this lens but did study its worth in the last few days. The f4 max aperture kinda killed it for me (DX shooter). Now then on a D3, you'll still realize the thin DOF but shooting air sports, with a TC, you're lookin at f5.6 at best. Course D3 will make up the shutter speed difference... might work well I guess. The lens is well reviewed all over the web wrt IQ but finish is with all sigma's a llittle lacking
