Summary: Sold my AF Nikkor 300f4 EDIF and was looking for a 300f2.8 lens when a friend notified me that a photography store on eBay was going out of business and selling Sigma long lenses for good prices so I bid $1825 and to my surprise I won the auction and received a Sigma USA waranteed lens. The lens is fast and sharp on my D2H and D700 and the f2.8 is invaluable even on a high iso camera such as the D700.
Pros: Fast and quiet and works quite well with Sigma's teleconverters.
Cons: Only weakness is the tripod collar could be a little longer like the one on the Sigma 120-300. My preference is for the center of gravity to be a little more towards the front rather than the rear of the lens.
Summary: Had to replace my 300 2.8 Nikon. The cost of a new Nikon was just a tad out of the question, at the time. I had used a 300 2.8 AF Sigma once before (on loan) and I was impressed with the reults. So I took a punt, while in London and purchased this lens, to be used mainly for soccer and baseball.
Pros: This lens is hitched to a Nikon D2X. The lens is light, but still needs a monpod. There was no evidence of it wanting to "hunt" in low light and it's auto focus was up to my expectations. I was really satisfied with the results, it produced in combination with the D2X. Yes. I would love another Nikon AFS 300 2.8 but the cost of such a lens is a bit disturbing and this Sigma is well up to the task, at present. Time will tell.
Cons: It comes with a drop in filter (Polariser), but there appears to be no other filters to fiit (you know..red, yellow etc). Maybe Sigma needs to work on this. I look after my gear, so I don't anticipate a problem with this lens. As I said before, only time will tell.
Conclusion: Jag hade lite problem att justera fokuset med min Canon 7d men när det väl var gjort kan jag bara säga wow vilken grym glugg och skärpan kan jag inte klaga på. Snabb som bara den missar nästan aldrig fokus. Jag kan handhålla den och få bra bilder om tid ej går under 1/640. Riktigt bra bildkvalitet med 1,4 telekonverter!