Nikon Lens over Sigma or Tamron

At that level of lens, even modest differences in quality carry large costs. You would notice the difference between the Nikon and the other two in three areas:

1) Physical build. The Nikkor is a tank, and pretty well weather sealed. Someone like you out in a grubby environment like that will probably appreciate that more than, say, someone shooting indoor gynmastics most of the time.

2) Wide-open behavior. By the time you're into the poorer light, and are likely getting into 200mm, f/2.8 areas, you'll be glad for the Nikkor's stellar behavior at that wide aperture. Still very good into the corners, and still nice and contrasty. Speaking of contrasty:

3) Coatings, glass, etc... not picking on Sigma or Tamron, here, but Nikon's simply putting more $ into the materials and coatings on what is essentially one of their flagship pro lenses. No corners being cut, and they don't really care what it ends up costing. Sigma and Tamron are, by definition, making their versions of such lenses specifically to pursue more modest budgets.

Mind you, I really like all three Sigma lenses that I regularly use. I chose their 50/1.4 over Nikon's without even a consideration of the price - I just like it better. But it's Nikon's 70-200/2.8 for me, and never a look back.

Thanks so much for quick reply

You could buy a used Sigma, try it, and resell if it didn't work for you. That could save you some big money if it worked out, and you'd be out very little (if any) if it didn't. NOW is the time to buy used lenses from e Bay as prices are at a low ebb. Later in the year, when the weather warms, you could likely sell it for a tad more than you paid. Your risk is very slight as long as lens isn't damaged. I do this sort of thing often. BTW, I use the Nikon 70-200mm f2.8 VR-1 on my D300, and it works fine. I photo moving trains.

Kent in SD

Please see this thread from last month: http://photo.net/nikon-camera-forum/00Zt2e

It is a matter of whether you can afford the Nikon version and are willing to pay a lot more for some small improvements.

Mark, I am not sure where in the world you are located and if rental is a possibility, but at the price of the Nikon, it would be worth while to rent it and try it before buying. Only you know if you need the Nikon.

At the price of the lenses and your type of photography, I strongly recommend "all hazards" insurance on your camera equipment.

thanks for all the resonces
One thing no one has talked about is there a difrence in the speed of the auto focus?

I never tested the Sigma's AF speed for a careful comparison, but when I used it indoors on my D700 during a speech, AF speed and accuracy seemed ok. I didn't try it during any sports event, though.

Mark
I use a Sigma 120-300 f/2.8 to shoot sports with (equestrian events) and while they may not move as fast as cars its not like they are standing still. I have had no problems with the Sigma keeping up with them.
I live just outside of Daytona and keep trying to get over to shoot the races but they always seem to fall on the same days as my work..

I own the Tamron 70-200 and it's very sharp, a great lens for portraits and for basic things like a speech or news conference. But I can't use it when I shoot figure skating because it simply doesn't autofocus fast enough. Figure skating is tough becuase it's kids moving 40 mph under so-so light at best and virtually in the dark during some of the theater on ice skating shows. I've shot figure skating with the Nikon 80-200, the 70-200 VRI and the 70-200 VRII. Each is progressively better at AF than its predecessor. I currently rent the VRII for all my figure skating work and will eventually buy one. If you're going to shoot sports you absolutely need the VRII. Especially under low light situations. Haven't tried the Sigma but the current Signma new is only a couple of hundred dollars less than a used VRII and I would take even a used VRII over any of the others.