I think this is the less expensive one. Sigma let Tamron get a huge jump on them, although I wonder which is better at 600mm.
If the Sigma fires 100% of the time than the jump that tamron had is a moot point.
If the Sigma fires 100% of the time than the jump that tamron had is a moot point.
My Tamzooka autofocuses 99.95% of the time. Literally. Even my Nikon primes hiccup once in a very great while on my D7100.
Anyway, the early reports seem to indicate that the Sigma is a very nice lens. It will be interesting to see how the two lenses compare as we get more data. At nearly double the price of the Tammy, the Sigma will have to be significantly better to compete well with the Tamron, IMO. I think there will be plenty of people interested in how it compares with the newish Nikon 80-400, as well. It's great for photographers that we are getting this many solid options!
I can't say my Tam fails but there are some issues that range from annoying to not very good at all.
The focus freeze is a minor problem and unless you're a paparazzi or shoot other rarities for a living, not something life-threatening.
The inconsistent focus is another thing. If it is caused by the VR, it is easily fixed for fast shooting; disable. It's of no use anyways at higher shutters. If it does the same during slow shooting, that's more problematic since at 600mm handheld without VR, the amount of good shots at slow shutters decreases rapidly the more the shutter goes down.
Worst case scenario I'll do without VR entirely. I did buy it for the 600mm, not the VR.
The Sig is new on the market so time will tell how much more reliable it is.
If the cause is something else then it's good I got a 5 year warranty. That should give them the time needed to fix it.
J-See, I never have the focus problems you are encountering. I think you should return the lens for a new one. There must be something wrong with your copy.
Rob Bye has/had both, I think he stayed with the Sigma, he shoots sports with it very successfully.
http://nikonites.com/telephoto/26862-sigma-150-600-customers-hands-3.html#post381983