Are lenses by the independent makers as good as those by the camera makers?
"Often, yes. Over the years we've seen many examples where the lenses from the top three independents -- Sigma,
Tamron, Tokina -- perform on a par with equivalent lenses from the camera makers, and occasionally even better.
For instance, we recently tested the Sigma 18-200mm f/3.5-6.3 DC OS AF zoom, which performed optically a notch better than
Nikon's 18-200mm f/3.5-5.6G DX Nikkor VR AF-S ($700, street) and about on a par with Canon's most comparable zoom, the
28-300mm f/3.5-5.6L IS USM ($2,200, street). The
image stabilization of the three lenses was competitive (Canon and Sigma, 2-3 stops' advantage; Nikon, 3-4 stops'). The Sigma, at $549 (street), costs $130 less than the Nikon and $1,650 less than the Canon.
Of course, like the camera makers, the independents have multiple lens lines, and their premium-grade optics can be nearly as expensive as the camera makers' top glass. Similarly, kit lenses and other inexpensive zooms from camera makers can challenge the independents on both price and quality.
Sigma offers a number of less expensive alternatives, and they do not equate to lower quality and image features. At times getting the Sigma is well worth the money, particullarly a Sigma with the EX designation. EX lenses have a propensity to encompass great build and image features. Sigma is also reknown for it's standard primes such as the 30mm and 50mm lenses. In certain focal lengths like in the 100-500mm series, Sigma has an illustrious collection featuring affordable prices and engineering not found in Canon or Nikon lenses.nearly all Sigma lenses are manufactured in mounts for
Pentax and of