Canon Lenses Vs Sigma Lenses
Canon lenses vs. Sigma or Tamron?

How do Sigma and Tamron compare in quality to Canon L series lenses? Do you sacrifice quality to save a buck? I have heard the glass is not as good on the off brands.

3rd party brands such as Sigma and Tamron make very good products, just not as good as Canon.
When you compare two similar lenses, say a 70-200 f/2.8 the build quality is immediately and unquestionably noticeable. Canon makes tanks for lenses. the 3rd party brands won’t take wear and tear as well as Canon glass. The optics are different inside each lens, but i’m not very knowlegeable on that topic.

Canon Lenses Vs Sigma Lenses

Canon vs Sigma lens, whats the difference?

Canon EF 70-200mm F2.8 L USM
Sigma APO 70-200mm F2.8 EX DG II HSM

The short version, IMHO, is the Canon is better. I tried several copies of the Sigma along side copies of Canon’s 70-200mm f2.8L USM and 70-200mm f2.8L IS USM. Ultimately I stuck with Canon because of build/image quality.

The Sigma is certainly cheaper than the Canon lens and it’s not as conspicuous because it’s not a big white tube. However, the Sigma is not quite as sharp and not as fast with respect to autofocus. The Sigma also seemed to be more prone to flare than the Canon. More than once, I’ve noticed Sigma that cast a funky “yellow” hue to images and this Sigma was no exception. Furthermore, all of Canon’s L-series 70-200mm lenses offer environmental sealing/gaskets to keep rain and dust out of the camera and the lens.

If you have a tight budget and need f2.8, try several Sigmas and pick the one that’s sharpest. If you need a sharp lens that offers environmental sealing and money isn’t a problem, go for the Canon. I ultimately chose the 70-200mm f2.8L IS USM and despite the substantial cost, I don’t regret it.

canon ultrasonic 70-200mm lens