Tamron, Sigma Lens

[Beachduffer]

 I'm looking for the pros and cons on both the -  Tamron (considering -18-270mm) and Sigma (Considering 18-250mm) lens. i.e. glass quality, workmanship, etc. Would be used on a Canon EOS 50D.
thank you   

[Bob Atkins]

It's hard to say.

The Tamron 18-270/3.5-6.3 VC is a little longer, but the Sigma 18-250/3.5-6.3 OS has an HSM AF motor. Pricewise there's very little difference since the Tamron has a $50 rebate, making the final price only about $20 more than the Sigma.

Qualitywise it's probably a toss up. All such wide range telephoto zooms have to make some optical compromises to keep size, weight and cost down.

Personally, on the basis of past experience, I'd probably go for the Tamron.

Over on my LensPlay website a lens defect survey indicates that 22% of Sigma owners report some sort of problem, whle 15% of Tamron owners report a problem. For comparison only 7% of Canon lens owners report a problem. Make of that what you will!