Yet another awesome lens by Sigma! I have yet to try it out outdoors but my tests from indoors are very promising! As always, Walmart has the best prices and service!!

Yes, I would recommend this to a friend

Clear Optics; Easy To Use; Firm Mount; Strong Construction

Slightly slow focusing

This is the best telephoto zoom lens for Canon for that money. I compare it with 100-400 and 70-200 Canon's and Sigma won at 200mm. It is sharper both of them. Colors little bit different but fine. Bokeh better on Canons 70-200 only at F2.8. But Sigma sharper and better results handhold.

Durable; Sharp Focus; Strong Construction

Heavy

I have owned this lens since July 2008. I use it for Pow-Wows, nature shots, wildlife. Its a great lens, very well built....I've dropped it from about 3 feet up and it hit the sidewalk, I thought I would be picking up pieces, but afterwards it works just like new.

Durable; Easily Interchangeable; Quick Focus; Rugged; Sharp Focus; Strong Construction

Heavy

After reading many, many reviews of the Sigma 120-400mm lens and the Canon alternative, 100-400mm and taking into consideration the cost, I decided on the Sigma lens. If I was wealthier, or a professional, my decision may have gone the other way.

Durable; Easily Interchangeable; Strong Construction

Heavy

I have owned this lens for about a year now. I am very pleased with the images I get from it. I have found it hunts whilst focusing in grass or trees. I tend to use manual focus 10% of the time because of this slight problem. I would not say it is a fault.

BEAUTIFUL LENSE, WORKS PERFECT FROM 300MM AND BELOW A LITTLE SOFT FROM 300-400 .. FAST AUTO FOCUS EXTREMELY SHARP, A BIT HEAVY, BUT IST A BIG LENSE (EXPECTED) ZOOM RING IS KIND OF HARD WHEN ZOOMING OUT( COMPARED TO NIKON LENSES)..

I bought this lens for outdoor sports photography with my Nikon D7000 (The seller changed over the attachment to a Nikon one). Brilliant lens. The price is phenomenal compared to canon or nikon branded lenses of the same calibre.

A definite step up from Canon 70-300 IS USM only if you are comfortable with the two extra pounds. If you don't have at least a good monopod, you will need one. I can, however, get useable hand held shots at 120th of a second at 400mm with optical stabilization on.

I do not currently plan to create a full text review for the Sigma 120-400mm f/4.5-5.6 DG OS HSM Lens, but the full array of standardized tests are available for your own evaluation and comparison with similar lenses.