- A highly versatile focal length for nature photography - notably wildlife, large birds, wildflowers and telephoto landscapes. It's fills a key gap for me between my medium telephoto and super-telephoto lenses.
- Fast aperture is great for shooting in low light, or for achieving smooth backgrounds because of the shallow depth of field when wide open.
- Very sharp (I used it routinely with 1.4x and 2x Canon extenders and the results were still razor sharp).
- Moderate AF and OS performance (in comparison to the Canon 200-400mm lens, which costs about 3x the price).
- The lens is fairly heavy, as expected for an f/ 2.8 telephoto. Carrying it around helped beef up my biceps!
- Great value for a lens of this speed/focal length. At 1/3 the price of the Canon 200-400mm f/4, I consider the Sigma to be the affordable alternative in this focal range.
To summarize, I've found the Sigma 120-300 to be an excellent value lens and have used it to produce many pro-quality images. I love the versatile focal range, especially when paired with a 1.4x extender. It's not inexpensive (at just under $4000 CDN) but that's a bargain for a lens with this focal range and speed. Thumbs up from me - I routinely recommend this lens to nature photographers looking for a fast lens in this focal range.