8 out of 10 points and recommendedFull-frame useable, low distortion, well-controlled flareLacks sharpness at wide apertures, variable maximum aperture, limited filtration options
This is an amazing zoom in that it brings the 12mm focal length to 35mm film and full-frame digital, without the distortion one might expect in such an extreme focal length. The lens features Sigma's sound EX finish & construction; solid and only moderately bulky.reviewed October 29th, 2005 (purchased for $550)
The lens is at its best around f8, as it loses sharpness wide open. It also has remarkably well-controlled flare, important in such a wide lens. Shooting into a full sun produces a string of small, colorful flare spots that I've used many times to accentuate my compositions.
Unlike most competing ultra-wide zooms -- all of which are limited to APS-C sized digital sensors -- the Sigma 12-24 has a variable maximum aperture of f4.5-5.6 rather than the constant f4 of the digital-only zooms. With its built-in petal hood, the Sigma can only mount filters with the aid of the two-piece lens cap, which doubles as an 82mm filter adapter. In this configuration, vignetting occurs as early as 21-22mm. A rear filter mount for gels allows limited filtration at wider focal lengths.
If you do any full-frame work (film or digital) I would recommend this lens highly over the competition. You can produce amazing photos at a true 12mm focal length and it provides highly effective wide zoom capability for DSLRs with smaller sensors.
9 out of 10 points and recommendedSharp, constant f2.8 aperture, great zoom rangeNot as contrasty as you'd expect from a pro zoom
Sigma scores another coup with a unique lens unavailable from any other manufacturer. The 120-300/f2.8 is a real gem for sports photographers, as it combines the advantages of the traditional staples of sports photography: the 80-200 and 300 f2.8 lenses.reviewed September 4th, 2006 (purchased for $1,800)
My sample's lens mount worked itself loose in the middle of a shoot after just a few weeks' use. A small screwdriver now packs with all my gear for simple but annoying repairs of this occasionally recurring problem.
Also works quite well with Sigma's 1.4x teleconverter.
8 out of 10 points and recommended24mm at the wide end, fast constant aperture60mm at the long end
Serviceable pro-quality lens that handily goes to 24mm. There are better choices in this price range for a fast normal zoom (I compared this lens extensively to the Tamron 28-75 before deciding to keep the latter).reviewed September 4th, 2006 (purchased for $350)
Typical good build quality for a Sigma EX lens, smaller than average size for this type of lens.
9 out of 10 points and recommendedWide, fast, sharpNo AF
Even without considering how inexpensive this lens is, it is a very good ultra-wide prime. Consider the cost and it is an exceptional value.reviewed April 6th, 2014 (purchased for $300)
10 out of 10 points and recommendedPerfect lens for sports photographyNone
This lens is a significant improvement over the previous versions and well worth the upgrade. I concur with the findings of the review here, and add that the AF operation can be improved significantly with use of the USB dock.reviewed April 6th, 2014 (purchased for $3,500)
While Sigma has made many improvements here, the lens mount is still a bit of a weak point - there is a fair amount of play when mounted to my Nikons, and I'm concerned that this will become an issue over time (in eight years of use, my original version of this lens required two lens mount replacements).
See my complete, ongoing review of this lens here: http://sportsphotoguy.com/sigma-120-300mm-f2-8-dg-os-hsm-s/