Showing the Versatility of the 24-70 range on a full frame cameraThere is a reason every major Manufacturer has a version or two of the 24-70 f/2.8 lens.  24-70 is an incredibly useful focal length on full frame cameras. Wide enough to capture beautiful landscapes, starry night skies, cliche shots and everything in between. Above 50mm and at f/2.8 it becomes a fantastic portrait lens where you can really separate your subject from the background. If you want an incredibly versatile lens the 24-70 f/2.8 is one of the best options on a full frame camera- but they are typically expensive - Nikon and Canon offer options that cost around $1700-$1800. If you want a stabilized lens - Nikon’s lens is $2400 and Canon offers nothing at f/2.8 and stabilized.Sigma 24-70mm f/2.8 DG OS HSM ArtTamron SP 24-70mm f/2.8 Di VC USD G2Canon EF 24-70mm f/2.8L II USMNikon 24-70 f/2.8 VRSony FE 24-70mm f/2.8 GMThis is the Sigma 24-70 ART it offers a 24-70 with a constant f/2.8 and OS, sigmas version of image stabilization. You have an AF, MF switch with MO Manual override and it's currently on sale at B&H and includes the USB dock used for fine tuning and adjustments. The front filter is 82mm.  Overall build quality continues that ART line - it feels excellent in the hand with a nice finish. PROS
But what about that Tamron SP 24-70mm f/2.8 Di VC USD G2?  It offers everything the sigma does and is $1199 (same price but you do not get the Tamron TAP USB dock). I have not shot with the Tamron 24-70 yet, but based on my research the two are extremely similar - I think the Sigma offers slightly better bokeh and better quality control - you are more likely to get a sharp copy - this is something that Tamron has struggled with in the past on some of their lenses but the Tamron is lighter and some claim offers better VC. So while I can recommend the Sigma you should think long and hard - the Tamron may be just as good for you and a little lighter in your bag. Canon owners, if you don't care about image stabilization, the Canon 24-70 f/2.8 IS II is currently just $400 more, noticeably lighter and a bit sharper. The weight and sharpness of the Canon is hard to beat.Download RAWS to compare Sigma 24-70 OS HSM ART vs Canon 24-70 f/2.8 USM IIIf you would like to have in-depth discussions with me about which gear is right for you - consider joining the Photo Enthusiast Network - free 10 day trial at and not only can we have those discussions but you get access to HOURS of photography training videos, lightroom and photoshop tutorials and an awesome community of supportive individuals.