In Canon land, it is obviously targeting the Canon EF 24-105mm f/4 USM L IS which has been the 1st choice among customers looking for a high quality, full format standard zoom lenses with a slightly longer reach. Interestingly the Sigma lens is just marginally more affordable than its Canon counterpart. Finding the ultimate general purpose lens for the new EOS 5Ds R cameras entering my kit was a high priority for me. With image quality results from the EOS 5Ds R now available in the Canon EF 24-105mm f/4L IS USM Lens Review, the three primary Canon lens choices are available for comparison. Top quality build and optics. Good (but not perfect) range on a crop camera. You will be missing ultra-wide (24mm is like 35 mm on a full frame camera) and f/4 is not ultra-fast. Personally I shoot with primes, nothing slower than f/2.8, but I often use them at f/4 or more stepped down. EOS C70 RF24–105MM F4 L IS USM LENS KIT. 24.6 x 13.8 (28.2 mm diagonal) Canon Control Ring Mount Adapter EF-EOS R Canon Drop-In Filter Mont Adapter EF-EOS R If you’re not too bothered about being able to shoot at f/2, the Canon 24-70 RF f/2.8 IS USM could be worth a look. It’s lighter and smaller than the 28-70mm, and you get an extra 4mm of focal Value For Money. Currently, this lens is available for around £405, which seems quite reasonable. Canon's 24-105mm f/4L IS USM is the closest equivalent, costing £640, which has a constant f/4 The Sigma 24-105mm F4 DG OS HSM lens is a great value for full-frame shooters who aren't in need of an f/2.8 zoom. See It Read Our Canon EF 24-70mm f/4L IS USM Review. 3.5 . Good . The Sigma has less vignetting. Looking at the specs and measurements, the Canon RF 50mm F1.2 L USM Lens vs. Sigma 50mm f/1.4 DG HSM Art Lens comparison shows these two lenses being rather similar. The Sigma is slightly lighter and smaller, but not weather sealed. The Canon has one additional aperture blade, 10 vs. 9. nmh9bvJ.