A 24-70mm f/2.8 is a bread and butter lens for a lot of photographers and videographers, covering a lot of the most commonly needed focal lengths and offering a wide maximum aperture to handle low-light situations. They can be rather expensive, however. Sigma's 24-70mm f/2.8 DG DN Art is significantly more affordable than most first-party options, and this excellent video review takes a look at the performance and image quality you can expect from it in practice.