Has full-time manual focus. Canon EF 24-105mm F/4L IS USM. Tamron SP 24-70mm F/2.8 Di VC USD. With full-time manual focus, you can move the focus ring whilst it is in AF (autofocus) mode. This means that you can make manual adjustments once the AF has finished, without changing to manual mode. From everything I've learned, it seems that the Sigma 24‑70mm f/2.8 DG OS HSM Art and the Tamron 24‑70mm f/2.8 Di VC USD G2 are pretty much on par with each other, but the Canon EF 24‑70mm f/2.8L II USM is one of the best zoom lenses in the world, and is superior to both of the others. I got an "ugly" Nikon 180/2.8 ED manual focus (it has a ding on the rear element!) for well under $150. Haven't actually tried it on the stars yet, but a viable option, so you can get the Canon zoom for your terrestrial endeavours and a used manual focus Nikon 180/2.8 ED for astrophotography.
The device is protected with extra seals to prevent failures caused by dust, raindrops, and water splashes. Has a metal mount. Canon EF 24-70mm F/2.8L II USM. Canon EF 85mm F/1.2L II USM. A metal mount is generally superior to a plastic mount as it is more durable. weight.
The Tamron SP 24-70mm F/2.8 Di VC USD is a fast standard zoom lens for Nikon and Canon full-frame DSLR shooters. Crucially offering built-in image stabilisation, something that the Big Two don't offer, the Tamron 24-70mm is also weather-sealed and cheaper. Read our Tamron SP 24-70mm F/2.8 Di VC USD review to find out if it's the best standard
Canon EF. Micro Four Thirds. weather-sealed (splashproof) Canon EF 24-70mm F/2.8L II USM. Olympus Zuiko ED 12-60mm F2.8-4.0 SWD. The device is protected with extra seals to prevent failures caused by dust, raindrops, and water splashes. Has a metal mount.
The f/2.8 lens is a better performer optically. The third lens is the Canon EF 24-105mm f/4L IS USM Lens that has been, at least prior to the 24-70 f/4L IS arrival, my most-used lens since it was introduced. It offers excellent image quality, a wide range of focal lengths and image stabilization. v8VY3.