This lens is a foundational lens for a great deal of professional work. I had a very old (well, 10 years is a relatively long time) Sigma 24-70 f/2.8 lens, and recently replaced it with the Canon version. The Sigma was a good lens, but has no real weather sealing, the focusing is a bit slow (especially for sports and action), and it has been used quite a bit so it’s a bit worn. The glass is still basically good, but the mechanics of the Sigma lens just didn’t hold up over time. For me, the Sigma served it’s purpose and served me well. It’s just time to move on and retire the Sigma.
My plan is to use the new lens extensively to shoot basketball this fall and winter. I have previously used my prime lenses (I’ve used my 50mm f/1.2 quite a bit, and my 70-200mm f/2.8 as well). I plan to use this for football and soccer too – but not as much.
So, how does it work?
As you can see above, the images are pretty close to the same. The bokeh might be slightly different, but not enough for me to say one is better than the other.
So, why would I spend twice as much on the Canon lens? I think the differences are going to be more evident when the lenses are put to work.
First, the Canon lens is sealed against moisture and dust. The inner workings of the Canon lens are protected against moisture and dust that, gradually, or all at once, destroy the inside of the lens. Not all my lenses are weather sealed, but when they’re not, you have to be much more careful with your handling of the lens. I have, and will always, use a plastic bag over my lenses when I’m shooting in bad weather. Everyone usually does that – but the time it starts raining, or snowing, when you didn’t expect it, that’s the time some moisture gets into your lens and does damage. With a weather sealed lens, you don’t have to worry about the unexpected like you do with non-sealed lenses.
I purchased the Sigma lens when that was what I could afford. I used it for many years, until the day when I could afford the Canon lens. It is a very good lens, and served me well. So, I don’t think it was wrong for me to buy that lens.
Here’s another thing that is a factor when buying a Canon lens over another brand. Canon’s focusing mechanism is just the best and fastest out there (my opinion). I’ve used various lenses over the years for sports, and with action shooting, I get more sharp images with Canon than with other brands I’ve tried.
So, there’s my 2 cents worth. For some photo projects (landscapes, portraits, still life, etc.) the Sigma lenses are really good, and I like them – especially there newer art lenses. For sports and action though, I’d recommend sticking with Canon’s lenses for performance and build reasons. Otherwise, there are many good lenses out there that may fit the bill.