Ursyn wrote in post #17138498
It's a perfect combination, however, the difference in prices is huge. Sigma 120-300 in B&H costs $3599 plus Sigma TC 2.0 $249 gives $3848. It's almost twice as much as announced Sigma 150-600 (~$2000).
We should wait for tests. In my opinion, crucial will be AF speed at long end.
That's my point. If you're after this kind of zoom and you have $2k to toss at it, you probably are someone who will end up going after something like the 120-300 F2.8 and a TC. If you're not, then the Tamron at $1k seems like the better buy. Again, the Sigma at $2k for literally the same thing, some minor performance differences for sure, hopefully it will be a very fast to autofocus lens, but $1k more for that? I would think someone willing to pay $1k just for faster autofocus, probably is also going to want to wait, and go for something that has F2.8 aperture, and not F6.3 at the widest.
Just a thought, as I'm someone with a 150-600 Tamron. Even if I didn't already have it, I would not consider this same lens at $2k, at all. But I definitely consider if I were to buy another fast big telephoto, it would be something with faster aperture, like the 120-300 F2.8 as it becomes a 600 F5.6 with the TC, and without it, a 300 F2.8, which is quite a big difference.