MrFotoFool said:
Very niche lens - I wonder who it is for. Wouldn't astro photographers want a wider angle? I had the Sigma 85 f1.4 EX for a few years and it was a nice lens, but too niche to carry most of the time so I finally traded it in. One thing about the 85, though, it was very handholdable. If this is heavier than a 70-200 2.8 I have a hard time understanding the appeal. It's not telephoto enough to be a wildlife lens. Maybe if you are a wedding and/or portrait shooter and you just want that little extra blur (to eliminate busy backgrounds on city streets, etc).
I have the Sigma 85mm f1.4 art (which is very different than the EX). I also have the Canon 200mm f2, which is my favorite lens (I've got a S____ ton of Canon glass). I'm not a pro, just a guy with a wife that understands.
The Canon 200mm is $6000, the Sigma 85mm is $1200.
I fricking love the Canon 200mm, it's by far my favorite lens and I've got the 600mm f4 II, I've got the 16-35mm III, I've got around $40K invested in Canon glass. The 200mm is the one lens that if I dropped it I would buy another one the next day, it's that good.
In my opinion, the Sigma is 80% as good as the Canon. Much better bang for the buck. Here are some shitty pictures I took when I was drunk at a party, that's all the Sigma. It's a great lens, it is becoming my second favorite lens:
http://www.mcvoy.com/lm/2018-otis-is-50/
Sigma has really stepped up their game. I'm not sure why you would want the 105 over the 85, well it will flatter your nose a bit more, but if it is like the 85mm art, you can't go wrong with that lens. These Sigma lenses are not like the shitty couldn't focus crappy quality Sigmas of 20 years ago, these are L quality glass and the auto focus works. Kudos to Sigma.