What would you choose among the 3 lens?

nightcat wrote in post #17044906
I'd take the Canon.

Agree. I have the old non Art Sigma and really enjoy it, but the AF is sometimes an issue. The Canon is a stop slower and the depth of field is not quite as shallow, BUT it has 4 stops of IS and the AF is very accurate. At it original introduction price of around $799 the Canon was overpriced, but the price was reduced to $599 and can be had for $549 right now at B&H with a current rebate.

Canon.

Been thinking of Sigma 30 1.4 A vs Canon EF 35 IS USM for over a half year. Still can't decide, lol. Right now I'm leaning towards the Sigma because of sharper in the middle up to f/2.8 (although the Canon is sharper in the corners) more useable focal lenght and f/1.4 of course.

If you can see it, you can photograph it with the Canon 35F2 IS. I may be exaggerating, but the IS is useful in low light, and the field of view on a crop better for people photos. I have the 35F2 and the newer 35F2 IS. The newer lens has fantastic AF, it is very sharp, and has great resistance to flare. The lens also gives you Canon color rendition, which I prefer to what I see from my Sigma 50 macro lens.
The Canon is sharp at F2. You can't go wrong with this lens, if the focal length works for your needs.

robienyshe wrote in post #17044838
If Performance is the priority which would be better to go for (Crop Sensor )

Define 'performance'. Is that the extra light gathering ability of the f/1.4 lenses? Image stabilization for shooting stationary subjects in dimmer light?

In terms of image sharpness, it's pretty close between the Sigma Art and the 35mm IS. Which lens it comes down to is going to depend on how you answer the question above.

adamo99 wrote in post #17048864
Define 'performance'. Is that the extra light gathering ability of the f/1.4 lenses? Image stabilization for shooting stationary subjects in dimmer light?

In terms of image sharpness, it's pretty close between the Sigma Art and the 35mm IS. Which lens it comes down to is going to depend on how you answer the question above.

I'm looking mainly shooting in low light indoor..I've the 50mm 1.8 and Focusing is very slow.. sometimes irritating.. I like the 85mm f1.8 but sometimes that's too long to use indoor..

Of those three, I'd take the Canon for the IS. I have the Sigma 35 Art... a very nice lens, to be sure... but wish it had stabilization.

I bought the EX version before the other two came out. It's good enough where I will not spend money upgrading to the other two at least not until I'm ready to go full frame and then I'll swap the 30/1.4 EX for the Canon 35/2 IS. If I was in the OP's shoes, and not itching to go full frame in the next year or more, I wouldn't hesitate buying a used EX 30 for a good price on the used market.