Test

http://www.popphoto.com/gear/2013/03/lens-test-sigma-35mm-f14-dg-hsm-af

When the equivalent for M4/3?

No one knows.

Review - http://www.canonrumors.com/reviews/review-sigma-35mm-f1-4-dg-hsm/

Sony and Pentax of 35mm F1.4 DG HSM 'Art' lens will go on sale on 31st May :-)

Sounds good.

And more information on the 50mm Art. It's now seriously inviting comparison with the Zeiss 50mm.

http://www.imaging-resource.com/news/2014/01/08/sigma-50mm-f-1.4-art-targets-zeiss-otus-ignores-canon-l-nikon-glass

"But the most impressive information we gleaned? When discussing their goals of image quality and sharpness for the lens, Sigma mentioned they're confident they'll surpass competitive products from Canon and Nikon and are instead gunning for Zeiss's new 55mm Otus lens. It's a serious claim. The Zeiss 55mm f/1.4 Otus lens -- with its $4000 price tag -- is squarely aimed at high-end professional shooting such as fashion, advertising and editorial work. "

All posts for 50mm Sigma Art can go here --> http://www.personal-view.com/talks/discussion/9362/50mm-f1.4-sigma-art

http://www.thephoblographer.com/2014/06/17/one-sigma-35mm-f1-4-nikon-35mm-f1-8-g/

http://www.canonrumors.com/reviews/review-sigma-35mm-f1-4-dg-art/

Review

https://sonyalpha.blog/2018/07/10/sigma-35mm-f-1-4-dg-hsm-art/

Review

https://petapixel.com/2019/08/19/review-sigma-35mm-f-1-2-art-for-sony-fe-sigmas-fastest-lens-ever/

Review

https://admiringlight.com/blog/review-sigma-35mm-f-1-4-dg-hsm-art-sony-e-mount/