I'm considering selling my Zeiss 35mm 1.4 in favor of the Sigma 35mm 1.4 ART if the AF works well with the C100 upgrade.

Does it work at all apertures? Or only at 1.4 like the 18-35mm? I heard the 50mm 1.4 ART works at any aperture other than 1.4 and I'm curious if the 35mm works the same way.

If it does work, does anyone have any experience with its performance?

Thanks!

Great lens, but it doesn't autofocus on the C100, at least mine doesn't.

If you want Dual Pixel AF support, I'm afraid you need to stick to Canon glass.

For the third party glass I've tested, you need to have the lens wide open for the continuous auto focus to work. This is true for me on the Tokina 11-16 II, the sigma 24-70, and the sigma 18-35 1.8.

I have seen people claim the new Sigma 50mm 1.4 Art lens works with the dual pixel auto focus at all apertures.

Ah damn. I was hoping it would work similar to the 50mm or the 18-35mm.

Thanks Bob, your comment about having to have the lens wide open pointed me in the right direction and in fact it turns out to be true for theSigma lens. Thanks.

Geoff

Sigma is working on this and I will post their development very soon.

Okay, here it is.

Sigma has informed me about the auto focus issue with the C100.

Sigma is working on the fix starting with the 35mm ART and 18-35mm ART Zoom lens. The firmware updates will be provided with the USB Dock.

Sigma has been looking into the usage of the lenses with the movies and this effort will be applied to the future firmware releases and the products.

Sigma is working on the fix starting with the 35mm ART and 18-35mm ART Zoom lens. The firmware updates will be provided with the USB Dock.

I will definitely start purchasing the Sigma primes (already have the 18-35) if they fix the Dual Pixel AF issue.