Blackmagic Forum

Hi, I recently bought the BMPCC 6K and I am using the 18-35 Sigma Art lens. Autofocus does not seem to work with this lens on this camera. I downloaded the Sigma Optimization software and installed the latest update but I doesn't fixed the problem. I would really appreciate if anyone has a suggestion.

Yes, Autofocus on some third party EF lenses is either not currently supported, or AF is very slow.
This Sigma lens has a problematic history, with BMD and other cameras, from what I have read.

What?

I have the same setup and it works perfectly!
I use the 50mm ART too.

Normally, I seem the one facing irresoluble problems.

But, my Sigma 18-35 Art (Still) works fine with the BMPCC 6K, exposure and AF.

Same here, it works.

Karnaim wrote:Hi, I recently bought the BMPCC 6K and I am using the 18-35 Sigma Art lens. Autofocus does not seem to work with this lens on this camera. I downloaded the Sigma Optimization software and installed the latest update but I doesn't fixed the problem. I would really appreciate if anyone has a suggestion.

What are your expectations for autofocus? This may determine if there is actually an issue with the lens. If you are looking for continuous AF, then it won’t work—not with any lens. If the push to AF function doesn’t work on that lens, try another lens to see if it is isolated to the camera or to the lens.

thanks for your comments.
I am aware that this camera has no continuous AF. What happens is that I try to focus on something by pressing the focus button and stay for several seconds trying to focus. I tryed with a Canon 50mm 1.4 lens and it worked perfectly

You mean that it is pretty slow and "struggles" a bit? If so then I'm experiencing the same. Technically it works, but most of the time it's very slow (definitely slower than other lenses I tried) and seems to struggle more than others to find the focus. But it's definitely doing something (not like nothing happens when you press AF)

Not sure if that is something related to updating the firmware of the lens maybe or adjust via the Sigma dock?

Or, maybe, gently cleaning the contacts on the lens mount.

I mean that it is very slow and "struggles" a LOT ! in situations where the object should be easy to focus...
most of the time it doesn't find focus and stays forever trying.

thanks,. I'll try both options ! let you know

Download the new FW 6.6, and give the lens AF another try. AF performance has been improved in this new update.