Sigma Mount Converter MC-11—Innovation Meets Optical Excellence

Sigma Mount Converter MC-11

The Sigma Mount Converter MC-11 is a must-have for Sony mirrorless camera users with Canon mount Sigma lenses, as K Madhavan Pillai finds out.

Sigma has produced several brilliant lenses over the past few years (the 50mm f/1.4 DG HSM Art being one of my favourites). And there’s no denying that the SonyA7R II is a camera with an extremely impressive high resolution sensor. So when we got the chance to put them together using the Sigma Mount Converter MC-11, it was an opportunity we were not going to miss!

Primarily meant for FE mount mirrorless full frame Sony A7 cameras, the converter is also compatible with Sony’s E mount NEX, A6000 and A5000 series of APS-C mirrorless bodies as well. At the moment, the MC-11 allows 19 of Sigma Sports, Contemporary and Art series of lenses (full frame and APS-C included) to be used.

The MC-11 has some smart features. Rather than simply relay information with cabling, a processsor within the MC-11 runs firmware to reinterpret data between the lens and the camera. This lets the MC-11 maximise compatibility for various camera AF and lens features, including stabilisation.

With the 50mm, the MC-11 allowed the complete range of Sony’s AF functions to be used, including phase detect AF (PDAF), Direct Manual Focus (DMF), S-AF, C-AF, Face Detect AF, and Eye Detect AF. Not all of these modes work with all Sigma lenses, as the lens compatibility chart indicates. For instance, the MC-11 does not enable DMF with the equally venerable 35mm f/1.4 DG HSM Art. Yet, as new lenses are released, the MC-11 can be updated through a micro USB port on the side, behind a rubber cover. An LED indicator on the MC-11 shows if a lens is compatible, incompatible, or if it needs updating.

In terms of construction, the converter is well-made, and seems sturdy enough to take on some of Sigma’s heavier lenses like the 150–600mm DG OS HSM Sports (which shows as being fully compatible with the all the AF modes of the A7R II, just like the Sigma 50mm Art). The converter itself is devoid of any lens elements or optics, and the inner surfaces are covered with felt flocking, to avoid internal reflections. Except for the rather heavy rubber cover over the micro USB port, I did not see any weathersealing gaskets on either side of the lens mounts.

In the hand, attached to the A7R II, the Sigma 50mm balanced pleasantly well. Also extremely pleasing to see were the results. It focused just about as quickly as Sony’s native lenses, though the 50mm also performs significantly faster with a DSLR like the Nikon D500 or the Canon 80D.

Yet, for a Sony user, the advantage of contrast detect combined with phase detect AF is in the precision of placing and achieving focus. In this, the Sigma 50mm Art shows its true potential, with its superb sharpness and its high levels of contrast maintained extremely well by the MC-11.

The Sigma Mount Converter MC-11 is currently the best among the various third party mount adapters available worldwide. Considering a price of Rs. 21,500, and the fact that no similar adapter is available in India yet, it is a perfectly sound investment for any Sony mirrorless camera user who has invested in Sigma lenses. And despite the warning on the side of the adapter that reads, ‘Designated Sigma lenses Only’, it worked quite satisfyingly with Canon lenses as well.