Sony a7S Full-Frame Mirrorless Camera, Part 2: Adapting Lenses to the E-Mount
Now that we have covered some of the important characteristics of lenses from a videographer's perspective, we'll discuss several of the lens-and-adapter combinations for E-Mount cameras, like the Sony a7S, that are also relevant for the Sony FS100 and FS700/R.
Nikon F Mount
Nikon lenses are the second most popular lens with photographers and lens rental houses but I have not tested any copies that are parfocal. Nikon lenses require a simple adapter to work with the Sony E-mount but no communication will happen between the camera and lens, including stabilization, EXIF data, auto focus, and iris control.
Nikon G series lenses have no iris ring on the lens body so you have to pair it with an adapter that also has an iris ring. Outside of the Nikon lineup (and this applies to Canon and a few other mounts too), some people really like Voigtlander for ultra-fast primes and Sigma for their ultra-fast zooms like the 18-35mm f/1.8 that is designed for APS-C sensors so it can be used on the Sony α7S in APS-C mode or works natively on the FS line of Super 35mm video cameras.
I’m not completely sold on the need for pairing an ultra-fast zoom lens on a full-frame sensor because you just don’t need the additional stop of low-light sensitivity with a clean and high ISO camera like the Sony α7S and some of what you gain in shallower depth of field you lose by switching to APS-C mode to accommodate a crop-sensor lens.
Sony α-Mount
Sony is now referring to all their α-mount (alpha) and E-mount (former NEX) as compatible, but you can’t mount an α-mount lens on an E-mount body without an adapter. Sony has two smart adapter models for APS-C and two for full frame E-mount cameras. The LA-E1 should be avoided, as iris changes via the camera body open the lens full wide open momentarily between each increment as you open the iris so you can’t use this adapter while filming if you want to use the footage. Both the LA-EA1 and LA-EA2 deliver a crop-sensor image, regardless of if you pair them with a full-frame lens.
The LA-EA2 adapter fixes the iris problem on the LA-EA1 and adds a translucent mirror in the sensor to enable PDAF autofocus and a convenient green focus check confirmation when the lens is wide open. The cost for this feature is a 1/3 stop of light loss and the widest iris opening is f/3.5 when PDAF is engaged.
The Sony LE-EA4 α-mount to e-mount adapter has a larger opening than the LA-EA2 adapter that was designed for APS-C or Super35mm sensors.
The LA-EA3 is a full-frame adapter and autofocus works in a CDAF mode on the α7S while the full-frame LA-EA4 is a full-frame adapter with a translucent mirror that offers PDAF autofocus. Neither offers stabilization and the LA-EA4 has the same 1/3 stop of light loss as does the LA-EA2.
Image stabilization is not available on the Sony LA-EA adapters because A-mount DSLR cameras have in-body stabilization and the LA-EA adapters don’t have in-adapter stabilization built-in. This wasn’t an issue with the FS100 and FS700 because their form factor and top lens placement is such that you can’t hand hold them as easily as you can a Canon C100, but the α7S wants to be hand held and could benefit from stabilization.
Because of the lack of image stabilization with a-mount lenses on the Sony α7S e-mount, I've decided that even though I have a full range of A-mount lenses for my FS100 and FS700, my Sony α7S needs its own lenses as it will be used for different types of work, largely handheld. Unfortunately I don’t think many former Canon users have come to this conclusion, and early adopters are struggling to get their Canon lenses to work as well on the Sony α7S as they do on their Canon DSLR bodies.
If you don’t mind forgoing the autofocus and camera EXIF data, you could also use a simple adapter, but be sure yours also has a manual iris ring on the adapter or you will be stuck full wide open. In theory, simple adapters should support full frame if the lens you mount on it is a full-frame lens.
On my FS100 and FS700, I personally use the Minolta 70-210 f/4 “beercan” lens and either the Konica-Minolta 28-75mm f/2.8 or Tamron 28-75mm f/2.8 lens for normal and long zoom. My favorite wide lens is the Sony 16-50 f/2.8 lens, although it is a crop-sensor lens so can’t be used on the α7S in full-frame mode without vignetting.
Related Articles
In this interview from the Sony booth at NAB 2023, Sony Senior Manager of Technology Mark Weir and Streaming Media's Shawn Lam take an up-close look at Sony's ZV-E1 full-frame, small form factor, mirrorless, vlog, E-mount camera with AI subject recognition.
In the last two articles in this 3-part series on the Sony a7S, we covered a lot of ground discussing what to look for in video lenses and lens adapters for the Sony e-mount that is native to the Sony a7S. Now it is time to take a deeper look at the Sony a7S as a video camera, with comparisons to the Canon 5D MKIII and Panasonic DMC-GH4.
People are buzzing about the Sony a7S, so Streaming Media Producer is launching a comprehensive three-part review. In this first part, we'll examine lens options for the Sony a7S and related cameras, as well as what to look for in a video lens.