I took the ZEISS Batis 2.8/18, 2/25 and Loxia 2.8/21 for a spin on the Freefly MøVi M5 with the Sony a7SII, filming the same dancer in the same environment several times in order to compare the characteristics of the lenses and how they perform under bright light sources and during movement.
Balancing gimbals, and size of wide angle lenses
Since the MøVi came out a few years ago, I have used my M10 and M5’s on a lot of different productions. Like with all moving camera setups, wide angle lenses on gimbals emphasise movement more than long lenses do. Because of versatility and the ability to move more fluently, I have moved into using the small cameras like the Sony a7S and later the a7SII on the MøVi M5 rig, for example on this music video production on which I also already reviewed the 25mm version of the Batis lens series.
Balancing a gimbal is tricky business, and heavily depends on how evenly the weight is distributed. With many traditional wide angle lenses being quite heavy and with a large front diameter, you have to use risers like baseplates and also move the entire setup quite far back, which makes balancing much more difficult. There’s only so much you can move a camera back on a gimbal like the MøVi or Ronin before you hit the back motor.
Wide-angle Batis lenses
This is one of the reasons why gimbal operators like me have been impatiently waiting for lighter and more compact wide angles for a long time. The Batis 2/25 was a step in the right direction, and considering this is a full frame 35mm lens, it is quite wide indeed. However, sometimes it is still not wide enough.
Zeiss recently released the 18mm Batis version. At f/2.8, it is one stop slower than the 25mm version, but it’s a compromise I am willing to accept due to the fact that they were able to keep the measurements very very similar; only the front diameter was increased to 77mm, which is a very common diameter.
Autofocus on Batis
The Batis line is predominantly made for photographers because, as I mentioned in last year’s review, the lenses feature the focus-by-wire feature which makes repetitive manual focusing extremely hard. However, with autofocus in video becoming better and better, and particularly when working on a gimbal without a remote follow focus puller, that very autofocus feature is indeed worth taking a close look at. In this current test, the autofocus of both the 18mm and the 25mm Batis lenses performed remarkably well on the Sony a7SII. Unfortunately, we didn’t have a Sony a7RII in-house for this test, because this camera performs MUCH better using autofocus. The a7SII isn’t bad at it, just very slow, which means that fast movements don’t always give the right focus immediately. However, with infinity focus kicking in from 2 or 3 meters with most of these wide angle lenses, it’s not that noticeable. Watch out for my friend Philip Bloom’s upcoming autofocus test of various cameras – the Canon 1DX2 was the overall winner on that, but the Sony a7RII came in at a close second.
Zeiss’s Loxia line is E-Mount-native just like the Batis line, but it serves a different market. The Loxia lenses are extremely small and make the Sony a7 series camera look like a Leica Rangefinder camera when attached. They are fully manual with manual aperture and focus rings, and there are no autofocus functions whatsoever. They are all very similar in size, with minor differences in length. I am honestly quite amazed that they managed to get a 21mm lens into such a small form factor. At f/2.8 just like the Batis 18mm, this is a stop slower than the Batis 2/25. Again, a compromise worth taking.
Look comparison: Zeiss Batis and Loxia 18mm, 21mm and 25mm
I though it would be a good idea to compare these lenses, as they are very similar in focal length – 18mm, 21mm and 25mm are close enough to all be used on a gimbal for your everyday shoots, on a full-frame 35mm sensor like the a7SII’s imager. It’s very rare that we get to compare characteristics of lenses and in order to avoid a lot of distraction, I asked Brazilian dancer Rubens Oliveira to help us out. He was visiting Vienna as part of the Impulstanz dancing weeks (thanks to a sponsorship by Red Bull Amaphiko – here on Facebook), and we shot at GUXTU studio in Vienna thanks to Bernhard Klaffensteiner, with a very blank white background.
This is a very subjective (and non-scientific) lens test, but here are my impressions about the different looks between the Batis and Loxia line of lenses:
The Batis has a softer look with more graduated whites and a more graduated diffusion in both shadows and highlights. It appears less “sharp”, but probably due to it being just much less contrasty than the Loxia 2.8/21.
The higher contrast in the Loxia makes shadows appear deeper and whites brighter, which is quite interesting considering we shot in an S-Log 2 picture profile, which out of the camera appears quite “milky” anyway. If you look at the edges of the frame, the Loxia definitely has more vignetting and geometric distortion, which is certainly due to the smaller build – getting such a wide angle lens in such a tiny package certainly comes with some compromises. A very obvious difference is the lack of autofocus with the Loxia, which means that I had to set the focus to a fixed 2+ meter distance, which is already the infinity focus with the 21mm Loxia. You can see that Rubens is out of focus on some of the close ups in the Loxia portion of the video.
Overall, I am surprised how well all of the lenses performed in general, and especially how easy it was to rebalance the MøVi M5 after changing lenses. Bigger lenses can take a VERY long time to balance, but these are all so light and small that they make balancing a breeze, with the Batis line being exceptionally lightweight.
However, autofocus is almost a must when you are operating alone. This is why from now on, the Batis 2/25 will probably be my new favourite gimbal lens and will be with me on every shoot.