Even though the Sony A7R II and Sony A7S II are sharing a few similar features such as 4K internal recording, 5-axis image stabilization, enhanced high-speed auto-focusing along with similar price tags, overall these units are quite different beasts. Probably the major difference between the two cameras is the sensor technology and functionality on the video and stills side they provide respectively.
For instance, the A7R II sports a massive 42.4MP Full Frame back-illuminated CMOS sensor, whereas the new Sony A7S II comes with the improved version of the 12.2MP sensor that can be also found in its predecessor the original Sony A7s. Both cameras come with their strengths and weaknesses and definitely will serve better on certain occasions compared to one another. Here are some of the findings related to the A7R II and A7S II that Michael The Mentor shares with the community.
Despite the fact that many of the conclusions made in this video are related to the still-image performance of both cameras, there are many things that we can learn about their video functionality as well. For instance, the focusing system on the Sony A7R II is much better compared to the one in the A7S II. The latter struggles mainly when it comes to focusing on fast-moving subjects in stills mode as the accuracy is not as nearly as good nor as quick as the one on the A7R II.
Furthermore, it seems that the A7S II doesn’t have such overheating issues as the A7R II or at least not to that degree. Keep in mind, though, that if you have longer takes and shoot in hot environments this could become an issue for both cameras so considering an alternative option like an external recorder is highly recommended.
In terms of video functionality, the ISO performance of the Sony A7S II is a one to two stops better in comparison to the A7R II. It’s also interesting to note that in the ISO range up to 12,800 there aren’t any noticeable differences, but in the higher ISO modes the A7S II definitely has an edge.
Plus, the A7R II is limited to 25,600 as this is the maximum ISO you can get to in video mode. Unfortunately, both cameras have rolling shutter and moire issues to a certain degree, however, the wobbling and skewing artifacts are significantly reduced when you shoot using the120fps 1080p mode of the Sony A7SII.
Here is another video that summarizes the main differences between the two cameras:
Ultimately, it’s safe to say that the Sony A7S II is overall better optimised for video as the camera is packed with more pro video features such as S-Log 2 and S-Log 3 gamma curves, zebras, a gamma display, extremely useful slow motion modes such as 1080/120p that unfortunately can’t be found on the A7R II. As Michael points out, if you are a photographer that shoots video occasionally then the Sony A7R II would be the better all-in-one package for your needs. However, in terms of video functionality, the A7S II will serve those looking to use it predominantly for video better.