Autofocus / Manual Focus Performance and Metering
One of the reasons why it might be worth getting the RX100 IV over its predecessors is its superior autofocus performance. While all iterations of the RX100 use contrast detection autofocus, the RX100 IV has the faster and the more sophisticated implementation of contrast detection, which is particularly noticeable when photographing subjects in Continuous Servo / AF-C mode. Despite the constant “probing” of focus, the camera does a fine job of tracking subjects. Speaking of probing, I thought that I could get the camera to stop probing for focus with “Pre-AF” menu setting disabled. While that certainly stops the constant focus re-acquisition, it does not stop the occasional “probing” in AF-S mode! That is something that really annoyed me. I don’t know why Sony needs to do this, but the only way to get the camera to stop this behavior is to move the camera to “DMF” mode.
The 16 fps shooting speed of the camera is hard to fathom until you hear the camera fire away in the “Speed Priority Continuous” shooting mode. Indeed, the camera is insanely fast when compared to most other cameras out there. However, there are a few limitations. First of all, you cannot really get to 16 fps when shooting RAW – the camera slows down its shooting speed significantly. Second, the buffer is pretty limiting, only able to squeeze maybe 3 seconds of shooting total when shooting RAW (you can increase the shooting speed and the buffer by switching to JPEG though). Third, you need to be able to have fast enough shutter speed to be able to shoot fast bursts. Fourth, the fast fps shooting speed is only available in the specific “Speed Priority Continuous” mode, where the camera locks focus – you cannot get 16 fps in normal Continuous Shooting drive mode. And lastly, while the camera dumps images from the buffer into the memory card, some of the buttons like “Menu” and “Playback” become inoperable and the camera lags quite a bit.
Manual focus operation is intuitive and super simple. Once you switch the camera focus mode to Manual Focus (MF), all you have to do is rotate the focus ring on the lens. The moment you do that, the camera automatically zooms in to 8.6x zoom level and if you want to see what you are focusing on even closer, you can press the center button in the middle of the rotary dial on the back of the camera, which will zoom all the way to 17.1x zoom/pixel level. Personally, I practically never used manual focusing, because AF was good enough for what I used the camera for.
Overall, the camera focuses quickly and reliably in most conditions. In very low-light environments, AF speed and accuracy certainly do suffer, but that’s something we can expect from every camera…
Movie Recording
The Sony RX100 IV is a very capable camera when it comes to shooting video. It can create high-resolution 4K footage with stunning detail, something we often don’t even see on much more expensive, higher-end cameras. While the RX100 IV limits 4K video recording to 5 minutes, I found it to be plenty for recording typical footage with the camera. Obviously, with such high throughput rates, the bigger issue is not the time limit, but the recording media – you need fast SD cards with plenty of storage to be able to shoot 4K. I have recorded a couple of videos of my family in 4K and I was quite pleased with the results. But the biggest surprise is not 4K for me personally – it is the ability to shoot slow-motion video. That’s the real fun, because you can do all kinds of cool stuff with slow motion!
Take a look at the slow-motion videos that we recorded in a poorly lit indoor gym environment. In this first video, I am holding the paddles for a young Taekwondo fighter, who is performing continuous double kicks:
And in this one, yours truly is performing a quad kick on a target:
The camera only takes a few seconds to record actual footage, but as you can see, it can make pretty cool-looking videos that can be used for all kinds of fun!