Performance

We found the Cyber-shot DSC-RX10 to be a capable performer, with good focus and shot-to-shot times, impressive continuous shooting speeds, and respectable battery life. The only real disappointment was how the camera 'locks up' for over ten seconds when shooting a long series of JPEGs (it's not quite as bad with Raw, as the bursts are shorter).

Operational Speed

Despite having a big lens to move, the RX10 is still able to start up in a respectable 1.8 seconds. If you quickly cycle the power on and off, it can take quite a few seconds longer, though that's probably not a common occurrence.

There's no noticeable 'lag' between the time you half-press and fully-press the shutter release, as one would expect from a camera in this class. The delay between shots is roughly half a second, regardless of the image quality setting.

AF System & Performance

The RX10 has what Sony calls 'Direct Drive SSM', which uses a 'supersonic wave motor' to reduce lens travel while the contrast detect system focuses. The result, according to the company, is high-speed focusing.

From our experience with the RX10, the camera is indeed very responsive when focusing in bright and 'medium' light. Performance isn't quite as snappy in low light, with focus times of around a second when the camera has to 'hunt'. We also noticed that the camera is more likely to pick a specific focus point (as opposed to just showing the 'green box' covering the scene) when the AF assist lamp is disabled.

Continuous Shooting

There are two different continuous shooting modes on the DSC-RX10: regular continuous and speed priority. Sony doesn't advertise the speed of the former, but it claims a 10 fps number in speed priority mode.

In regular mode, the camera adjusts the exposure and focus for every shot. In speed priority mode, focus is fixed on the first shot, while exposure continuous to be adjusted (though you can turn that off, if you prefer).

To put the DSC-RX10 to the test, we used a SanDisk Extreme Pro SDXC card, which advertises 90MB/sec write speeds.

Continuous mode

Sony doesn't advertise the frame rate of standard continuous mode, so we had to test it ourselves to find out. Here are the results:

Timing
Large/Xtra Fine JPEG
Raw
Raw+Fine JPEG
Frame rate 3.4 fps 2.7 fps 2.7 fps
Number of frames 38 shots 18 shots 14 shots
Buffer full rate 1.6 fps 1.8 fps 1.3 fps
Write complete 13 secs * 3 secs 5 sec
* After 38 shot burst

The RX10 took a respectable number of photos - even Raw - before slowing down. The camera isn't locked up for very long after you shoot, except if you take a big sequence of Extra Fine JPEGs.

Since focus is adjusted between every shot, you should be able to track moving subjects at this speed. In our experiences, the RX10 did that very well, whether it was tracking a person walking toward the camera or an approaching car. That fact that the image on the LCD/EVF is in real-time makes subject tracking that much easier.

Speed Priority mode

Sony does advertise the burst rate in Speed Priority mode, which is 10 fps. Let's see if the RX10 could match the company's claims.

Unlike with regular continuous mode, focus is locked on the first shot in Speed Priority mode. What you're seeing on the LCD or EVF isn't in real-time, either - it's post-shot review.

Timing
Large/Xtra Fine JPEG
Raw
Raw+Fine JPEG
Frame rate 10.0 fps 6.1 fps 6.4 fps
Number of frames 22 shots 10 shots 9 shots
Buffer full rate 1.4 fps 1.8 fps 1.2 fps
Write complete 11 secs * 2 secs 3 secs
* After 30 shot burst

As you can see, the 10 fps number is only for JPEGs; shoot Raw and the speed drops to around 6 fps. The RX10 still does a respectable job at this speed, especially when you consider that Raw files are about 21MB a pop.

Battery Life

The Cyber-shot DSC-RX10 uses the NP-FW50 lithium-ion battery, which is a fixture in Sony's larger cameras. This battery contains 7.7 Wh of energy, which translates to an impressive 420 shots per charge using the CIPA standard. As always, using Wi-Fi will decrease that number considerably.

The battery inside the RX10 is charged internally via a USB cable (attached to a wall socket or your computer). Some people view this as a blessing, others a curse. It takes a lengthy 310 minutes to charge the battery, and the internal charging method prevents you from easily having a spare battery on hand. Thus, it makes a lot of sense to pick up one of the BC-TRW or BC-VW1 external chargers, which are both considerably faster (especially the latter).