Sony's popular Cyber-shot RX100 prosumer compact camera series has always impressed with its superb image quality in a pocket-size chassis.

But it is becoming like the Apple iPhone with its yearly upgrades.

The RX100 V retains its predecessor's 24-70mm, f/1.8- f/2.8 lens and 20.1-megapixel 1-inch stacked image sensor. The stacked layers in this image sensor allow more space behind each individual pixel for high-speed signal processing circuitry and faster data readout.

The Mark V now has an improved 24 frames per second (fps) shooting, compared with its predecessor's 16fps. Also, the Mark V now employs 315 phase-detection autofocusing (AF) points, in addition to 25 contrast-detection AF points. Sony claims that it now has a super-fast 0.05sec AF speed.

Looks-wise, there is not much difference from previous models. That's not a bad thing as the RX100 series has been very well designed.

Button layout is intuitive, with a mode dial on top for quick change of shooting modes. A rear clickable dial allows for swift access to flash, drive and other settings. A control ring around the lens barrel can be configured for lens zooming or other settings, via the camera's menu.

In manual mode, you can use the control ring to quickly adjust aperture size, and use the rear dial for changing shutter speed.

Street photographers who prefer to shoot with an electronic viewfinder (EVF) will like the Mark V's EVF. It is sharp and detailed. And when you pop it up, the camera automatically starts up so you won't miss the decisive moment.

You can also use the display to compose your shots. But it is not touchscreen. It can, however, be tilted down by 45 degrees and up by 180 degrees - perfect for selfie lovers. The camera automatically activates a 3-second timer when the display is in this "selfie position".

The camera starts up in 1.3sec and shuts down in 1.6sec - a wee bit faster than its predecessor.

Using an SD card with a writing speed of 95MB/s, the Mark V captured 73 RAW images in 3.6sec before the buffer ran out. That's hugely impressive for a compact camera.

Its AF is almost instantaneous under bright sunlight. In dim light, it takes about 1.1sec to achieve focus with AF-assist light.

You need to use the AF-A mode to fully utilise the 315 AF points.

Plus, during video recording in good lighting, it takes only 1sec to get a sharp focus when you pan to a new scene. That's 1sec faster than the competition.

Images are sharp with crisp details and great dynamic range across the entire focal range. Image-noise performance is similar to that of its predecessor, with no noise artefacts until ISO 800. Only at ISO 1,600 are the noise artefacts visible.

The 4K videos I shot look detailed and sharp. Indeed, this camera is good enough to give dedicated 4K camcorders a run for their money. But there is a 5min limit to its 4K video recording.

Battery life continues to be the RX100 series' Achilles' heel. And it seems to get worse with every new edition as the processing power gets better.

The Mark IV can shoot around 280 still images on a full charge, 30 fewer than the Mark III. The Mark V can manage only around 220 still images before the battery goes flat.

•Verdict: If you already have the RX100 IV, it does not make sense to upgrade. If not, the Sony Cyber-shot RX100 V is a superb compact camera to have. Just get an extra battery.