Sony Cyber-shot RX10 IV review

It's expensive, but it's virtually in a league of its own

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Best in Class

Build quality and handling

  • Dust- and moisture-resistant
  • Comfy handgrip
  • Weighs 1095g

Even for a bridge camera, the Sony RX10 IV is a chunky affair – weighing in at 1,095g it makes some DSLRs look lightweight. When you consider that Sony has managed to squeeze a 24-600mm optic into the body, however, it begins to look incredibly compact for what it offers. A Nikon 600mm f/4 telephoto prime lens, for instance, is almost four times the weight of the RX10 IV – and that's just the lens. Granted, that's not quite comparing like with like, but it does make you appreciate what a neat all-in-one solution this camera is, despite its bulk.

As you'd hope for with a camera demanding this amount of cash, the finish is very good. The RX10 IV is constructed from a blend of magnesium alloy and polycarbonate, and is dust- and moisture-resistant, while the generous handgrip enables you to keep a firm hold the camera even when the lens is extended. 

The control layout is pretty much the same as on the RX10 III, although the RX10 IV gains a new focus limiter button that's positioned on the left-hand side of the camera. This gives you the option to choose between the RX10 IV's entire focus range, or from 3m to infinity.

Back-button focusing can be incredibly useful, especially when you're tracking moving subjects, and while the RX10 IV doesn't have a dedicated button, as some premium DSLRs do, it's now possible to activate the camera's AF with any of the custom buttons – we reckon the AEL button positioned just below the rear command dial is the best choice for this.

The large lens barrel sports three lens rings controlling aperture, zoom and manual focus. If you wish, you can also zoom using the rocker switch encircling the shutter button, while the aperture ring can be either click-less, or set to click every third of a stop if you prefer. 

Overall, handling is very good. The controls are laid out in a logical manner, while the menu system has been refined. There are still reams of options, but the video settings are now in one sub-section, making it that bit easier to navigate. 

Autofocus

  • 315-point phase-detection AF
  • 0.03 sec focusing speed
  • Enhanced AF

The biggest update to the Sony RX10 IV over the RX10 III is the arrival of on-sensor phase-detection autofocus. And Sony hasn't scrimped on AF points either, with a total of 315 phase-detection points covering 65% of the frame. 

Because the RX10 IV takes advantage of the same BIONZ X image processor as Sony's flagship Alpha A9, it also enjoys the luxury of using the same autofocus algorithms used for focus tracking as in Sony's top-flight mirrorless camera. This is known as high-density AF tracking, and concentrates AF points around a subject to improve tracking and focus accuracy, with Sony claiming that even the most unpredictable subjects should be captured with ease.

Sony reckons focusing speeds should be as quick as 0.03 sec, and in use it's hard to dispute that – even at the 600mm end of the zoom range focusing speeds are very swift for static subjects. 

Flick the RX10 IV into AF-C (or AF-A, a new mode that Sony has added that will choose between AF-S and AF-C based on its assessment of subject movement), and it continues to impress. In fact, the tracking performance of the RX10 IV is nothing short of excellent – we haven't seen this level of performance on a bridge camera before, and it would embarrass some advanced DSLRs.

We shot with the AEL button programmed as our back-button focus control (and with the shutter button therefore only required to trigger the shutter), and with Lock-on AF: Flexible Spot M mode selected as our Focus Area. And, just as we experienced with the Alpha A9, a exorbitant array of AF points light up the viewfinder as it tracks your subject round the frame. What's really nice is that when you add in the Touch Pad AF control, which allows you to guide the AF area round the rear display with the camera raised to your eye, it's quick and easy tell the camera where you want to focus.

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Focusing is quick...
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..while the RX10 IV will happily track fast-moving subjects round the frame

For those shooting a lot of portraits, Sony's Eye AF technology does exactly as the name suggests. Activate this and the camera will lock on to you subject's eye, and hold focus and track the eye for as long as the mode is activated (it's initially set via centre button at the rear of the camera).