Sony RX100 IV

The RX100 has evolved over the years, and Sony’s fourth rendition is a far cry from the original model launched in 2012. The main update to note is a stacked Exmor CMOS sensor, integrating a layer of DRAM to handle large amounts of data.

Sony RX100 IV

Sony RX100 IV

This additional buffer grants access to a blistering maximum shutter speed of 1/32000sec, 16fps burst rate and can record HD movies in 40x slow motion. So it’s easy to see why Sony
has billed the new Mk IV as a ‘speed master’.

With some big features lying within a pocketable shell, we wanted to know whether it’s worth buying. At £759, the Mk IV is steeply-priced for a compact, and costs about the same as an enthusiast DSLR. But does the camera’s small size make it easier to shoot candids, and make it more likely to accompany you, wherever you go? We put it through its paces to find out.

Features & Build

At first glance you’d be hard pushed to tell the new model from its predecessor, because the exterior is almost identical. Its dimensions of 101.6x58.1x41mm means it’s just 3mm deeper than the Mk III. The major adjustments have taken place under the bonnet, with the new sensor headlining its raft of updates. The 1in chip may not be any larger, but it’s now augmented by an extended hi-speed processing layer and an additional DRAM memory buffer. The DRAM, paired with the Bionz X processor paves the way for the slow motion and fast burst rate, plus there’s 4K video recording.

On the top you’ll find the OLED Zeiss T* Electronic Viewfinder (EVF) which can be popped up by pressing a button. It’s the same size as the EVF found on the previous model, but its resolution has been doubled to 2359k-dot.

Impressively, Sony has managed to find space for a pop-up flash and Mode dial with MASP modes. The shutter button has a lever built around it to control the zoom and there’s a power button, too. Popping up the EVF turns the camera on, and pushing it back down turns the RX100 IV off by default; this feature can be disabled if you decide you want to continue shooting with the LCD screen.

Turn to the back of the Mark IV and you’ll find the 3in TFT LCD which can be tilted up 180° and 45° down to assist with awkward angles and shooting self-portraits. It also has a resolution of 1228.8k-dots. To the right of the LCD is a D-Pad with a scroll wheel for adjusting the exposure.

The Zeiss Vario-Sonnar T* lens is fixed, but it’s versatile with a film equivalent of 24-70mm and a wide maximum aperture of f/1.8 at 24mm, which narrows to f/2.8 at 70mm. There’s a Control Ring built around the lens which proves useful for changing exposure settings quickly too.

If you like the idea of composing on a smart device or immediately uploading your shots directly to social media, you can, because the Mk IV comes with Wi-Fi and NFC.


It’s best to hold the Mk IV with two hands as the grip is slight. The front of the Mk IV is sheer metal, though there’s a small thumb grip on the rear which houses a movie record button. The metal Control Ring around the 24-70mm lens is crosshatched and this gives added purchase when changing settings.

The 3in 1228.8k-dot display is sharp and clear, though we’d have liked to see touchscreen functionality on the bill. This would have made it easier to set a focus point – diving into a menu and using the D-Pad to set a point felt a little long-winded.

Sony has doubled the resolution of the pop-up EVF, taking the total to 2359k-dot. It’s super-sharp and a joy to compose with. You pop up the EVF and then pull a section out, and the EVF is then automatically turned on when brought up to your eye. Flipping the screen up while the EVF is set up will push it back in, but this is a minor issue. Overall, it’s a great addition, and its ability to be pushed down flush with the body gives a streamlined feel. The buttons dotted around the Mk IV are a little on the small side, so perhaps it’s best-suited to those with more dexterous fingers. But a function (Fn) button makes it quick to change key shooting parameters, and you can assign one of 51 functions to a Custom button too.

We found the AF to be a little pedestrian and it occasionally hunted for subjects low in contrast. When it came to write times, the Mk IV took 1sec to clear an Extra Fine JPEG and 1.4secs for a RAW. Switching over to continuous shooting, 45 JPEGs could be shot at 16fps before filling the buffer, and these took 13.7secs to write to card. Shooting multiple RAWs slowed the frame significantly, and 28 frames could be taken before it slowed further. These took 18secs to write.

Value for money

£759 buys you a lot of camera these days, so the Mk IV faces some stiff competition. Canon’s G5 X also has a 1in sensor, but sports a larger 24-100mm zoom and a touchscreen. The downsides are it can only muster 5.9fps and it’s less compact. Ricoh’s GR II offers a DSLR-sized APS-C sensor, but has a fixed 28mm f/2.8 lens and non-tilting LCD. Those after a prestige compact will need to weigh up the features of each, but if portability isn’t the most important factor, you could also get an enthusiast-level DSLR for the same outlay.


An EVF, 16fps shooting and 40x slow motion are desirable features, but we’d have liked a touchscreen to speed up focusing, so it’s four stars for Features & Build.

We were impressed by the Mk IV’s ability to record 4K video and shoot at 16fps, but write times were fairly average. The AF was also quite pedestrian so it’s four stars here, too.

Image quality is better than most smartphones, but is beaten by prestige compacts that feature a much larger APS-C sensor. Its ISO performance meant we could only award three stars for Image Quality – a larger sensor may have significantly boosted the score.

The RX100 IV delivers acceptable images for most uses, and its portability means you’re more likely to have it with you. But £759 is a lot to spend on a camera, so the unique features need to be high on your list.


  • Price: £759 (As of July 2016)
  • Resolution: 20.1Mp (5472x3648px)
  • Format: RAW & JPEG
  • Sensor: 1in Exmor RS CMOS
  • ISO: 125-12,800 (Expandable to 80)
  • Shutter: 30-1/32000sec & Bulb
  • AF system: Contrast detection
  • Focusing modes: Single-shot AF, Continuous AF, Direct Manual Focus (DMF), Manual Focus
  • Metering: Multi-segment, Centre-weighted, Spot
  • Burst rate: 16fps JPEG
  • Monitor: 3in, 1228.8k-dot tilting
  • TFT: LCD
  • Viewfinder: 2359.3k-dot 0.39-type Electronic XGA OLED Tru-finder
  • Pop-up flash: Yes
  • Hotshoe: No
  • Video: 4K 3840x2160 & Full HD
  • Connectivity: Wi-Fi & NFC
  • Write speeds: 1.4secs RAW, 1sec Extra Fine JPEG
  • Storage: SD, SDHC, SDXC, Memory Stick Pro Duo
  • Weight: 271g (body only)
  • Dimensions: (WxHxD) 101.6x58.1x41mm
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This review was first published in the March 2016 issue of Digital Photo - download back issues here.