The Sony RX100 range of compact cameras has won plaudits from critics and consumers alike over the past couple of years, finding favour as a model which you can slip into your pocket or handbag when you don't want to carry a DSLR or CSC around with you.
[Update: The RX100 IV (referred to as the DSCRX100M4 by some retailers) has since been replaced by the RX100 V and RX100 VI. Identical in many ways to the RX100 V, the newer camera offers an even more impressive performance, including a more advanced AF system and 24fps burst shooting. The RX100 IV is still a great camera though that delivers great images, smooth 4K video and top-notch performance.]
We're now onto the fourth generation of this popular camera, and there are whispers around the internet about the Mark IV being the compact to outshine every other compact ever made – it's a bold claim, although one that's backed up by some pretty impressive specs.
While Sony keeps the pixel count at 20.1 million, the same as the RX100 III, the sensor is Sony's new Exmor RS design, which employs a stacked structure with a DRAM (memory) chip attached. This enables readout speeds which Sony claims are 5x faster than conventional models, and facilitates performance improvements such as 16fps shooting without blackout, along with faster processing.
That sensor is joined by Sony's Bionz X processor, which is also designed for super-quick speeds, so all in all we should have a very nippy little camera on our hands – it's also claimed that autofocus speeds are improved.
The previous incarnation of the RX100 brought with it an electronic viewfinder, which came at the expense of the RX100 II’s hotshoe. The Mark IV retains the EVF, but there’s been a significant boost in resolution, to 2.35 million dots compared to the Mark III’s 1.44 million.
An electronic ‘anti-distortion’ shutter is included to reduce rolling shutter (jello) effect when shooting video. This also means you can shoot at super-fast speeds up to 1/32000 of a second, which is very useful if you want to shoot at wide apertures in bright sunlight, or if you’re trying to capture quick-moving action.
The RX100 IV’s lens remains a 24-70mm (equivalent) with an f/1.8-f/2.8 maximum aperture. That may seem quite a short focal length for a compact camera, but it’s a popular focal range for DSLR users, and it’s perfectly adequate for indoor and travel/street photography. A digital zoom is available if you need additional reach.
This is also the first RX100 model to include 4K video shooting, but it’s worth noting that this is restricted to five minutes, while Sony’s new RX10 II can shoot for up to 30 minutes. You can also record 40x super slow-motion video, which can be played back at a variety of frame rates.
This can be recorded in two- or four-second bursts, which doesn’t sound like a lot, but when these are played back in super slow-motion it translates into much longer clips – a two-second burst played at 1000fps becomes 80 seconds of video.
When it comes to regular shooting, many of the RX100 III’s very impressive features are retained, including five-axis image stabilisation to help keep images blur-free. There’s manual focus assist for those who like to focus their shots manually, along with focus peaking for extra help.
Wi-Fi and NFC are included, enabling you to remotely control the camera from your smartphone or tablet and quickly share your images. You can also download a selection of free and paid-for PlayMemories apps direct to the camera from Sony’s website, which provide you with extra functionality such as time-lapse or multiple exposure.
There is one area where the new camera has gone slightly backwards, and that’s battery life. The RX100 IV is quoted at a fairly lacklustre 280 shots compared with the Mark III’s (albeit not that much better) 320. Presumably this is a result of the more powerful sensor, but it’s something to think about if you’re going to be using this as your travel camera.
Sony hasn’t played around much with the design of the RX100 series in the past, and it’s the same story here – the only obvious difference between the Mark IV and the Mark III is the markings on the top plate.
The RX100 IV is a satisfyingly small camera considering the (relatively) large size of its sensor, and it’s small enough to fit comfortably inside a jacket or cargo pocket.
There are two ways of switching on the camera: you can use the on/off button on the top, or release the pop-up viewfinder via a switch on the side. As with the Mark III, activating the viewfinder is a two-step process – having popped it up you then need to pull it backwards from the housing. It would be nice if this was an automated process, which is something you might expect in a camera of this price.
The viewfinder switches on automatically when you lift the camera to your eye, and the screen is simultaneously switched off; it’s a fairly typical and intuitive system, although you can switch off the automation if you prefer.
The viewfinder is quite large and bright, but because there’s no eye-cup you may find that you can still see the scene around you when using it – sometimes this may be advantageous, other times it’ll be distracting. Pushing the viewfinder back into its housing switches the camera off, but again you can turn off this function if you want.
Flipping the RX100 IV’s screen up to face forwards puts the camera into self-timer (aka selfie) mode – you’ll need to move the viewfinder out of the way for a full view of the screen.
On the top of the RX100 IV is a mode dial with all the usual exposure modes, including aperture priority and full auto. Helpfully, there’s also a setting labelled MR (memory recall), under which you can save a set of custom shooting settings. You’ll also find a HFR, or high frame rate, mode, which gives you access to the slow-motion video options.
A switch around the shutter release button controls the zoom, while a ring around the lens can be customised to control different parameters. By default this controls particular settings in different modes – aperture in aperture priority mode for instance – but it may make more sense to you to set it to something else, such as exposure compensation; other options include ISO, white balance, Creative Style or zoom.
There’s also a small custom button which can be set to more than 40 different options, including ISO, metering mode and white balance.
Setting the autofocus point is pretty easy if you have the Flexible Spot area option selected: simply press the large central button on the back of the camera, then use the scrolling dial (which doubles as a navigation pad) to set the point you need. It would be simpler still if there was a touchscreen, though, and it remains disappointing that Sony chooses not to include these in its high-end compacts.
Pressing the Fn (function) button brings up a ‘quick’ menu, which can be fully customised to include the settings you want to adjust most often. I found it useful to include Quality as one of the options, as it enabled me to quickly switch to JPEG-only shooting, which is something which you frustratingly need to do in order to use certain settings such as Picture Effects.
This is something we’ve criticised in Sony cameras before, as it not only adds an extra level of faff when you’re trying to get a shot; it also means you don’t have a ‘clean’ version of the image to work with if you later decide you don’t like the filter effect.
Setting up the Wi-Fi functionality is quick, and once you’ve entered the password into your device it’s even quicker; and if you have an NFC-enabled device you simply have to tap it and the camera together to pair them. You can control the camera from your phone using the Smart Remote app, which enables you to adjust a useful range of settings including ISO, aperture, exposure compensation, focus point and zoom.
The Mark IV performs every bit as impressively as previous RX100 cameras. JPEGs direct from the camera are bright and vibrant, with true-to-life colours that have just the right amount of saturation for most subjects. You can choose from a range of Creative Styles if you want to experiment with different looks, such as Vivid, Landscape and Portrait, but the Standard setting produces perfectly good results in most situations.
Plenty of fine detail is visible in images shot at the lower sensitivity settings of ISO 100-400. Detail gradually starts to be lost as you move up the sensitivity range when examining images at 100%, although images viewed at typical print and web sizes retain and impressive level of detail right up to ISO 6400; quality isn’t quite as good at ISO 12800, but it’s still possible to make a decent-looking A3 print.
Comparing the equivalent raw image files, with no noise reduction applied, with the JPEGs you can see chroma noise, or coloured speckling, in images captured at higher sensitivities from around ISO 6400, although no banding is visible. You can apply custom noise reduction to reduce the speckling while retaining a little more detail than is apparent in the JPEGs, so long as you don’t mind retaining a little noise too.
Sample image: Direct from the camera, colours are nicely saturated without being overly vibrant; you can experiment with different Creative Styles if you want more (or less) saturation. Click here to see a larger image.
Sample image: The wide f/1.8 maximum aperture enables you to restrict depth of field very effectively – and it only rises to a still-impressive f/2.8 at the telephoto end. Click here to see a larger image.
There’s a small but marked improvement in signal to noise ratio performance, as indicated by our lab tests, when comparing the RX100 IV with the Mark III, especially when looking at raw images. The same can be said for dynamic range, more so at the lower end of the sensitivity scale, between ISO 100 and ISO 800.
Sony’s general-purpose multi-segment metering system works well most of the time in a range of shooting conditions, only requiring you to apply exposure compensation in the usual situations, such as when shooting very bright subjects or high-contrast scenes.
During my tests I tended to leave the Dynamic Range Optimiser on the Automatic setting. This feature helps to produce balanced exposures by analysing a scene and processing different areas of the image to retain more information in highlights and shadows; if you’re shooting a scene with areas of very high contrast it can be useful to push the DRO up to level 5, but you may find it can cause an image to look a little unrealistic, so it’s something of a trade-off.
Sample image: The RX100 IV’s low-light performance is impressive – its AF system was able to focus on this fine wire in very dark conditions, but I could barely see the wire while shooting. Click here to see a larger image.
Sample image: There are a few different Picture Effects on offer, such as this Miniature Effect. You can’t shoot raw when using these though, meaning you’re stuck with the effect whether you like it or not. Click here to see a larger image.
I found that the RX100’s auto white balance setting coped well with a range of different shooting conditions, including under artificial light, but you can choose from the usual range of presets if you find that auto isn’t giving you the results you want. The Shade setting can produce images that are a little warm, which may be to your liking, while other settings, such as Sunlight, tend to produce more accurate colours.
Autofocus speeds are pretty snappy, with the RX100 IV able to accurately and swiftly lock onto subjects in good light. As light levels drop the camera tends to take a little longer to focus, but it still manages to acquire positive focus even in very dark conditions. Handily, you can change the size of the focus point to small if you’re photographing subjects that aren’t well defined.
Sample image: The RX100 IV’s 24-70mm equivalent zoom range isn’t huge, but it gives you plenty of scope to shoot most everyday subjects. Click here to see a larger image.
Sample image: Having a tilting screen gives you scope to shoot from some awkward angles, such as very low down. Click here to see a larger image.
For a compact camera the 2.9x optical zoom length of the RX100’s lens may seem a rather paltry offering, but its 35mm equivalent of 24-70mm is the focal range that many DSLR users typically work with. As a bonus you get a wide maximum aperture at both ends of the optic – f/1.8 at the widest setting and f/2.8 at the telephoto end, both of which enable you to effectively blur the background to great effect, and use fast shutter speeds.
Sony is pushing the video capability of its new RX cameras, and not surprisingly given the addition of 4K video. The RX100 IV is limited to five minutes of 4K video recording at a time, but that shouldn’t present too much of a problem if you’re shooting lots of short clips to edit together. Although quality is good at both 4K and full HD, it’s possible to see a slight jello effect when panning the camera – it’s especially noticeable in 4K video shooting, so full HD is recommended if you’re a fan of panning shots.
We’ve put the Sony RX100 IV through our full set of lab tests to check its resolution, dynamic range and signal to noise ratio (noise). We’ve also picked out three of its key rivals, so that you can compare them for performance directly. The Panasonic LX100 has a larger Micro Four Thirds sensor, and is probably the top high-end compact camera with a zoom; the Canon G7 X, like the Sony RX100 IV, uses a 1-inch sensor; and the Fuji X30 is more of an old-school high-end compact with a smaller sensor than the rest, but a good lens and a good set of features for the money.
We’ve carried out lab tests on the Sony RX100 IV across its full ISO range for resolution, noise (including signal to noise ratio) and dynamic range. We test the JPEGs shot by the camera, but we also check the performance with raw files. Most enthusiasts and pros prefer to shoot raw, and the results can often be quite different.
Sony RX100 IV resolution charts
We test camera resolution using an industry-standard ISO test chart that allows precise visual comparisons. This gives us numerical values for resolution in line widths/picture height, and you can see how the Sony RX100 IV compares with its rivals in the charts below.
JPEG resolution analysis: The RX100 IV is just about the best in this group for resolution when you’re shooting JPEG images, although the Canon G7 X runs it a close second. Surprisingly, perhaps, the Panasonic LX100 is in third place – but then although its sensor is larger, its multi-aspect ratio sensor means it’s limited to a little over 12 megapixels. Less surprisingly, the X30 brings up the rear – it also has a 12-megapixel sensor, and a relatively small one at that.
Raw (converted to TIFF) resolution analysis: The pattern is repeated for raw files, with the Sony RX100 IV narrowly beating the Canon G7 X, and the Panasonic and Fuji in third and fourth places respectively.
Sample resolution charts
This is the chart we use for testing camera resolution. The key area is just to the right of centre, where a series of converging lines indicates the point at which the camera can no longer resolve them individually. We shoot this chart at all of the camera’s ISO settings, and here are two samples at ISO 200 and ISO 6400.
ISO 200: Click here for a full-size version.
ISO 6400: Click here for a full-size version.
Dynamic range is a measure of the range of tones the sensor can capture. Cameras with low dynamic range will often show ‘blown’ highlights or blocked-in shadows. This test is carried out in controlled conditions using DxO hardware and analysis tools.
Read: Noise and dynamic range results explained
Dynamic range is measured in exposure values (EV). The higher the number the wider the range of brightness levels the camera can capture. This falls off with increasing ISO settings because the camera is having to amplify a weaker signal. Raw files capture a higher dynamic range because the image data is unprocessed.
Sony RX100 IV dynamic range charts
JPEG dynamic range analysis: All four cameras turn in a very similar performance in this test, although this time it’s the Canon G7 X that comes out on top, narrowly ahead of the Sony RX100 IV.
Raw (converted to TIFF) dynamic range analysis: The raw files tell a different story, however. Here, the Panasonic LX100 displays a remarkably consistent dynamic range across the whole ISO range. The Sony and Canon continue their tit-for-tat battle, each showing a similar reduction in dynamic range at higher ISOs, while the X30 lags slightly behind, as you’d expect given its smaller sensor.
This is a test of the camera’s noise levels. The higher the signal to noise ratio, the greater the difference in strength between the real image data and random background noise, so the ‘cleaner’ the image will look. The higher the signal to noise ratio, the better.
Sony RX100 IV signal to noise ratio charts
JPEG signal to noise ratio analysis: The figures are so close here that you almost suspect camera makers are aiming for broadly the same levels of ‘acceptable’ noise in JPEG images.
Raw (converted to TIFF) signal to noise ratio analysis: Again, the Raw files tell a very different story. The Panasonic LX100 is the clear winner here, benefitting from its larger sensor and relatively low pixel count. The Canon G7 X is next, leaving the Sony RX100 IV trailing in third place, not far ahead of the Fuji X30. This means that the Sony’s raw files are inherently a little noisier than those of the Panasonic and Canon cameras.
Sample Sony RX100 IV ISO test results
The signal to noise ratio charts use laboratory test equipment, but we also shoot a real-world scene to get a visual indication of the camera’s noise levels across the ISO range. The right side of the scene is darkened deliberately because this makes noise more obvious.
ISO 200: Click here for a full-size version.
ISO 6400: Click here for a full-size version.
The RX100 IV delivers truly excellent image quality – arguably the best currently available from a camera of this size. What’s not small. however, is the price, and unless this falls dramatically it seems unlikely that many enthusiast photographers will be keen to splash out on the camera.
And while Sony has made some impressive improvements in the areas of picture quality and operating speeds, there are still enough niggles to make this a less-than-perfect compact, especially at its price point.
The collapsible EVF is very good, and increasing the resolution has made it even better to use than on the Mark III, but the two-step process of deploying it is still a little fiddly – it would be good if Sony could come up with a way of automating this.
The absence of a touchscreen continues to frustrate, especially when it comes to setting the autofocus point; while it’s not particularly difficult to do this it’s not very speedy either, and a second or two can make all the difference when you’re trying to capture a fleeting moment.
We’ve said it before – and we’ll no doubt say it again – but the fact that you have to disable raw format shooting before you can use certain settings, such as Picture Effects, adds another layer of inconvenience that we could do without.
The ideal would be having the option to shoot such effects in raw, so that you have the option to revert to a ‘clean’ image down the line, but if that’s really not possible then automatically switching off raw shooting would at least speed things up.
Although it’s great to have so many settings and options that can be customised, it can make the menus a little cumbersome to navigate; Sony could do with streamlining this process for the next iteration of the RX100.
We liked
For many users the most important factor when choosing a camera is image quality, and this is where the RX100 IV excels. It performs very well in low light, but it’s also fantastic in bright light thanks to the ability to shoot at fast shutter speeds. The focal length range is a little limited but it’s perfectly adequate, and the wide aperture at both ends enables great shallow depth of field shots.
We disliked
There’s no single, obvious thing to dislike about the RX100 IV – it’s more a case of several smaller issues which, added together, become rather frustrating. Not having a touchscreen isn’t the end of the world, but when you’re shooting a street scene, for instance, and want to quickly move the AF point from one side of the screen the other, having to do so manually can mean you miss the action altogether. It remains a little baffling why a camera of this price, and from an electronics giant, is missing such a feature.
Final Verdict
It may seem that I’ve picked up on quite a few negatives here, but the RX100 IV is an excellent compact camera – and, crucially, it produces excellent images. And it would be easier to let those smaller niggles slide with a product which didn’t come with such a high asking price, but they disappoint more here because of the cost. It’s also worth noting that this is the fourth generation of the RX100 series, so Sony has had plenty of opportunity to address these issues.
Overall, though, this is the best RX100 to date, and arguably the best compact camera currently on the market. If you want something that’s great for everyday shooting, includes some fun and high-end features such as 4K shooting, and fits neatly in your pocket – and if you can stretch to that asking price – then you can’t go far wrong.