Image Quality Tests


The RX100 includes a small built-in flash that will pop up whenever you engage the flash mode. You get the option of fill flash, slow sync or second-curtain sync (with an Auto option in the more camera-controlled exposure modes), and you can even assign flash exposure compensation as one of the options on the Fn button. This comes in useful, as the flash can be a bit over-enthusiastic, at its default setting.

The RX100's flash has a guide number of around 5.4m at ISO 100, this gives it working distance of between 3.39m at the wide-angle end of the lens, dropping to 1.25m at the long end of the zoom, at ISO 125. In Auto ISO mode, which by default will use up to ISO 3200, these extend to 17.1m and 6.3m respectively.

Compared to a small-sensor compact

The RX100 might look like a typical small-sensor compact camera, but in theory, its 1" sensor should be more capable when it comes to critical image quality. To show what sorts of benefits the RX100's larger sensor is supposed to offer, we've shot it alongside the Sony Cyber-Shot DSC HX20V - an 18MP compact superzoom based on a much smaller 1/2.3" back-lit CMOS sensor.

Sony DSC-RX100 Sony DSC-HX20V
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The RX100's processing isn't perfect - it looks a lot like some noise reduction is being applied and then the results sharpened, but the overall effect is a lot more pleasant, realistic and detailed. Even at low ISOs, (where both cameras have plenty of light) the larger sensor is simply capturing a cleaner image, meaning there's less need to over-process it.

ISO 3200

Sony DSC-RX100 Sony DSC-HX20V
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In the lower-light shot the RX100's large sensor advantage is shown very clearly - both through shallower depth-of-field and cleaner, less noisy rendering. Having Raw mode on the RX100 means that you can achieve slightly better image quality than is possible from JPEG, although the increase in potential resolution is relatively subtle, as we explain further down this page.

Automatic CA/Fringing Correction

Automatic fringing/CA correction in JPEGs is fast becoming a standard feature in compact cameras these days, and the RX100 is no exception. In JPEG mode almost all fringing is removed automatically. Process from Raw and, at the extreme edges, there are small hints of colored fringing but they're extremely well controlled, even at the wide-angle end of the lens.

Chromatic aberration doesn't appear to be a particular problem for the RX100. High-contrast edges at the extreme edges of the frame can show hints but it's never problematic.

As you can see, the JPEG engine is removing what little lateral CA there is (below left). Below right you can see what it would have looked like without that processing. Click here for the full-sized Raw conversion.

This 2 pixel fringing was some of the worst we could find in the many hundreds of images we shot with the RX100. Even if you choose not to apply Adobe Camera Raw's one-click defringing, a 2 pixel edge in a 20MP image is not likely to be a problem.
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Raw mode

The impressive thing about the RX100 is not so much that it can shoot Raw (all its peers can), but that it can do so really quite quickly. With a fast UHS-I card, the RX100 will happily keep shooting Raws if 'the moment' happens just after you grab your first shot.

The camera's JPEG engine does a good job with its sharpening. The results may not look especially pretty at 100%, but they convey the sensor's fine detail in print nicely. Running the Raw file through Adobe Camera Raw doesn't offer much scope for improved results - it's hard to apply finer sharpening without emphasizing noise. In this example, we've sharpened with Amount 60, Radius 0.7 and detail 5.
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The camera's JPEG engine generally does a pretty good job. We've not been huge fans of Sony's approach in the past as its rather heavy-handed sharpening can overwhelm very fine detail. However, with the 20MP the RX100 has to play with, any detail being lost is very, very fine detail in the real world - the textures you'd want to show, such as grass, are often captured over enough pixels that the processing does a good job of conveying them convincingly.

As such there's not a lot of scope for digging out more detail by converting from Raw. That said, the ability to fine-tune the sharpening to match the subject matter is always handy.

Noise reduction

In addition to being able to better tune sharpening to the specific image, shooting Raw provides a means of matching the level of noise reduction to the image you've taken. In general the RX100 does a fairly good job of using an appropriate amount of noise reduction at each ISO setting but obviously it can't tailor it to the subject. A default Adobe Camera Raw conversion will be effective at removing color (chroma) noise but leaves the luminance noise alone. This makes it easy to increase the amount of noise reduction you wish to apply, until you hit a balance of noise suppression and detail that you're happy with.

The RX100's JPEGs does a good job of balancing noise reduction with detail. This ISO 800 shot, taken in low natural light, manages not to get too smeary, while retaining some detail. Running the Raw file through Adobe Camera Raw allows you greater control over noise reduction. Here we've applied slightly less luminance noise reduction, to preserve a touch more detail.
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Color channel clipping

The Sony's fondness for bright JPEGs means very occasional over-exposure of the red channel. Here we can see a scene shot under bright, diffuse lighting where the camera has allowed red regions to clip into overexposure, despite the -0.3EV of exposure compensation applied. The result is reds with a rather magenta tone (Red having reached its maximum value, the ratio of red to blue gets recorded incorrectly).

Converting from Raw gives much more scope for correcting this overexposure (since the files still have all the available data - rather than having fixed the levels of each channel, relative to one another). With a little bit of tweaking, a more convincing pillar box red can be achieved, and the fine black lettering on the information panel has been recovered. Even better results would be possible with selective editing, but some highlight recovery and a slight shift of red tones away from magenta is enough to give a much more convincing image.

In this rather challenging example, the camera's red channel is starting to overexpose - giving a magenta tinge to the left flank of the postbox. Applying some highlight recovery to the Raw file and adjusting the hue response of red tones in the image allows the image to be rescued pretty effectively.
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To give you a chance to experiment with some of the RX100's Raw files, here are some examples to download, so that you can subject them to your own processing workflow.

Overall Image Quality/Specifics

In general, the RX100's image quality is very impressive. It captures lots of detail, presents it well and continues to do so pretty well even when the light starts to fail. There's not a lot more detail to be gleaned from shooting in Raw - the main benefits come from the more precise control you get over noise reduction and the ability to pull additional details out of the shadow regions (though DRO does that well too).

The RX100's exposure tends towards the brighter end of the scale, meaning there's a slight risk of losing highlight detail. It's worth keeping a close eye on the histogram or knocking the exposure compensation back by 0.3EV, if you're worried about such things (you can always push a slightly underexposed image if you want to, whereas you won't pull much back into an overexposed one). The Sony's white balance also appears to err on the side of cool. It may be fairly accurate, but we found a nudge or two of fine tuning towards the amber end of the scale gives more pleasant images in many cases.

The image processing is generally pretty good - there's a slight hint that the images are having a fair amount of noise reduction applied and are then being sharpened back up, but there's still an astonishing amount of fine detail to be found. The results are pleasantly un-compact-camera-like.

Overall, though, the RX100 turns in an impressive performance and, with 20MP, there's plenty of scope for cropping or downsampling - providing plenty of flexibility, no matter what you plan to do with the pictures.