Sony RX10 Optics

Zoom
A very versatile 24-200mm equivalent zoom range, with excellent performance.

The Sony RX10 is equipped with a 8.8-73.3mm f/2.8 lens, offering a zoom ratio of about 8.3x for a very versatile 35mm-equivalent focal range of about 24-200mm.

Far-field performance appears to be excellent at f/5.6, with very good sharpness and contrast across most of the frame throughout the zoom range, and only minor softening and coma distortion in the extreme corners. Chromatic aberration is fairly low (the RX10 suppresses it), and flare appears to be well-controlled. This scene isn't great for judging distortion or performance in the corners, though, so see below for lab results on corner softness, geometric distortion, macro performance, etc.

Like other recent Sonys, the RX10 offers Clear Image Zoom up to 2x and standard digital zoom up to 4x. We're not big fans of digital zoom, but Sony's Clear Image Zoom does offer slightly better results than standard digital zoom, however it's difficult to see a difference with this subject. Edges appear a little better defined, but a scene with more detail is needed.

Macro
A larger than average sized minimum coverage area, with very good detail. The lens casts a large shadow at minimum distance and wide angle when using the built-in flash.

The Sony RX10 captured a slightly larger than average sized minimum area measuring 3.02 x 2.02 inches (76 x 51 millimeters) at wide angle. Detail is excellent across much of the frame, however corners show quite a bit of softness even at f/8 (most lenses show some softening in the corners at macro distances). The RX10's formidable lens casts a large, very dark shadow at wide angle when using the built-in flash, though, so you'll likely want to use external lighting for the closest RX10 macro shots. Or you could try using full telephoto which offers almost the same maximum reproduction ratio and casts no shadow.

Geometric Distortion
Very low distortion in camera JPEGs, much higher in uncorrected RAW files.

Geometric distortion in JPEGs is well-corrected, with only about 0.2% barrel distortion at wide angle, and under 0.1% barrel distortion at full telephoto.

Unsurprisingly, uncorrected RAW files show fairly high geometric distortion. We measured about 2% barrel distortion at maximum wide angle, and about 1.6% pincushion distortion at full telephoto. That's not unusual, though, and most RAW converters should automatically correct for it, but as mentioned, strong correction can lead to some additional softness in the corners.

Chromatic Aberration and Corner Sharpness
Moderately low chromatic aberration at wide angle; even lower levels at full telephoto. The lens produced some soft corners wide-open, though corner sharpness improved stopped-down.

Chromatic Aberration. Lateral chromatic aberration in camera JPEGs is well corrected, with moderately low amounts in the corners at wide angle, and fairly low amounts and telephoto, though you can see that some edge acuity it lost in the corners from suppression particularly at telephoto. The center shows very low levels at both wide angle and telephoto.

Corner Softness. Sharpness and corner performance is generally very good for the type and speed of lens, though our copy appears to have a slightly decentered element or group (unfortunate, but not at all unusual). In our sample, at maximum aperture (f/2.8), the bottom right corner is the softest at wide angle, but as you can see, sharpness is still pretty good, while the center is tack sharp. The blurring does however extend fairly far into the frame from the bottom right. At full telephoto, the upper left corner is the softest, while the center is sharp, though not quite as sharp as maximum wide angle. Note that some of the corner softness is due to strong distortion correction, both geometric and chromatic aberration (see below for uncorrected results).

Vignetting. You can also notice some minor corner shading ("vignetting") from the darker corner crops, though it's pretty mild.

F/4: Interestingly, stopping down to f/4 at wide angle actually produced slightly softer corners on the right-hand-side, though the left corners improved and the center remained tack sharp. Stopping down to f/4 improved sharpness in the corners at full telephoto slightly, while also improving contrast, though the center still isn't quite as sharp as wide angle. Corner shading also improved slightly, as did chromatic aberration.

Chromatic Aberration Suppression. As mentioned previously, lateral chromatic aberration in camera JPEGs is well corrected, with low to moderately low amounts at wide angle and telephoto. As you can see from the uncorrected RAW crops (lower set), lateral chromatic aberration is actually quite high and bright at maximum wide angle, and moderately high though not nearly as bright at full telephoto, so the Sony RX10's processor does a good job suppressing most of it in JPEGs.

Overall, very good to excellent performance for a 24-200mm equivalent f/2.8 constant aperture lens.

Coverage
Excellent accuracy from the electronic viewfinder and LCD monitor.

The Sony RX10's electronic viewfinder and LCD monitor both showed 100% coverage at wide angle and slightly over 100% at full telephoto, which is excellent, especially given the amount of geometric distortion correction being applied.