DxOMark Mobile Report: Sony Xperia Z3
The Xperia Z3 is Sony's latest flagship smartphone and replaces the Z2. It comes with a 5.2-inch 1080p screen and a Qualcomm Snapdragon S801 quad-core SoC clocked at 2.5 GHz that powers the Android 4.4 OS in a water- and dust-proof body. In terms of camera specs the new model offers the same 20.7 MP resolution on a 1/2.3 sensor as the predecessor but the sensitivity range has been expanded to ISO 12800 (in high ISO mode). Additionally, at 25mm equivalent, the new G-lens offers a wider angle of view. The Z3 shares the camera module with the smaller, but otherwise near-identical, Xperia Z3 Compact.
With a DxOMark Mobile score of 79 the Sony Xperia Z3 takes the number two spot in the DxOMark smartphone rankings, placing itself just behind the Samsung Galaxy S5 and in front of its own predecessor, the Xperia Z2.
The DxOMark team reports the Xperia Z3 images show "good detail preservation outdoors and in low light conditions, low noise levels in all lighting conditions, good overall exposure and pleasant colors in most situations." The autofocus is "very fast and accurate in bright light conditions."
On the downside, DxO says "color shading is visible in some outdoor pictures and low light conditions and strong flare is noticeable in sunny backlit outdoor scenes." When shooting with flash occasional overexposure and color shading in mixed tungsten light can be observed.
In video mode the Xperia Z3's "stabilization is very good and records pleasant video even with walking movement" and the Z3 video shows "low noise levels and good texture preservation". On the downside "autofocus is sometimes unstable, white balance transition is too slow and color shading is noticeable under tungsten light." Like in the still images "strong flare is noticeable in very bright conditions."
Color, Exposure and Contrast
The DxOMark team found that the Sony Xperia Z3 images show "good overall exposure" and that "colors are pleasant in most situations." However, the engineers also observed that "color shading is visible in some outdoor pictures and low light situations."
Overall DxOMark awarded the Sony Xperia Z3 scores of:
- 4.5 out of 5 for Exposure
- 4.1 out of 5 for White Balance accuracy
- 3.5 out of 5 for Color shading in low light*
- 3.5 out of 5 for Color shading in bright light*
- 3.0 out of 5 for Color Rendering in low light
- 4.5 out of 5 for Color Rendering in bright light
*Color Shading is the nasty habit cellphone cameras have of rendering different areas of the frame with different color shifts, resulting in pictures with, for example, pinkish centers and greenish corners.
Noise and Details
DxOMark's engineers reported that on the Sony Xperia Z3 "noise is very well controlled in all lighting conditions" and the images show "good detail preservation under daylight and and in low light conditions." There is also very little chroma noise in the Sony output. On the downside a "slight loss of detail compared to the Xperia Z2" can be observed.
Texture acutance is a way of measuring the ability of a camera to capture images that preserve fine details, particularly the kind of low contrast detail (such as fine foliage, hair or fur) that can be blurred away by noise reduction or obliterated by excessive sharpening.
Sharpness is an important part of the quality of an image, but while it's easy to look at an image and decide visually whether it's sharp or not, the objective measurement of sharpness is less straightforward.
An image can be defined as "sharp" if edges are sharp and if fine details are visible. In-camera processing means that it's possible to have one of these (sharp edges) but not the other (fine details). Conventional MTF measurements tell us how sharp an edge is, but have drawbacks when it comes to measuring fine detail preservation. Image processing algorithms can detect edges and enhance their sharpness, but they can also find homogeneous areas and smooth them out to reduce noise.
Texture acutance, on the other hand, can qualify sharpness in terms of preservation of fine details, without being fooled by edge enhancement algorithms.
At first sight, the images from these two cameras may appear equally sharp. A sharpness measurement on edges will indeed confirm this impression, and will even show that the second camera is sharper. But a closer examination of low contrasted textures shows that the first camera has better preservation of fine details than the second. The purpose of the texture acutance measurement is to qualify this difference.
Visual noise is a value designed to assess the noise in an image as perceived by the human visual system, depending on the viewing condition (size of image, size of screen or print, viewing distance). The measurements have no units and can be simply viewed as the weighted average of noise standard deviation for each channel in the CIE L*a*b* color space. The lower the measurement, the less noise in the image.
Noise and Detail Perceptual scoring
- Texture (bright light): 4.8 out of 5
- Texture (low light): 3.5 out of 5
- Noise (bright light): 4.2 out of 5
- Noise (low light) 3.7 out of 5
Phone cameras, like entry-level compact cameras, tend to suffer from artifacts such as sharpening halos, color fringing, vignetting (shading) and distortion, which can have an impact on the visual appeal of the end result. DxOMark engineers measure and analyze a range of artifacts. Their findings after testing the Sony Xperia Z3 are shown below:
- strong flare in backlit sunny scenes
- stronger ringing than most other high-end smartphones.
- Sharpness 4.0 out of 5
- Color fringing 4.2 out of 5
- Ringing center 21.9%
- Ringing corner 15.1%
- Max geometric distortion -0.1%
- Luminance shading 23.1%
Distortion and Chromatic Aberrations
DxOMark also tests autofocus accuracy and reliability by measuring how much the acutance - or sharpness - varies with each shot over a series of 30 exposures (defocusing then using the autofocus for each one). As with other tests these results are dependent on the viewing conditions (a little bit out of focus matters a lot less with a small web image than a full 8MP shot viewed at 100%). Using the 8MP equivalent setting, the Sony Xperia Z3 is among the best devices tested so far and has slightly improved over its predecessor, the Xperia Z2. The overall score is 92/100 in bright light and 80/100 in low light.
- very fast and accurate autofocus in bright light
- very little overshooting.
DxOMark scored the Sony Xperia Z3 83/100 overall for its flash performance which is two points lower than the Xperia Z2.
- Good exposure, white balance and detail preservation
- Color shading is noticeable under tungsten lighting (20 lux)
- Slight over-exposure without additional light sources and slight under-exposure when mixed with tungsten light
Overall DxOMark Mobile Score for Photo: 81 / 100
DxOMark engineers put phone cameras through a similarly gruelling set of video tests, and you can read their full findings on the DxOMark website here. Overall DxOMark found the Sony Xperia Z3's video performance to be good, with very good digital stabilization, good texture and low noise levels. However, like on the Z2 the AF can be a little unstable and white balance is unreliable under tungsten light.
- Stabilization is very good and helps capture smooth video even with walking motion
- Low noise level and good texture preservation
- Autofocus lens breathing correction improves user experience
- Autofocus sometimes unstable
- White balance transition too slow
- Color shading noticeable under tungsten light
- Strong flare noticeable in very bright conditions
Overall DxOMark Mobile Score for Video: 76 / 100
DXOMark Image Quality Assessment
The Sony Xperia Z3 cannot significantly improve over its predecessor, the Z2, but with a DxOMark Mobile score of 79 it's enough to share the spoils with its predecessor and the Samsung Galaxy S5 at the top of the DxOMark mobile ratings table.
In testing the Xperia Z3 images show "good detail preservation outdoors and in low light conditions, low noise levels in all lighting conditions, good overall exposure and pleasant colors in most situations." The autofocus is reliable as well but "color shading is visible in some outdoor situations and flare can be observed in backlit scenes. Flash exposure is a little shaky and white balance a little unreliable when flash is mixed with other light sources.
In video mode the Xperia Z3's "stabilization is very good" and videos shows "low noise levels and good texture preservation". On the downside the AF can be a little unstable and color casts can be seen under tungsten light. For a more detailed analysis, visit www.dxomark.com.
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from After the Rain