DxOMark Mobile report: Sony Xperia Z3+

DxOMark Mobile Report: Sony Xperia Z3+

Summary

The Xperia Z3+ is the international version of the Japan-only Xperia Z4. In the camera department, at least on paper, it's only a minor upgrade over the predecessor Xperia Z3. In fact, the main camera specification remains unchanged. A 1/2.3-inch 20.7MP Sony Exmor sensor is coupled with a F2.0 lens offering an equivalent focal length of 25mm. The front camera, however, has been upgraded to a 5MP resolution and also offers a 25mm equivalent focal length.
However, despite the unchanged camera specs Sony has been able to improve camera performance. With a DxOMark Mobile score of 82 the Sony Xperia Z3+ scores three points higher than its Z3 predecessor and places itself at the number three position in the DxOMark smartphone rankings, behind the Samsung Galaxy S6 and Samsung Galaxy Note 4 and just ahead of the Apple iPhone 6 Plus. The DxOMark team reports that the Xperia Z3+'s images show 'good overall exposure, good white balance and pleasant colors in most situations'. They also found 'good detail preservation and thin noise when shooting outdoors and in low light conditions'. AF is fast and accurate in bright light and flash images show 'good detail preservation, low noise level and pleasant white balance'.
On the downside 'strong color shading is visible in outdoor conditions', there is a 'slight difference of sharpness between the center of the frame and the corners' and the testers also noted 'slight color fringing and ringing'. When the flash is mixed with tungsten light 'the white balance turns slightly red and slight color shading appears'.
When shooting in video mode 'stabilization is very good and captures pleasant video footage'. The team found 'good texture preservation and effective lens breathing correction' in video mode as well. However, 'some jittering artifacts are noticeable with indoor walking motion and the autofocus is slow'. There is also noticeable color shading under tungsten light.

Still Photography

Color, Exposure and Contrast

The DxOMark team found that on the Sony Xperia Z3+ images showed 'good overall exposure, good white balance in most situations and pleasant colors in all conditions.' On the downside 'strong color shading is visible in outdoor conditions'.

Overall DxOMark awarded the Sony Xperia Z3+ scores of:

• 4.6 out of 5 for Exposure
• 4.3 out of 5 for White Balance accuracy
• 4.0 out of 5 for Color shading in low light*
• 3.0 out of 5 for Color shading in bright light*
• 3.5 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 'in low light conditions, thin and pleasant noise can be noticed' and that the Sony Xperia Z3+ images show 'good detail preservation outdoors and in low light conditions'. There is no chroma noise either.

Texture Acutance

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.

	A dead leaf pattern is designed to measure texture acutance. It's obtained by drawing random shapes that occlude each other in the plane, like dead leaves falling from a tree. The statistics of this model follow the distribution statistics in natural images.
	In this example from a DSLR without edge enhancement, sharpness seems equal on edge and on texture. Many details are visible in the texture.
	In this second example, edges have been digitally enhanced, and the edge looks over sharp, with visible processing halos ('ringing'). On the texture part, many details have disappeared.

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.

Note: Acutance is a single value metric calculated from a MTF result. Acutance is used to assess the sharpness of an image as viewed by the human visual system, and is dependent on the viewing conditions (size of image, size of screen or print, viewing distance). Only the values of texture acutance are given here. The measurements are expressed as a percentage of the theoretical maximum for the chosen viewing condition. The higher the score, the more details can be seen in an image. 

 

For all DxOMark Mobile data presented on connect.dpreview.com we're only showing 8MP equivalent values, which gives us a level playing field for comparison between smartphone cameras with different megapixel values by normalizing all to 8MP (suitable for fairly large prints). DxOMark also offers this data for lower resolution use-cases (web and onscreen). For more information on DxOMark's testing methodology and acutance measurements please visit the website at www.dxomark.com.

In low light luminance texture acutance is sightly better in daylight than under tungsten light.

With its 20MP sensor the Xperia Z3+ beats the Galaxy S6 in terms of texture acutance in bright light but cannot quite keep up in lower light conditions.

Edge Acutance

Edge acutance is a measure of edge sharpness in images captured by the phone's camera. Again we're only looking at the most demanding of the three viewing conditions that DxOMark reports on - the 8MP equivalent.

In terms of edge acutance the Xperia Z3+ trails slightly behind the competition in lower light but can catch up in bright conditions.

Edge acutance decreases in lower light.

Visual Noise

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.

Thanks to noise reduction, noise levels remain stable across all light levels.

Noise levels are very similar under tungsten and daylight illumination.

Noise levels in bright and medium light are higher than the competition but noise reduction keeps things under control in low light.

Noise and Detail Perceptual scoring

DxOMark engineers don't just point camera phones at charts, they also take and analyze scores of real-world shots and score them accordingly. Their findings for the Sony Xperia Z3+ were:

Natural scene

• Texture (bright light): 4.8 out of 5
• Texture (low light): 3.6 out of 5
• Noise (bright light): 4.2 out of 5
• Noise (low light) 3.9 out of 5

Bright light sample shot	100% crop: good detail and low noise levels

Low light (20 Lux) studio shot	100% crop: noise has a finely grained and pleasant appearance

100% crop: still decent detail in low light

Artifacts

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:

• Slight difference of sharpness between the center and the corners of the frame
• Slight color fringing and ringing 

Perceptual Scores

• Sharpness 4.0 out of 5
• Color fringing 4.3 out of 5

Measured findings

• Ringing center 21.0%
• Ringing corner 11.4%
• Max geometric distortion -0.2%
• Luminance shading 13.2%

Distortion and Chromatic Aberrations

The graph shows the magnification from center to edge (with the center normalized to 1). Like many smartphones the Sony Xperia Z3+ shows a slight pincushion distortion, which you are not going to notice in normal photography.

Some lateral chromatic aberration is measurable but well within acceptable limits.

Autofocus

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+ does well in all light conditions. The overall score is 86/100 in bright light and 81/100 in low light.

Pros: 

• Fast and accurate autofocus in bright light conditions
• Very little overshooting

Cons: 

•  Slightly slow in low light conditions

Autofocus repeatability - average acutance difference with best focus: low light 1.12%, bright light 6.87%

Flash

DxOMark scored the Sony Xperia Z3+ 85/100 overall for its flash performance, which is one point higher than the iPhone 6 Plus. 

Pros: 

• Good detail preservation, low noise levels and pleasant white balance

Cons:

• When mixed with tungsten illuminant (20 lux), white balance turns slightly red and slight color shading appears.

Overall DxOMark Mobile Score for Photo: 84 / 100

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Video Capture

DxOMark engineers put phone cameras through a similarly grueling set of video tests, and you can read their full findings on the DxOMark website here. Overall DxOMark found the Sony Xperia Z3+ video stabilization to be very effective and footage to show good texture. However, some jittering is noticeable when walking while recording and tungsten light can cause a color cast.     

Pros: 

• Stabilization is very good and captures pleasant video footage
• Good texture preservation
• Effective lens breathing correction

Cons: 

• Some jittering artifacts are noticeable with walking motion indoors.
• Autofocus is slow
• Color shading is noticeable with tungsten illuminant.

Overall DxOMark Mobile Score for Video: 79 / 100

DXOMark Mobile Score

82

DXOMark Image Quality Assessment

With a DxOMark Mobile score of 82 the The Sony Xperia Z3+ improves three points over its predecessor Xperia Z3 and place itself at position number three in the DxOMark smartphone rankings.
In its testing the DxOMark team found the Xperia Z3+ to capture good detail and the exposure system to work reliably. In low light, detail is preserved well and noise is finely grained but the testers also found some corner softness and color casts in both day and tungsten light. The AF works reliably in all light conditions.
In video mode efficient digital image stabilization helps capture smooth video that shows nice textures but AF can be a little slow and 'jittering' can appear when walking while recording. For a more detailed analysis, visit www.dxomark.com.

Photo Mobile Score	84		Video Mobile Score	79
Exposure and Contrast	89		Exposure and Contrast	88
Color	80		Color	85
Autofocus	83		Autofocus	65
Texture	86		Texture	81
Noise	86		Noise	90
Photo Artifacts	77		Video Artifacts	78
Flash	85		Stab