DxOMark Mobile Report: Samsung Galaxy S5

Summary

The Galaxy S5 is Samsung's latest flagship smartphone and successor to the Galaxy S4. It comes with a 16MP BSI CMOS sensor, an F2.2 maximum aperture, 4K video capture and phase detection AF, but has to make do without an optical image stabilization system.

Android 4.4 is powered by the latest generation Qualcomm quad-core 2.5 GHz Snapdragon S801 processor and 2GB of RAM. The Super AMOLED screen measures 5.1 inches and comes with the same 1080p resolution as the S4. You can choose between 16GB or 32GB versions and storage can be expanded via a microSD slot. 

With a DxOMark Mobile score of 79 the Samsung Galaxy S5 shares the number one spot in the DxOMark smartphone rankings with the Sony Xperia Z2, placing itself in front of the Nokia 808 and the Sony Xperia Z1. 

The DxOMark team reports that the Galaxy S5 images show 'good auto-exposure, pleasant, rich and realistic colors, good white balance, low noise levels in low light conditions and good sharpness and details in the center of the frame.' The testers found 'almost no color fringing or ringing' and liked the 'good image quality with flash.'

On the downside there is 'a noticeable loss of detail in low light conditions and non-uniform sharpness across the image field.' The team also found the AF not to be always accurate in Auto Mode.

In video mode the Galaxy S5 produces the 'best mobile video tested to date', with 'good autofocus and good textures.' On the downside there are 'visible color non-uniformities in some light conditions.'

Still Photography

Color, Exposure and Contrast

The DxOMark team found that the Samsung Galaxy S5 images show 'good auto-exposure even in difficult outdoor situations, pleasant, rich and realistic colors in all light conditions and overall good white balance.'

However, the testers also found that 'in high dynamic range scenes, images can be slightly burnt out' and 'with some indoor tungsten lighting a slight color shading can be noticed.'

Overall DxOMark awarded the Samsung Galaxy S5 scores of:

  • 4.5 out of 5 for Exposure
  • 4.5 out of 5 for White Balance accuracy
  • 4.0 out of 5 for Color shading in low light*
  • 4.0 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 the that when shooting with the Galaxy S5 'a lot of detail is visible across the frame' with 'low noise levels in low light conditions'. The testers found the S5's noise and detail levels to be 'better than the Galaxy S4'. On the downside there is a 'noticeable loss of details in low light conditions.'

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 that can be blurred away by noise reduction or obliterated by excessive sharpening (such as fine foliage, hair or fur).

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 a little lower under tungsten light than daylight but you the difference will be hardly noticeable in the image output. 
In terms of texture acutance under tungsten light, the Galaxy S5 lags slightly behind the best at low light levels but catches up in brighter 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 Samsung Galaxy S5 is only beaten by Sony's Xperia Z2.
The Samsung Galaxy S5's ability to retain sharp edges is excellent across all light levels. 
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.

Noise levels in daylight are low across all light levels.
Under tungsten light additional noise reduction kicks in in very low light and keeps noise levels down. 
Thanks to additional noise reduction in very low light the S5's noise levels measure lower than the competition at 20 lux. In brighter light the Samsung's performance is in line with its peers.  

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 Samsung Galaxy S5  were:

Natural scene

  • Texture (bright light): 4.8 out of 5
  • Texture (low light): 3.0 out of 5
  • Noise (bright light): 4.0 out of 5
  • Noise (low light) 3.2 out of 5
Bright light sample shot. 
100% crop: good detail across the frame, but slightly worse than the predecessor Galaxy S4. 
Low light (20 Lux) studio shot.
100% crop: low noise levels and no chroma noise, improved over the Galaxy S4
100% crop: still some detail visible at low light levels 

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 Samsung Galaxy S5 are shown below:

  • Almost no color fringing.
  • Almost no ringing noticeable.
  • Sharpness varies across the frame

Perceptual scores

  • Sharpness 3.5 out of 5
  • Color fringing 4.5 out of 5

Measured findings

  • Ringing center 9.0%
  • Ringing corner 3.7%
  • Max geometric distortion -0.3%
  • Luminance shading 22.4%

Distortion and Chromatic Aberrations

The graph shows the magnification from center to edge (with the center normalized to 1). The Sony Galaxy S5 shows slight pincushion distortion, which you are not going to notice in normal photography.
The Samsung Galaxy S5 shows very few lateral chromatic aberrations which won't be noticeable in the images. 

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 Samsung is doing very well in bright light but loses some of its edge in lower light conditions. The overall score is 80/100 in bright light and 59/100 in low light.

Pros: 

  • Autofocus is fast and accurate in trigger mode
  • Very little overshooting
  • Good scene change detection
  • Automatic face detection

Cons: 

  • Autofocus isn't accurate in auto mode
  • Autofocus slightly less repeatable in low light than in bright light
  • In low-light lab conditions the camera occasionally refocuses during capture, resulting in partially blurry pictures
Autofocus repeatability - average acutance difference with best focus: low light 11.92%, bright light 7.88%

Flash

DxOMark scored the Samsung Galaxy S5 82/100 overall for its flash performance which is three points less than the Sony Xperia Z2.

Pros: 

  • Good detail preservation, accurate white balance and color 

Cons:

  • Some white balance errors in mixed light 
  • No red eye correction

Overall DxOMark Mobile Score for Photo: 79 / 100

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. Bottom line: DxOMark found the Samsung Galaxy S5's overall video performance to be the best of all devices tested so far, with nice textures and good AF. Only in some light conditions the Samsung can struggle with color reproduction. 

Pros: 

  • Best mobile video tested to date
  • Well balanced video mode, without any major flaws
  • Good autofocus
  • Good texture

Cons: 

  • Visible color non-uniformities in some light conditions

Overall DxOMark Mobile Score for Video: 79 / 100