DxOMark Mobile Report: Samsung Galaxy S5
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."
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:
*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 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.
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.
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.
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
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:
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:
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 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.
DxOMark scored the Samsung Galaxy S5 82/100 overall for its flash performance which is three points less than the Sony Xperia Z2.
Overall DxOMark Mobile Score for Photo: 79 / 100
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.
Overall DxOMark Mobile Score for Video: 79 / 100