DxOMark Mobile Report: HTC 10

Summary

Announced earlier this week, the HTC 10 is the Taiwanese manufacturer's latest flagship model and comes with a top-end camera specification. A 1/2.3-inch 12MP sensor is combined with a fast F1.8 aperture and optical image stabilization. The AF is laser-assisted and the HTC 10 is also the first smartphone to come with optical image stabilization in the front camera. 

In the DxOMark test the HTC 10 performs very well and with a DxOMark Mobile score of 88 takes the joint number one spot, next to the Samsung Galaxy S7 edge. In still image mode the testers liked the "very good detail preservation, fast and accurate autofocus, good exposure and good noise reduction in low light conditions". They also found the white balance and color rendering to be generally good. On the downside, there is a "visible loss of sharpness in the corners, some luminance noise in the sky and visible vignetting and noise in the corners when shooting with flash". In some pictures the testers also found slight highlight clipping.

When shooting video the test engineers were impressed by the "good stabilization, good exposure, good white balance and color rendering and accurate and fast autofocus". However, they also noted "some residual motion in walking movements, luminance noise in low light conditions and occasional focus failures while panning". 

Still Photography

Color, Exposure and Contrast

The DxOMark team found the HTC 10 images to show "good exposure, good white balance in indoor conditions and neutral white balance and accurate color rendering in outdoor conditions". However, they also criticized "slightly blown highlights in some outdoor images and occasional white balance irregularities."

Overall DxOMark awarded the HTC 10 scores of:

  • 4.6 out of 5 for Exposure
  • 4.5 out of 5 for White Balance accuracy
  • 4.3 out of 5 for Color shading in low light*
  • 4.5 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 the HTC 10 images show "very good detail preservation in all conditions and good noise reduction in low light". On the downside "some luminance noise is visible in the sky".

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.
Texture acutance is pretty much identical in daylight and under tungsten light. 
The HTC 10, Nexus 6P and Galaxy S7 edge are on very similar levels in terms of texture acutance.

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 good light the HTC's edge acutance is a touch lower than some competitors.
Edge acutance is consistent across 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 are low at all light levels.
In terms of noise the HTC 10 compares well to its competitors, only the Galaxy S7 produces less noise at all light conditions.

Noise and Detail Perceptual scoring

DxOMark engineers don't just point camera phones at charts, they also take and analyze plenty of real-world shots and score them accordingly. Their findings for the HTC 10 are:

Natural scene

  • Texture (bright light): 4.8 out of 5
  • Texture (low light): 4.0 out of 5
  • Noise (bright light): 4.2 out of 5
  • Noise (low light) 4.0 out of 5
Bright light sample shot
100% crop: very good detail preservation
100% crop: some luminance noise is visible
Low light (20 Lux) studio shot
100% crop: good noise reduction
100% crop: very good detail preservation

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 HTC 10 are shown below:

  • Some corner softness
  • Some Moiré on high frequency patterns
  • Slight ringing
100% crop: Moiré patterns can occasionally be visible

Perceptual Scores

  • Sharpness 3.8 out of 5
  • Color fringing 4.1 out of 5

Measured findings

  • Ringing center 7.1%
  • Ringing corner 3.1%
  • Max geometric distortion -0.4%
  • Luminance shading 9.3%

Distortion and Chromatic Aberrations

The graph shows the magnification from center to edge (with the center normalized to 1). HTC 10 shows a very slight pincushion distortion, which you are not going to notice in normal photography.
Chromatic aberrations are very well under control. 

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 HTC 10 performs very well in all light conditions. The overall score is 92/100 in bright light and 93/100 in low light.

Pros: 

  • Fast and accurate autofocus in all light conditions
Cons: 
  • Some slight irregularities in bright light trigger mode
  • Occasional failure in outdoor scenes
Autofocus repeatability - average acutance difference with best focus: low light 1.66%, bright light 2.70%

Flash

The HTC 10 edge offers a dual-LED flash for illumination in very low light. DxOMark scored the camera a good 83/100 overall for its flash performance. 

Pros: 

  • Good exposure, color and detail preservation in flash mode

Cons:

  • Some shading and noise visible in the corners
  • Slightly under-saturated images when flash and tungsten light are mixed

Overall DxOMark Mobile Score for Photo: 88 / 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. Overall, DxOMark found the HTC 10's video mode to perform very well, with fast autofocus, efficient stabilization and good color. On the downside, some noise is visible, especially in low light.     

Pros: 

  • Good white balance and color rendering in all conditions
  • Accurate and fast autofocus
  • Good stabilization

Cons: 

  • Some residual motion in walking movements
  • Noise on some color patches, particularly green, blue and cyan
  • Luminance noise visible in low light conditions
  • Occasional focus failure while panning (lens remains unfocused)

Overall DxOMark Mobile Score for Video: 86 / 100

DXOMark Mobile Score
88

DXOMark Image Quality Assessment

With a DxOMark Mobile score of 88 the HTC 10 edge takes the joint number one spot in the DxOMark smartphone rankings, next to the Samsung Galaxy S7 edge. The testers liked the good levels of detail captured by the device, the fast and accurate AF and the well-balanced noise reduction. Main points of criticism were corner softness of the lens, luminance noise in areas of plain color and corner shading in flash use. 

In video mode the HTC 10 produces good exposure, white balance and color. The AF works reliably and quickly but again some noise is visible. For a more detailed analysis, visit www.dxomark.com.

Photo Mobile Score 88   Video Mobile Score 86
Exposure and Contrast 89   Exposure and Contrast 88
Color 84   Color 86
Autofocus 93   Autofocus 82
Texture 93   Texture 85
Noise 87   Noise 87
Photo Artifacts 89   Video Artifacts 90
Flash 83   Stabilization 83