Video Mode

On the HTC One you don't have to enter a video mode to start recording. Simply press the video button in the camera app to start and stop. In the menu you can choose a video resolution and the video modes: Normal, Slow Motion, Fast HD (60 fps) and HDR video (1080p).

Simply press the video button to start and stop recording.
In the menu you can select the video modes and resolutions.

Filter effects are not available for shooting videos. If selected they are applied to the live view image but the preview switches to the standard non-filter view as soon as you press the video button. However, zooming is possible in video mode, you can take a still image while recording video and the focus can be locked to avoid focus "pumping." 

Video sample 1 - Good Light

In good light the HTC is capable of recording good quality full-HD video. Only when viewing the clips at full size some compression artifacts become available. The optical stabilization is very useful for keeping things steady when shooting hand-held and noticeably more efficient than most of the competition's digital stabilization systems. As you can hear in the sample clip below, like most smartphones the HTC is prone to wind-noise and unlike some compact cameras there is no wind-cut option.

Video sample 2 - Good Light

In less windy conditions the HTC is capable of recording excellent quality stereo sound as you can hear in the clip below. There is still no control over the recording volume but the HTC's sound quality is a notch above the competition. Thanks to the Beats Audio system and stereo speakers this is not only true for sound recording but also playback. 

Video Sample 3 - Low Light

Like in stills mode the HTC's fast F2.0 lens help keeping the sensor gain down when recording video. The end result is cleaner low-light video than most of the competition. In lower light the AF has a tendency to refocus without any obvious reason but as mentioned above, you've got the option to lock the focus in video mode.

HDR video

The HTC One is one of the first smartphones to offer HDR video in Full-HD 1080p resolution (the Sony Xperia Z is the other device we are currently aware of to offer this feature). The One does the same thing in video mode as it does in stills HDR mode and combines various exposures for each video frame into one. We have also noticed that the image is cropped compared to the standard video footage. This is to counteract any camera movement during HDR capture.

Below you can see a sample video of a high-contrast scene that was captured in the woods with the HTC One on a tripod. The trees in the shadow are very dark and at the same time highlights have clipped in the top left corner of the frame and, to a degree, also on the flowing water.

This is the same scene captured in HDR mode. As you can see the shadow areas have been lifted and the highlight clipping significantly reduced, with better detail on the flowing water. However, if you watch these videos at full-screen resolution the downsides to the HDR treatment become obvious. Despite the shadow areas being brighter they show visibly less detail than the standard version. Noise reduction is much heavier than in standard mode and blurs away most fine detail in the low-contrast foliage areas of the scene.

The frame is quite heavily cropped and then resampled to 1080p size which arguably contributes to the reduction in image detail. The illustration below shows the difference in framing. The large image shows the area captured in standard video mode. The green rectangular marks the framing of the HDR mode.

Slow motion video

Like some other recent smartphones the HTC One is capable of recording slow motion video. Footage is captured at approximately 4x speed which means 10 seconds of real-life action, when played back at the standard 30 frames per second, will turn into a 40 sec slow motion video. The video size is reduced to 768 x 432 pixels and no sound is recorded. When playing slow motion videos back in the phone's gallery app you can adjust the playback speed between original and 1/4 speed.