Movie Mode

The K-3 is the first top-end Pentax DSLR to feature a dedicated movie record button, and its video specifications see some of the biggest changes over its predecessor. Physically the camera gains a headphone socket for monitoring audio, to add to the microphone socket featured on the K-5s, but the more significant change is the move from the large and inefficient Motion JPEG compression system to the more refined H.264 format.

The camera records 1080 video at 24p, 25p or 30p, with the option for the latter two modes to be stored as 50i and 60i footage. The camera also offers an 'Interval Movie Record' option that shoots frames of up to 4K resolution at regular intervals and combines them as a movie. This mode has a shortest duration of 2 seconds between frames, though, so don't get your 4K shooting hopes up.

Sizes • Full HD
1920 x 1080 60i, ~22 Mbps
1920 x 1080 50i, ~22 Mbps
1920 x 1080 30p, ~22 Mbps
1920 x 1080 25p, ~22 Mbps
1920 x 1080 24p, ~22 Mbps
• HD
1280 x 720 60p, ~22 Mbps
1280 x 720 50p, ~22 Mbps
1280 x 720 30p, ~12 Mbps
1280 x 720 25p, ~12 Mbps
1280 x 720 24p, ~12 Mbps
Audio • PCM 16bit 48,000Hz
• Mono internal recording, stereo available via optional external mic.
Format • MPEG-4 AVC/H.264
• Motion JPEG (AVI) for Interval Movie Shooting (4K, 1080p or 720p)
Recordable time Approx 25 minutes (camera stops automatically to avoid over-heating)

The K-3 offers manual exposure during video capture, giving you full control over shutter speed, aperture and ISO, even while you're recording. There are also Program, Aperture Priority and TAv modes if you prefer, and the rear AF button can be used to perform single AF acquisitions as you shoot (though this will be quite noisy in your footage if you're using a lens driven by the camera's motor). Although all the live view AF modes (Face Detection, Tracking, Multiple AF Points, Select and Spot) are available when setting up your shot, they stop functioning when you start recording - the camera appears to just offer center-point AF if you hit the AF button.

And it's not just the more sophisticated AF modes that are only available in preparation for shooting. As with the K-5s (and several rival cameras), the K-3 offers focus peaking but only while setting-up a shot. The same is true for audio recording - the volume can be monitored via headphones and an on-screen display as you shoot, but can only be set prior to recording.

On one of Pentax's higher-end lenses that feature distance scales, it's possible to use focus peaking to plan your shot and work out the range across which you need to focus (as shown in sample 2). Without any guides as you're shooting, there's a risk of over- or under-shooting your target; something you're unlikely to notice until you try playing the footage back on a larger screen.

The camera does offer sensor shift-based shake reduction (Movie SR) during video capture. We've been pretty impressed with how steady the results are, and haven't seen any of the odd psychedelic warping that can occur when rolling shutter combines with digital correction.

The resolution of the K-3's footage isn't terribly impressive. In absolute terms, it appears to be a touch less detailed than the Nikon D610's output, but with less sharpening applied - meaning it appears noticeably less detailed. This leaves it a long way short of the standards set by the Panasonic GH3 and Sony RX10. So, while it's perfectly acceptable for a DSLR, there are much better choices if you're serious about video.

Sadly, as you can see in the third example, below, the camera seems to struggle to convey motion very well - presumably a result of its encoding.

Sample 1

This first sample was hand-held - propped against a railing, with the camera's Movie SR engaged to minimise camera shake. The camera's microphone is muted for this clip.

1920x1080 30p ~22Mbps, MOV, 31.5 sec, 83.6 MB  Click here to download original file

Sample 2

The second sample shows an attempt to manually pull focus between subjects, having used focus peaking to assess focus distances before shooting. The focus return to the person on the right of the image, at the end of the video appears to under-shoot the target - a risk when shooting without guides. The camera's microphone is muted for this clip.

1920x1080 30p ~22Mbps, MOV, 16.5 sec, 39.6 MB  Click here to download original file

Sample 3

This third sample shows an example of a pan, conducted in TAv mode, with the shutter speed set to 1/60th of a second and the aperture set to F8. The camera then adjusts ISO to maintain scene brightness. Focus is fixed at the beginning of the clip. Although there's only minimal sign of rolling shutter, the camera struggles to convey movement well, with considerable juddering in middle portion of the clip. Movie SR is off for this clip.

1920x1080 30p ~22Mbps, MOV, 20 sec, 53.6 MB  Click here to download original file

Sample 4

This clip was manually focused, with the aid of focus peaking, before recording started. Movie SR was On.

1920x1080 30p ~22Mbps, MOV, 20 sec, 53.6 MB  Click here to download original file