Video cameras on DSLRs - Pentax K-7

Pentax K-7

£850 (body)

Pentaxt K-7The Pentax K-7 launched last year with a feature set designed to appeal to semi-pro photographers, including HD movie mode. Uniquely, the K-7's highest resolution setting is 1536 x 1024p in a 3:2 image ratio (the same proportions as DSLR still images), which sits somewhere between the full 1920 x 1080p and smaller 1280 x 720p widescreen formats offered by everyone else. But you can also set 1280 x 720p widescreen if you want to.

Like Nikon, Pentax has gone for the Motion JPEG file format which produces relatively large files compared with AVCHD, and limits the maximum record times - it's 7 mins 23 secs on a 4GB card, a slight improvement on the Nikons. Pentax has resisted the temptation to reduce the audio sampling rate to save on file sizes, as Nikon has done. Consequently the sound quality is better, though file sizes are larger. There's also an external mic input for stereo recording if required. Pentax is also the only company here to include a built-in audio meter to monitor the sound.

The movie mode is set using the mode dial and recording started by pressing the shutter button. To control exposure you can either choose a fixed ISO and variable aperture, or set a fixed aperture and let the ISO adjust automatically. The former gives you more control over noise, but the sound of the aperture changing may be picked up by the mic, while the latter option gives you control over the depth of field. The video performance is somewhere in the middle of this group. The sharpness and detail are good, but the clips tended to underexposure as  the metering favoured the highlights but failed to retain as much shadow detail. The rolling shutter problem was also more visible when panning than on some of the other cameras here. 

Overall, as a first stab at video, Pentax has done a creditable, if not a barnstorming, job with the K-7.

Video Group Test: Video Modes - Pentax K-7

The K-7 tended to underexpose, making the video appear dark
for the most part and lacking in detail.

Specs

Pentax K-7

Price £850
Video Resolution 1536 x 1024
Compression Format M-JPEG
Maximum Clip Length 7 Minutes 23 Seconds
Screen Size 3"
Built-in Audio Mono, 44.1 KHz
Frame Rate 30fps
Memory Card SD/SDHC
Sockets Mic, USB, AV, HDMI
Video Focus Modes MF, AF
External Mic Yes
Dimensions 131 x 97 x 73mm
Weight 754g

Video Rating

Likes
Excellent sharpness, overall decent colour quality

Dislikes
Footage is far too dark in shadowed areas

Stars: 3.5 out of 5