Pentax K-30 Video Recording

High-definition video capture is now ubiquitous in current single-lens reflex cameras: all of the major manufacturers now provide some form of video capture. The Pentax K-30 offers a reasonably rich feature set, although it does lack a couple of consumer-friendly features found on some models. Videos can be recorded at up to Full HD resolution using H.264 compression, but there's no support for full-time autofocusing during movie capture, nor does the K-30 have a wind cut function, both options that consumer videographers might typically expect to see. Pros, meanwhile, will find offputting the absence of external microphone connectivity. The K-30 does however support manual exposure control, manual audio levels control, and adjustable frame rates, all functions that professional use typically demands. For those who like to cater to their creative side, the K-30 does offer a generous selection of pre-capture video filters.

Overall, we found the Pentax K-30's video feature set to be a worthwhile step forward from past Pentax SLRs, although the lack of a dedicated Video button is a shame, as is the choice of a monaural mic. Consumers may mourn the lack of full-time autofocus, but given its relatively slow and hesitant operation, it probably wouldn't have been terribly useful regardless. If you're willing to live without it and either focus manually or plan your shots around your depth of field, you should be able to achieve good results with the K-30. Overall, we felt the K-30 provided very decent video, with good color and exposure.

Pentax K-30 Basic Video Specs

  • 1,920 x 1,080 (Full HD / 1080p), 1,280 x 720 (720p), and 640 x 480 (VGA) recording
  • MPEG-4 AVC / H.264 compression at all resolutions; MOV file format; three quality levels
  • A choice of 29.97, 25, or 23.976 frames per second at all resolutions; for 720p mode only there's also a choice of 59.940 or 50 fps
  • Automatic or manual focus possible before or during movie capture, but only single AF operations are available while recording, not full-time AF
  • Manual focus peaking before capture starts, but not during capture
  • Optional infrared remote controls can start or stop recording; one model can also trigger AF operations remotely
  • Auto, aperture-priority, or full manual exposure, but no shutter-priority
  • Automatic or manual ISO sensitivity control in manual mode
  • Exposure compensation adjustment is available
  • Available exposure variables can be adjusted both before and during movie capture
  • Digital image stabilization supported during video recording
  • Monaural audio recording via built-in microphone on top deck
  • Five-step control over microphone levels; audio capture can also be disabled
  • Custom Image / Digital Filter functions are available in movie mode
  • Interval movie function can record timelapse movies at anywhere from one frame every three seconds to one frame per hour
  • Playback functions include the ability to split videos at up to four different points, and extract still frames

Pentax K-30 Video: Image Size, Frame Rate, and Encoding

Full HD video. The Pentax K-30 offers three resolution levels for video recording, topping out at a maximum resolution of 1,920 x 1,080 pixels (commonly known as 1080p or Full HD).

The Pentax K-30's CMOS image sensor records high definition video at a maximum resolution of 1,920 x 1,080 pixels--otherwise known as Full HD or 1080p--with a 16:9 aspect ratio. In addition, there are two lower resolution options. The 720p mode is likewise 16:9 aspect, and captures high-def video at 1,280 x 720 pixels. A standard definition mode further downsamples the video stream to produce 640 x 480 (VGA or 480p) movies with a 4:3 aspect ratio. All resolutions offer an adjustable recording rate of 29.97, 25, or 23.976 frames per second. Additionally, in the 720p mode, you can opt for rates of 59.940 or 50 fps. All resolutions and frame rates provide a choice of three quality levels, ranging from one to three stars.

Unfortunately, the Pentax K-30's 60p / 50p frame rates for 720p video seem to come at the (significant) expense of video quality. As you'll see in our samples below, videos shot at this rate look much softer than other 720p videos, even though they're shot with identical settings. They're also much more prone to moire, often producing shimmering rainbow artifacts where fine detail should be. Combined, these video quality defects were enough to persuade us to avoid using the higher frame rates, even though they do yield significantly smoother video.

Unless audio capture is disabled, all movies include PCM monaural audio. No spec is provided for the audio sampling rate, though video players report 16-bit audio at a 32 kHz sample rate, with a bit rate of 512 Kbps.

Like the K-01 compact system camera, the Pentax K-30 ditches the inefficient Motion JPEG video compression used by the earlier K-5 and K-7 SLRs in favor of MPEG-4 AVC / H.264 compression. This yields significantly smaller file sizes than in the older Pentax cameras, but also requires much greater processing power to play back or edit. The more sophisticated encoding used in the H.264 standard requires quite a bit of processor power to pull it apart and put it back together again, so frame-accurate editing of H.264 requires a fast processor and capable editing program.

The table below shows the specs for various video recording options.

Pentax K-30 Video Options
MPEG-4 H.264/AVC Format (.MOV files)
Resolution
Aspect Ratio
Frame Rate (fps)

1,920 x 1,080

16:9

29.97

25

23.976

1,280 x 720

59.940

50

29.97

25

23.976

640 x 480

4:3

29.97

25

23.976

Continuous movie recording is limited to approximately 25 minutes regardless of the capture settings, and maximum movie file size is 4GB. Pentax doesn't provide a recommended Secure Digital card speed rating to avoid issues with write speeds during video capture, but other manufacturers typically specify at least a Class 6 card, and the same is likely true with the K-30.

Here are some examples of video from the Pentax K-30, showing typical results under daylight and night conditions.

Pentax K-30: Video Samples
1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second
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1,920 x 1,080
MPEG-4 H.264/AVC, 24 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 60 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 30 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 24 frames per second
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640 x 480
MPEG-4 H.264/AVC, 30 frames per second
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1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second
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1,920 x 1,080
MPEG-4 H.264/AVC, 24 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 60 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 30 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 24 frames per second
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640 x 480
MPEG-4 H.264/AVC, 30 frames per second
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Pentax K-30 Video-Mode Focusing

For a consumer audience used to camcorders that can automatically focus during video capture (and who don't necessarily have the time and patience to learn to pull focus manually), autofocus is typically considered to be a pretty critical feature. The Pentax K-30 offers the ability to autofocus during capture, but only provides for single autofocus operations. You can trigger the autofocus system to operate before recording with either a half-press of the shutter button, or by pressing the AF button. Once recording starts, only the latter operates.

When focusing during video capture, depending on the lens in use, the audio levels, and the degree of focus adjustment required, AF noise is likely to be picked up on the audio track. With the 18-135mm DC kit lens and the K-30's internal microphone, AF noise is picked up a very faint buzz. Although we didn't have access to one during testing, SDM lenses will likely also be relatively quiet. Screw drive lenses are much louder, and their drive noise will appear in your audio very clearly as a strong buzzing/whining.

You can also manually focus the lens during a recording, and the true manual operation of AF on Pentax's K-mount lenses means you can do this more or less silently, simply by being careful about turning the focus ring. (Some interchangeable-lens cameras we've tested use "fly by wire" focusing, whereby the focus ring only instructs the camera to move the lens elements rather than moving them directly via a mechanical coupling, which can mean that small clicks can be heard on the audio track every time the focus setting is changed, regardless of how slowly you turn the focus ring. With true manual operation of its lenses, the Pentax K-30 doesn't have this problem, although it's possible that a third-party or older Pentax lenses might produce audible noise while their focus was adjusted.)

As we've noted in other SLR reviews, the good news with focusing for video is that you can get surprisingly good depth of field in video mode if the lens is stopped down, thanks to the relatively low resolution of the video image. With a pixel resolution of only 2.1 megapixels even in the Pentax K-30's 1080p Full HD video mode, images that would be unacceptably blurred as 16 megapixel still shots look perfectly fine as video frames. This not only provides greater depth of field at any given aperture, but is also more forgiving of diffraction limiting at very small lens apertures. Diffraction at small apertures means you'd usually want to avoid f/16 or f/22 for still images, but again, the results generally look perfectly fine at video resolutions. Given that you can manually specify the aperture, you may be surprised by how little focus adjustment is required when using a higher ISO sensitivity and slower shutter speed.

Pentax K-30 Video Exposure Control


Pentax K-30: Aperture Control
1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, f/4
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1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, f/29
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The Pentax K-30, like the K-01 before it, offers fully manual exposure control during shooting, as well as the Aperture-priority mode that's been found in past Pentax cameras. Unlike some competitors, there's still no Shutter-priority mode. There is, however, an optional auto / manual ISO sensitivity control in the Manual mode, effectively giving you something akin to the Shutter and Aperture Priority (TAv) mode found on Pentax's SLRs. This is great, because it lets you set both exposure variables as you choose, and the camera can adjust the sensitivity automatically to attain the metered exposure.

While the absence of shutter priority is a bit of a shame, this is still a big step forward from the video feature set of earlier K-mount DSLRs, which offered only Program or Aperture-priority modes. (The K-30 does, of course, allow Program autoexposure as well.) Interestingly, it's possible to adjust shutter speed, aperture, and ISO sensitivity during video capture, although handling noise from the controls means you can't really accomplish much with this feature unless using a separate audio capture device.

Surprisingly, the K-30's upper sensitivity limit is ISO 3,200 equivalent for video capture. We say that's surprising because the tiny Pentax Q, which has a much smaller sensor--albeit backside-illuminated--will roam as high as ISO 6,400 equivalent. (The K-01, which shares much the same sensor as the K-30, also had the same ISO 3,200 upper limit.) In Program and Aperture-priority modes, +/-2.0EV of exposure compensation is available in 0.3 EV steps, and white balance settings also carry over to video mode. (Exposure compensation is also available in Manual mode, but doesn't do anything except change the indication as to how far you are from the metered exposure, unless using Auto ISO.)

Pentax K-30: Aperture in Program Auto
1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, Program Auto showing diffraction limiting
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1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, Aperture Priority, f/5.6
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When using automatic exposure control, the Pentax K-30 will vary exposure to account for changes in ambient lighting as capture continues, although it does so fairly slowly. Still, it's better than most cameras we test in this regard. Note that it does, much like Canon's SLRs and some mirrorless cameras, tend to use very small apertures in bright daylight. That results in detail lost due to diffraction limiting, but the alternative would be to increase the shutter speed, which brings its own problems. (A faster shutter speed reduces motion blurring between frames, resulting in choppy-looking video.) And of course, with manual exposure control available, you can always choose to override the camera's chosen exposure variables if you disagree.

We did experience one quirk with exposure control in shooting video with the Pentax K-30. Shooting in Manual exposure mode with Auto ISO could result in a brief period of significant overexposure at the start of video capture, although the exposure level was correct before the shutter button was pressed. This varied anywhere from a dozen frames or so, to as much as several seconds of video.

Pentax K-30 In-Camera Image Adjustment for Movies

Catering to those who really want to express their creative side without relying on computers and complicated post-processing, the Pentax K-30 also includes some pre-capture functions that change the look of videos, in some cases quite radically.

The Custom Image effects are the more subtle, changing saturation, toning / hue, high / low-key adjustment, contrast, and sharpness, as well as filter effect for monochrome videos, to yield eleven different user-adjustable presets. These include Bright, Natural, Portrait, Landscape, Vibrant, Radiant, Muted, Bleach Bypass, Reversal Film, Monochrome, and Cross Processing.

The Digital Filter functions bring a more radical difference to the look of videos. For example, you can capture a video that's completely desaturated other than one chosen color, with the look of a film negative, or even with a quasi-fisheye effect added in software. In full, the list of Digital Filter effects in the K-30 includes Extract Color, Toy Camera, Retro, High Contrast, Invert Color, and Color. The Shading filter that's available for still images is not available in video mode. Note that Pentax states movies recorded with digital filters active may have dropped frames, likely due to the processing power required for the effects.

In addition to the filter functions, the Pentax K-30 has an unusual interval movie mode, which captures images for a preset length of time, at a preset interval. It's similar to that in the K-01, although the lowest capture rate has been changed. You can opt for an interval of 3, 5, 10, or 30 seconds, or of 1, 5, 10, or 30 minutes, and the maximum interval period of one hour. (The K-01 had a one-second rate, instead of three seconds.) The recording time can run anywhere from twelve seconds to 99 hours, although the upper limit varies with the selected interval, and so it's not possible to configure an interval movie of more than a couple of thousand frames. Interval movies play back at an accelerated rate, and don't include sound. The video can be set to start immediately that the shutter button is pressed, or at a predetermined start time. For longer clips, you'll want to use the optional K-AC128 AC adapter kit.

Pentax K-30 Video: Image Stabilization

Pentax K-30: Image Stabilization
1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, stabilized
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1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second, unstabilized
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1,280 x 720
MPEG-4 H.264/AVC, 30 frames per second, stabilized
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Although the Pentax K-30's incorporates a sensor shift-type image stabilization system, this is disabled during video recording, in favor of what Pentax calls 'Movie SR'; in essence, digital image stabilization. Unlike a mechanical system, this allows completely silent operation, but there's no such thing as a free lunch. The system works by creating the video feed from a 'window' of pixels in one particular location on the sensor, with the location of the window moved around the sensor as needed to correct for motion. For this system to function, you need to leave a band of "spare" pixels around the periphery of the sensor, and in the process, the K-30 effectively increases the effective focal length crop significantly. While for telephoto videos this may in fact be desirable, it means that if you want the widest possible field of view, you'll want to disable image stabilization.

Likely due to the manner in which it operates, the K-30's Movie SR sometimes induced a slight "wobbling" in captured videos, visible as a slight squashing / stretching along the vertical axis. This is distinct from the "jello" effect caused by rolling shutter, although the two effects can be present in a single clip, making the distortion even more pronounced. We also noted that as you reach the limits of the corrective area available by panning the sensor window, the K-30 shows "hiccups" in video playback where your subject moves significantly further than it should in a single frame. On the plus side, the system is very stable, able to correct reasonably well even for motion from walking.

Note that even if you disable Movie SR, you don't recoup the wide-angle capabilities. The crop is increased at all times when in movie mode.

Pentax K-30 Video: Audio recording

Audio recording in movies is optional with the Pentax K-30, and can be turned on or off using the Recording Sound Level function located in the Movie menu. Audio is recorded as 16-bit, 32 kHz stereo PCM, with a bit rate of 1,024 Kbps, captured via a single microphones on the top panel, directly behind the popup flash. Unlike the K-01, there's no external microphone connectivity.

Audio recorded with the K-30 sounded clear, but we do no tests to measure frequency response or sensitivity, so can't comment quantitatively. The level of hiss recorded on audio tracks in relatively quiet environments was somewhat more noticeable than we're accustomed to on competing models, however.

Unlike some of its competitors, the Pentax K-30 provides a five-step manual audio level control. Unfortunately, there's no audio level display, nor any way to monitor audio from the camera body, and so you have no way to know whether you're in the ballpark or not without playing back a recorded video. (And even then, you're going to want to listen on an external device, as the camera's internal speaker is quite weak.) Nor is there a wind cut function, something which may be slightly more of an issue for the K-30's primary target buyers; we noticed a fairly significant amount of wind noise picked up in our own clips, shot in a light breeze.

Audio capture is automatically disabled for interval movies.

Pentax K-30 Movie Recording User Interface

The Pentax K-30's movie mode can be accessed via a separate position on the camera's mode dial. Like past Pentax DSLRs, there's no dedicated Video button, so video capture is impossible unless you're in Movie mode. Instead, you start or stop capture with the regular Shutter button. The lack of a movie button is something of a shame, as this was present in the earlier K-01 compact system camera. The clear delineation between still and video capture lessens the ability to quickly grab spontaneous, unanticipated video clips, as you have to pay attention to changing the camera's operating mode before you can switch from still to video capture, or vice versa.

A few movie-specific setting adjustments are made in a dedicated Movie Menu, which has relatively few options. Other settings applicable to both still and video shooting are made in the still image menus. Options on the Movie Menu for video recording are:


Pentax K-30 Record Mode Menu Movie Options
Top-Level
Selection
Second-Level
Notes
Exposure Setting
- Program (P)
- Aperture-priority (Av)
- Manual (M)
Manual mode allows Auto or manual ISO; other modes use Auto ISO.
Movie Capture Settings
- Recorded pixels
- Framerate
- Quality level
Recording Sound Level
- Five steps or off
Movie SR
- On
- Off
Interval Movie
- Interval
- Recording time
- Start interval
- Start time



Rolling Shutter Artifacts

Pentax K-30: Rolling Shutter Artifacts
1,920 x 1,080
MPEG-4 H.264/AVC, 30 frames per second
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1,920 x 1,080
MPEG-4 H.264/AVC, 24 frames per second
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1,280 x 720
MPEG-4 H.264/AVC, 60 frames per second
Download Original
1,280 x 720
MPEG-4 H.264/AVC, 30 frames per second
Download Original
1,280 x 720
MPEG-4 H.264/AVC, 24 frames per second
Download Original
640 x 480
MPEG-4 H.264/AVC, 30 frames per second
Download Original

Essentially every video capable digital SLR/CSC currently on the market exhibits some level of motion-related distortion called rolling shutter artifacts. These are caused because the image data is captured and then read off the chip sequentially by rows, rather than each frame's data being captured all at once. In the case of the Pentax K-30, this means that image data for the last row of a given frame is captured and read out as much as 1/24th second after the data for the top row was captured. The effect on moving objects is like that of a focal plane shutter in an SLR, but more pronounced, because the video frame is read out much more slowly than the slit of a focal plane shutter moves across the sensor.

For a camera that scans video frames vertically (as all do that we're aware of), rolling shutter artifacts will be most noticeable for subjects that are moving rapidly side to side, or when the camera itself is being panned horizontally. Verticals in the scene will appear tilted to the right or left, depending on the direction of camera motion. As an example, consider the case of a camera being panned from left to right, with a flagpole or other vertical object in the middle of the scene when recording for a particular frame begins: If the top of the object was centered horizontally when the first line of the video frame is acquired, by the time the last line of the frame has been captured, the bottom of the object will have shifted to somewhere left of center: As a result, the vertical object would appear to be leaning to the right.

Compared to other recent SLRs, rolling shutter artifacts from the K-30 were relatively minimal.

Computer Requirements for Viewing HD Video

A typical computer these days has little trouble dealing with still images, but high-definition video can be another matter. Depending on the file format involved, it can take a pretty beefy computer to handle HD-resolution video playback without stuttering or dropping frames. The MPEG-4 H.264/AVC image compression used by the Pentax K-30 is a fairly compute-intensive format, and its high maximum resolution of 1,920 x 1,080 pixels resolution means there's a lot of data in each frame to deal with. The net result is that you'll need a reasonably recent computer to play the K-30's Full HD video files smoothly, and will want a pretty powerful machine for Full HD video editing.

You can view your movies on a TV via the combined USB / AV output, but there's no high-definition video output. Note that an AV cable is not included in the product bundle.

 



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