Panasonic G3 Video

Panasonic G3 Video Recording

Panasonic pioneered advanced video capability in compact SLD (Single Lens Direct-view) cameras, in that their DMC-GH1 was at the time the only interchangeable-lens camera with truly effective "live" autofocus during video recording. That capability has been shared by subsequent Panasonic models (and is now becoming more common in competitors), but full capability still does depend on the exceptional AF speed of their special "video-capable" lenses, all of which carry the "HD " video support marking. There are now three HD-badged lenses: the 14-140mm zoom that shipped with the GH1, as well as two recently-announced power zoom models, the PZ 14-42mm and 45-175mm, both of which feature fly-by-wire rocker-style zoom and focus controls.

With slower-focusing lenses, the new Panasonic DMC-G3 may not be able to track motion as well, and the motors in some lenses may be audible in the sound track, but the Panasonic G3 generally does a better job of focus tracking during video than many of its competitors. (And of course, you're always free to focus manually, if you'd like to guide the viewer's attention more directly.)

While it doesn't provide the full PASM exposure control of the earlier GH1, it does offer at least some control over shutter speed. The Panasonic G3 offers interlaced 1080i (aka Full HD) video recording, as well as a selection of lower-resolution modes. Unlike most of its competition, it also provides both a microphone levels adjustment function, and an on-screen levels display. There's also a wind cut function that aims to remove untoward noise from captured video, and a selection of Photo Style and Creative Control modes plus the ability to manually controls contrast, shaprness, saturation, and noise reduction. The most significant limitations for video enthusiasts will be the lack of aperture control, and the ability to connect an external microphone to the camera.

While it may not provide the level of exposure control demanded by pros and high-end video enthusiasts, we believe the Panasonic G3 offers quite a compelling package of video features for the average consumer, a group more likely to desire features such as the continuous autofocus capability, especially given the relatively smooth focus tracking ability.

Panasonic G3 Basic Video Specs

• Interlaced 60 fields-per-second Full HD / 1080i (1,920 x 1,080) or progressive scan 60 frames-per-second 720p (1,280 x 720) high-def recording, but derived from 30 fps sensor output (50 fields / frames per second in Europe, derived from 25 fps sensor output)
• 640 x 480 or 320 x 240 at 30 fps SD recording
• Option of either AVCHD (720p or higher) or Motion JPEG (720p or lower) recording formats
• Autofocus is possible during recording, with variable results depending on the lens used (best results with 'HD'-branded lenses)
• Programmed-only exposure (that is, no true aperture-priority or shutter-priority, nor manual)
• Flicker Reduction does let you choose shutter speeds of 1/50, 1/60, 1/100, 1/120 second, providing (very) limited shutter control. (As the name suggests, this is intended primarily for avoiding video flicker from fluorescent lights.)
• EV adjustment is available in all movie recording modes, but can't be adjusted during recording.
• Stereo audio recording via built-in microphone.
• Up to eight full-resolution or 30 two-megapixel resolution still images can be captured during each video recording session. Full-res images interrupt capture, low-res images cause no interruption.
  
  

Panasonic G3 Video: Image Size, Frame Rate, and Encoding

The Panasonic G3 records a variety of resolutions and frame rates, using either the more space-efficient AVCHD or the more broadly compatible Motion JPEG file formats. The capture rate for AVCHD movies is always 60 fields per second at 1080i or 60 frames per second at 720p in the US and 50 fields / frames per second in Europe, but note that, regardless of the capture rate, the sensor is capturing at 30 or 25 fps respectively, and the additional frames are created by interlacing or doubling the frames coming from the sensor. In Motion JPEG mode, a rate of 30 frames per second is always used, matching the sensor rate. No spec is provided for the sampling rate of the audio track during movie recording, though video players report 16-bit PCM audio at 16 kHz for Motion JPEG, and 48 kHz AC-3 Dolby Digital at 192 kbps for AVCHD.

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

As noted above, the Panasonic G3 offers two video recording formats, either the HD-only AVCHD format or the less space-efficient but more computer-friendly Motion JPEG. The Motion JPEG file format is much less efficient in its use of memory card space, but is more easily read by older computers. AVCHD is the best choice if your primary output is going to be directly to a HD television, but Motion JPEG will be easier for many computers to read, particularly if they're more than a couple of years old. (As you can see from the table above, though, Motion JPEG files take up quite a bit more space for a given pixel resolution.)

In AVCHD mode, two resolutions are available, but both offer the same bit rate of 17 Mbps (megabits per second), so essentially you're trading compression level versus resolution. No lower compression levels are offered, but that's not necessarily a negative. In our experience with cameras recording in the AVCHD format, we've generally found that the video artifacts associated with quality settings below 17 Mbps generally weren't worth the savings in file size anyway. Note that Panasonic doesn't include a switchable video output mode in North American cameras, but those intended for sale in other markets may allow a choice of either NTSC or PAL video encoding. For NTSC mode, AVCHD files generated by the G3 are always recorded at a rate of either 60 fields-per-second interlaced for 1080i, or 60 frames per second progressive-scan for 720p, but the source data provided by the sensor is read off at a rate of 30 frames per second. If a PAL mode is available, then when set to this, the 60 fields / frames per second rates are replaced with 50 fields / frames per second rates, deriving from 25 frames per second sensor data.

Motion JPEG offers a choice of three file sizes, as detailed in the table above, all recorded at 30 frames/second, with the sensor capturing data at that same rate. Due to its higher data rates, Panasonic cautions in the manual that Motion JPEG recording requires at least a Class 6 SD memory card, while AVCHD needs a speed rating of only Class 4.

The Panasonic G3's 30 fps sensor output is faster than some cameras that are limited to the 24 frames/second "cinema" standard, but it doesn't match the level of smoothness and motion-capture ability offered by models sporting 60 frames/second sensor output. In both frame rate and resolution, it ranks roughly in the middle of the pack of current interchangeable-lens video-capable cameras. (Although some people prefer or need the 24 fps standard, either for its more "film-like" look, or because they're pros who need to mix their videos in with other clips shot on film.)

Panasonic G3 Sample Videos

Here are some examples of video from the Panasonic DMC-G3, showing typical results under daylight and night conditions.

Panasonic G3 Video-Mode Focusing

As with the G2 and GH/GF-series cameras before it, consumers will doubtless find the Panasonic G3's live autofocus during recording an important feature. Pros and advanced amateurs can "pull focus" (adjust the focus manually) while filming video, and indeed may well prefer to do so, considering focus to be another means of expressing their artistic vision. Doing it well is very much a learned skill, though, and something few people ever learn to do really well. Without live AF, consumers for the most part are reduced to only shooting subjects at a constant distance from the camera, or to having to settle for a lot of poorly-focused video. A lot of video-capable SLRs are certainly being sold to consumers these days, and having some video capability is certainly better than none, but for most consumers to make full use of a video camera, it really needs to be able to focus on the fly.

As I noted in our review of the Panasonic GH1, the Panasonic engineers really had video recording in mind from the very beginning of Micro Four Thirds development. As a result, Panasonic SLD cameras have offered uncommonly capable video-mode focusing, and the G3 is no exception. For the most responsive video focus-tracking, you'll need a special video-specific lens, badged with "HD" video support branding. Three such lenses are now available: the Lumix G Vario HD 14-140mm f/4.0-5.8 Asph. Mega O.I.S. zoom lens that shipped with the GH1, as well as two recently-announced power zoom models, the Lumix G X Vario PZ 14-42mm f/3.5-5.6 Asph. Power O.I.S., and the Lumix G X Vario PZ 45-175mm f/4.0-5.6 Asph. Power O.I.S. The latter two lenses also feature a control design aimed at video use, with fly-by-wire rocker-style zoom and focus controls, rather than the more traditional ring-style controls with a direct mechanical connection.

Although we've not yet tested production versions of the power zoom lenses, we tried out the 14-140mm model when we reviewed the GH1, and found that with it, that camera did a surprisingly good job tracking moving subjects. While it didn't do a 100% perfect job of tracking the action, it stayed pretty darn close most of the time, managing about as well as a typical consumer camcorder, and well within the limits of what we'd find acceptable for casual video snapshots and family memory-recording. You could see the focus system hunting a bit here and there, but it wasn't nearly as pronounced as we've seen in some competing models, and for the most part wasn't very noticeable when the movie was playing. Overall, we felt it to be a very practical video AF system for consumer movie recording, and since the G3 clocks data off the sensor at the same rate, but has a newer Venus Engine FHD processor with one additional core compared to the Venus Engine HD used in the GH1, we'd expect equal or better performance here. (But with that said, we didn't have an "HD"-badged lens at the same time as our G3 camera body, and so this is somewhat speculative. With the 14-42mm kit lens, focus operation is still pretty quiet, but nowhere near as fast.)

We continue to find that we appreciate Panasonic's touch-select movable focus point in the G3 as much or more for video recording than we did when shooting still images. We've honestly never been particularly big fans of touch-screen interfaces on cameras, but the way Panasonic implemented theirs on the is very fluid and natural, and really makes a lot of sense. We especially liked that we could use the touch-select focus to change the point of focus in the frame while video recording was in progress, at least with the AF control set to the 23-point option: We could start with the camera focused on a foreground object on one side of the frame, and then have it transition smoothly to focusing on a background object on the other side of the frame, simply by touching the other side of the LCD screen. The advantage of this is that our finger caused no noise on the audio track, other than the operation of the focus motor itself. This is a nice contrast to systems where shifting the focus would require either manual manipulation of the lens or pressing buttons on the camera's user interface, either of which would produce clearly audible noise on the audio track. The newer Power Zoom lenses promise to make things even better, with a gentle push on two rocker control making shake- and (handling) noise-free adjustments to either focus or zoom position even easier, and allowing variable speed on both controls.

Panasonic G3 Video Exposure Control

While the Panasonic G3 lets you record movies directly from any of its still-image exposure modes, including aperture-priority, shutter-priority, and full manual exposure modes, the shutter speed, aperture, and ISO settings for video recording are always automatically controlled. Thus, while the controls might suggest full PASM (programmed, aperture-priority, shutter-priority, and full manual exposure) exposure control for videos, no direct control over lens aperture is available, and nor is full control over shutter speed, although at least a little control is available in this area. An option on the third page of the Motion Picture menu enables or disables Flicker Reduction, which lets you choose shutter speeds of 1/50, 1/60, 1/100, and 1/120 second for movie recording. These are intended to help in controlling video flicker caused by fluorescent lighting, but can also be used to gain at least a measure of direct control over shutter speed.

In addition to the conventional exposure modes, the Panasonic G3 offers many of its still-image scene modes for video recording as well. Video-capable scene modes include Portrait, Architecture, Food, Party, Soft Skin, Sports, Objects, Sunset, Scenery, Flower, and Low Light. Scene modes that are restricted to still photo use only include Night Portrait, Baby 1, Baby 2, Night Scenery, Pet, Peripheral Defocus, and Illuminations.

The Creative Control function is available for both stills and movies, and offers sub-options of Expressive, Retro, High Key, Sepia, and High Dynamic. Photo Styles also apply to both stills and videos, and options here include Standard, Vivid, Natural, Monochrome, Scenery, Portrait, and a Custom option which lets you adjust Contrast, Sharpness, Saturation, and Noise Reduction levels to your liking.

Panasonic G3 Movie-Mode Image Stabilization

Panasonic's image stabilization technology is lens-based, so IS effectiveness and impact on the audio track will depend on the lens you're using. We felt that the 14-42mm kit lens's IS worked well, and had relatively little impact on the audio, but we could definitely hear it working in quiet passages: When recording in quiet settings, you'll probably want to turn it off, but it's still quieter than typical body-based IS systems.

Panasonic G3 Video: Audio recording

Like most competing SLR/SLD cameras with video recording capability, especially those aimed at consumers, the Panasonic G3 can record audio only via its internal microphone, with no provision for external audio recording. To sidestep this limitation, many amateur videographers simply use a separate, inexpensive digital audio recorder to record a separate soundtrack, which they then synchronize with the audio from the camera in their editing software. Software synchronization of audio tracks gives essentially perfect alignment of the video and externally-recorded video with relatively little effort.

The G3 is relatively rare, though, in being able to provide not only for manual audio level control, but also an on-screen stereo levels display that lets you see if you need to adjust the levels to correctly capture your subject. It's perhaps not the finest-grained control, as the microphone level is controlled in four arbitrary steps, but nonetheless this is more than is offered by most competing cameras, especially if one excludes SLRs aimed at professional use. The on-screen levels display offers an eight-step indication for each channel, meanwhile.

Panasonic doesn't publish specs for the G3's audio recording capability, but video players report 16-bit PCM audio at 16 kHz for Motion JPEG, and 48 kHz AC-3 Dolby Digital at 192 kbps for AVCHD. Audio recorded with the camera's internal mic seemed plenty clear, but we do no tests to measure frequency response or sensitivity. We did notice that there was audible hiss in audio tracks recorded with the in-camera mic in very quiet environments. On a positive note, though, we didn't hear any audible "breathing" from the auto-gain system adjusting sensitivity as sound levels got louder or softer.

Panasonic G3 Movie Recording User Interface

The Panasonic G3 makes movie recording very easy, as you can initiate it at any time, regardless of the mode-dial setting: Simply press the prominent Movie Record button with the red dot at its center on the G3's rear panel, and the camera will start recording video. Video resolution and file format are available via the rear-panel LCD or electronic viewfinder, and you can change these settings at any time via the Quick menu or Motion Picture menu, using either the touch interface or physical buttons. The result is a camera that feels like it was intended to shoot video from the start, rather than one with movie recording grafted on as an afterthought. The quick access to video recording makes it much more likely that you'll use the Panasonic G3 to record little "video snapshots," rather than it being a big production to switch in and out of video mode.

We've generally favored use of the shutter button to start and end video recording, but found ourselves really liking the convenience of the G3's dedicated record button. Having it on the rear panel, right behind the shutter button also made it very quick to access with our thumb, so our index finger could remain on the shutter button at all times, ready to capture a spontaneous still image. The touch screen was also nicely integrated into the video recording interface; we found it especially handy for moving the focus point, and used the Quick Menu quite a bit for changing the video recording mode and/or resolution.

One thing to be aware of in recording movies is that the aspect ratio can change immediately that capture starts, if the video and still-capture mode options are set differently. This can be a little disconcerting the first few times it happens. The solution is to either just learn to expect it, or to check ahead of time to see that you're using the same aspect ratio for both still and video capture. There is an option in page five of the Custom menu that determines whether the G3 should default to showing the aspect ratio set for still or movie capture on its LCD and EVF, so if you predominantly shoot one or other media type, you can at least ensure you're surprised as seldom as possible.

A much larger issue is that we discovered there to be a combination of significant lag and anticipation (for lack of a better word) when starting/stopping movie recording. When starting a recording, we found that the recording didn't start until about a second after pressing the Movie Record button. While we haven't tracked this "movie shutter lag" with other cameras, we've seen varying amounts of delay in the video-capable SLR/SLD cameras we've tested in this regard. Somewhat more disconcerting, though was that, as we've seen in some past Panasonic models, the G3 stopped recording early, with the end of the recorded video coming about a half-second before the point at which we'd pressed the Movie Record button to stop it. This was rather odd in our experience, and led to us chopping off a number of video clips short, ending them before we intended to.

An unusual feature of the Panasonic G3 is its ability to capture up to still images while a video recording is ongoing, simply by pressing the shutter button whenever you want to grab a frame. There are two modes in which this can operate. In the first, up to 30 captured frames are held in the camera's memory until you're done recording, being saved to the memory card once the recording has finished, and these in-movie still images are limited to 2-megapixel resolution. What's nice is that grabbing them doesn't pause or otherwise interrupt the video recording. You will, however, very clearly hear clicks from the actuation of the shutter button in the movie's audio track. At only 2 megapixels, you won't be making posters with these shots, but there's plenty of resolution to make decent 4 x 6 inch prints. The resolution of these still images is actually 1,920 x 1,080 pixels, matching the maximum resolution of the Panasonic G3's recorded video.

In the second mode of operation, the images are captured at full resolution, but the movie recording is stopped during still image capture. In this instance, the movie itself is interrupted briefly, and the audio capture halts, leaving what appears as a brief pause on a still image in the video at the point where recording temporarily halted. Simultaneous still/movie recording is also not available when the resolution is set to VGA or QVGA in Motion JPEG mode. That makes sense when set to record two megapixel stills, since the video stream itself is of lower resolution, but curiously the limitation also applies when saving full-res stills with an interruption to the video stream.

Setting adjustments in movie mode are made via the Motion Picture Menu, which for convenience shares a few items with the main Record Menu. A full list of options can be found on the Modes and Menus page.

Rolling Shutter Artifacts ("Jello Effect")

Essentially every video capable digital SLR/SLD currently on the market exhibits motion-related distortions called rolling shutter artifacts. These are caused because the image data is captured and then read off the chip sequentially by rows, rather being captured all at once. In the case of the Panasonic, this means that image data for the last row of a given frame is captured and read out anywhere from 1/25th to 1/30th second after the data for the top row was captured. The effect on moving objects is similar to 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.

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 Panasonic G3 supports both AVCHD and Motion JPEG recording formats. The AVCHD format is much more space-efficient on the memory card, and displays well on HD television sets, but is one of the more compute-intensive formats, and its 1,920 x 1,080 (1080i) resolution means there's a lot of data in each frame to deal with at full resolution. The net result is that you'll want a relatively recent and powerful computer to play full-res high-def video files from the G3 on your computer. At lower resolutions, and for Motion JPEG video, the requirements will be more modest. You can, of course, view your movies on an HDTV via the Type-C Mini HDMI output.