Panasonic GH2 Video Recording

Panasonic pioneered advanced video capability in Compact System Cameras (CSCs), in that their DMC-GH1 led and still leads the way in many respects. Apart from Sony's SLT series, Panasonic's Micro Four Thirds models are the only interchangeable-lens cameras with autofocus during recording fast enough to be called truly "live." According to Panasonic, a faster processor in the GH2 reduces its focus-lock time to as little as 0.099 second, down from the 0.2 second of the GH1. As was the case with the GH1, the Panasonic GH2's video prowess is also assisted by its image-stabilized 14-140mm kit lens, which is equipped with a special high-speed and nearly-silent autofocus motor and continuously variable lens aperture. The combination is a uniquely effective and a highly compact camera system for shooting high-definition video.

Also in common with the previous GH1, the Panasonic Lumix GH2 offers full PASM exposure control while recording video, a feature shared by surprisingly few video-capable SLRs. Unlike some of its competition, the Panasonic GH2 also provides a stereo microphone jack for connecting to an external microphone; either Panasonic's own DMW-MS1 model or a third-party unit with compatible signal levels. Alone among the G-series models, the Panasonic GH2 can also shoot at full 1080i HD resolution. (Other the the GH1 which it replaces, Panasonic's other G-series models topped out at 720p resolution.) In another nod to high-end video enthusiasts, the Lumix GH2 now offers full AVCHD recording at the maximum 24 Mbps the standard supports. (The GH1 maxed-out at 17 Mbps.)

Panasonic GH2 Basic Video Specs

• 1080i (1,920 x 1,080), 60 fields/second HD recording, derived from 60 fps sensor output (50 fields/second in Europe, derived from 50 fps sensor output)
• 720p (1,280 x 720), 60/50p HD recording, also derived from 60/50 fps sensor output
• 848 x 480, 640 x 480, 320 x 240 at 30p SD recording
• High-quality "Cinema" video mode gives 1,920 x 1,080 at 24p, with higher 24 Mbps AVCHD quality
• Option of either AVCHD or Motion JPEG recording formats
• Autofocus is possible during recording, with variable results depending on the lens used (live AF tracking is excellent with the 14-140mm kit lens)
• True aperture-priority, shutter-priority, and full-manual video exposure options
• Full ISO control in all Movie exposure modes
• EV adjustment is available in all movie recording modes, and can be adjusted during recording.
• Stereo audio recording via built-in microphone, plus external stereo input via 2.5mm phone jack.
• Up to 30 two-megapixel resolution still images can be captured during each video recording session, without pausing the recording (when recording is started from a still-image capture mode).
• Up to 8 full-resolution still images can be captured per video recording session, but the video is paused briefly for each (also available only when recording is begun from a still-image capture mode).
• Slow-motion recording at 0.8x normal speed, fast-motion recording at 1.6x, 2x and 3x normal speed
  
  

Panasonic GH2 Video: Image Size, Frame Rate, and Encoding

Panasonic GH2 Video Resolutions & Recording Formats

The Panasonic GH2 records a variety of resolutions and frame rates, using either the more space-efficient AVCHD or the more broadly compatible Motion JPEG file formats. Depending on the video mode selected, the frame rate is either 24p or 60i in the US and 24p or 50i in Europe, but note that, while the frame rate for standard AVCHD recording is 60 or 50 fields per second in the files, the sensor is capturing at 60 or 50 frames per second respectively. That's quite an improvement over the GH1's 24 or 25 frames per second sensor output at Full HD. A special Variable Movie mode lets you record at 0.8x (slow motion) and 1.6x, 2x, or 3x (fast motion) frame rates. 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 Dolby AC3 audio at 48 KHz sample rate and 192 Kbps bit rate for AVCHD.

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

Panasonic Lumix DMC-GH2 Video Options
AVCHD Format (.MTS files)
Menu Designation	Resolution	Frame Rate	Card Capacity (approximate)
24H	1080p 1,920 x 1,080	24 fps 24 Mbps	3 MB/second (10 minutes on 2GB card)
24L	1080p 1,920 x 1,080	24 fps 17 Mbps	2.1 MB/second (13 minutes on 2GB card)
FSH	1080i 1,920 x 1,080	60 fields/s (sensor output is 60 fps) 17 Mbps	2.1 MB/second (13 minutes on 2GB card)
FH	1080i 1,920 x 1,080	60 fields/s (sensor output is 60 fps) 13 Mbps	1.6 MB/second (17 minutes on 2GB card)
SH	720p 1,280 x 720	60 fps (sensor output is 60 fps) 17 Mbps	2.1 MB/second (13 minutes on 2GB card)
H	720p 1,280 x 720	60 fps (sensor output is 60 fps) 13 Mbps	1.6 MB/second (17 minutes on 2GB card)
Motion JPEG Format (.MOV files)
Menu Designation	Resolution	Frame Rate	Card Capacity (very approximate)
HD	1,280 x 720 (16:9 aspect ratio)	30 fps	~~3-4 MB/second (~7.3 minutes on 2GB card)
WVGA	848 x 480 (16:9 aspect ratio)	30 fps	~~1-2 MB/second (~18.5 minutes on 2GB card)
VGA	640 x 480 (4:3 aspect ratio)	30 fps	~~1-1.5 MB/second (~19.2 minutes on 2GB card)
QVGA	320 x 240 (4:3 aspect ratio)	30 fps	~~0.5 MB/second (~53.3 minutes on 2GB card)

As noted above, the Panasonic GH2 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 your computer to read, particularly if it's more than a few years old. (As you can see from the table above, though, Motion JPEG files take up quite a bit more memory-card space for a given pixel resolution.)

In AVCHD mode, the pixel resolution can be either 1,920 x 1,080 or 1,280 x 720, and the compression also varies depending on the quality level selected. In both FSH and FH modes, the resolution is 1,920 x 1,080 (interlaced), but the bitrate is 17 Mbps and 13 Mbps respectively. As noted earlier, the AVCHD files in these modes are recorded at a 60 fields/second in NTSC or at 50 fields/second for the PAL video spec, but the data is actually read from the sensor at 60 and 50 frames/second respectively. SH and H modes are both 1,280 x 720 (progressive scan), at 60p or 50p and the bitrates again are 17 and 13 Mbps. They are compatible with the trimmed-down AVCHD Lite spec that has been used on other Panasonic G-series models. 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.

The Lumix GH2 goes beyond earlier models, though, in offering the 24 Mbps quality level of the full AVCHD spec in its 24 fps 1,920 x 1,080p (progressive scan) "Cinema" mode. There, the 24H mode is saved at 24 Mbps, while the 24L mode is saved at 17 Mbps. The combination of the lower 24 fps frame rate and higher 24 Mbps recording bitrate makes for very clean video imagery, with better resistance to compression and motion artifacts, and better detail preservation when panning.

Motion JPEG offers a choice of four resolutions, as detailed in the table above, all recorded at 30 frames/second with the sensor capturing data at that same rate (PAL mode is not offered, since Motion JPEG is designed for computers). 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. Videos can be recorded continuously up to 29 minutes and 59 seconds, though Motion JPEG format has a 2GB file size limit.

Here are some examples of video shot with our test sample of the Panasonic DMC-GH2:

Panasonic GH2 Video Samples
AVCHD	Motion JPEG
FSH 1,920 x 1,080i, 60 fields/s, 17 Mbps View on Vimeo | Download Original (11 seconds, 22.2 MB)	HD resolution 1,280 x 720p, 30 fps View on Vimeo | Download Original (11 seconds, 36.9 MB)
FH 1,920 x 1,080i, 60 fields/s, 13 Mbps View on Vimeo | Download Original (12 seconds, 18.1 MB)	WVGA resolution 848 x 480p, 30 fps (no example)
24H 1,920 x 1,080p, 24 fps, 24 Mbps View on Vimeo | Download Original (11 seconds, 29.8 MB)	VGA resolution 640 x 480p, 30 fps View on Vimeo | Download Original (11 seconds, 15.0 MB)
24L 1,920 x 1,080p, 24 fps, 17 Mbps View on Vimeo | Download Original (13 seconds, 25.6 MB)	QVGA resolution 320 x 240p, 30 fps (no example)
SH 1,280 x 720p, 60 fps, 17 Mbps View on Vimeo | Download Original (11 seconds, 21.3 MB)
H 1,280 x 720p, 60 fps, 13 Mbps View on Vimeo | Download Original (13 seconds, 19.7 MB)
Panasonic GH2 Night Video Samples
AVCHD	Motion JPEG
FSH 1,920 x 1,080i, 60 fields/s, 17 Mbps View on Vimeo | Download Original (12 seconds, 23.9 MB)	HD resolution 1,280 x 720p, 30 fps View on Vimeo | Download Original (12 seconds, 46.8 MB)
FH 1,920 x 1,080i, 60 fields/s, 13 Mbps View on Vimeo | Download Original (12 seconds, 18.7 MB)	WVGA resolution 848 x 480p, 30 fps View on Vimeo | Download Original (12 seconds, 16.0 MB)
SH 1,280 x 720p, 60 fps, 17 Mbps View on Vimeo | Download Original (12 seconds, 23.1 MB)	VGA resolution 640 x 480p, 30 fps View on Vimeo | Download Original (12 seconds, 15.7 MB)
H 1,280 x 720p, 60 fps, 13 Mbps View on Vimeo | Download Original (12 seconds, 18.4 MB)	QVGA resolution 320 x 240p, 30 fps View on Vimeo | Download Original (12 seconds, 6.4 MB)
Aperture control - 50mm, f/5.5 1,280 x 720p, 30 fps, MJPEG View on Vimeo | Download Original (5 seconds, 13.2 MB)	Aperture control - 50mm, f/22 1,280 x 720p, 30 fps, MJPEG View on Vimeo | Download Original (6 seconds, 21 MB)

Panasonic GH2 Video-Mode Focusing

As with the other G-series models that went before it, consumers will doubtless find the Panasonic GH2'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 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 their Micro Four Thirds development. As a result, the majority of Panasonic Compact System Cameras have had an edge in video-mode focusing, and the GH2 is no exception. For the most responsive video focus-tracking, you'll need a special video-specific lens, such as the 14-140mm model that's the GH2's kit lens: The lens has to have a very responsive AF motor to be able to complete an AF cycle within the 1/60 second readout cycle of the GH2's sensor. With a more powerful internal processor, the GH2 is able to achieve focus lock even quicker than the GH1, which was no slouch. The crops below show how well the Panasonic GH2 did tracking the official IR mascot Charlotte, as she retrieved a frisbee. The tracking wasn't 100%, but the GH2 did quite well; in the worst case it took only about a second for the AF to catch up with Charlotte, and for most of the video, it was never more than a half second or so from focus lock - This despite her being such a difficult subject to follow. (Her bounding motion and the fine detail of her fur are a nightmare for contrast-detect autofocus systems, but the GH2's did surprisingly well.)

Panasonic GH2 Video: Autofocus Tracking Shot with 14-140mm kit lens
This was a tough test, as Charlotte started and ended her run only a couple of feet from the camera, so the focal distance changed very rapidly at both ends of the clip. The shot was taken with the 14-140mm lens set to 50mm, the equivalent of a 100mm lens on a 35mm camera.	West end of a doggie heading east... This crop is taken 40 frames from when Charlotte started running. Here (about 0.67 second after she took off), the AF system is just about to catch up with her. Not bad at all for contrast-detect AF; this is quite a shift in focus to cover in less than 0.7 second.
Six frames (0.1 second) later, though, the camera's AF system has overshot somewhat: Note that the background is now sharp, while Charlotte is out of focus.	Just 9 frames later, though, the GH2 had largely corrected for its overshoot. She was only out of focus for a couple tenths of a second. Once again, pretty impressive tracking performance, with a very difficult subject.
Here Charlotte's heading back towards the camera, and is out from some shadows that covered her as she made the turn. She's running full-tilt, but is still quite a ways from the camera, so the GH2's autofocus system is having no trouble tracking her.	A bit less than a second later, Charlotte's getting pretty close, and the AF system is just starting to lose her: She's sharp in this frame, but following ones are noticeably out of focus.
Like I said, Charlotte started and ended her run very close to the camera. This frame is about 1.7 seconds from the point at which the AF started to lose tracking, but as you can see, this is so close its almost a macro shot.	Waiting for the next toss... We were quite impressed with the Panasonic GH2's AF tracking: With all her bounding up and down and her mottled coat, Charlotte's a very tough subject for an autofocus system to handle, yet the GH2 did very well here. With human subjects with more sharply-defined details (clothing against skin and bolder patterns on the clothing itself), the GH2 should have no trouble at all.
AF tracking, 50mm, small AF spot 1,280 x 720p, Motion JPEG View on Vimeo | Download Original (12 seconds, 54.5 MB)
AF tracking examples, AVCHD
14mm, small AF spot 1,920 x 1,080i, 17 Mbps View on Vimeo | Download Original (13 seconds, 20.2MB)	14mm, normal AF spot 1,920 x 1,080i, 17 Mbps View on Vimeo | Download Original (12 seconds, 18.9MB)
50mm, small AF spot 1,920 x 1,080i, 17 Mbps View on Vimeo | Download Original (15 seconds, 23.5 MB)	50mm, normal AF spot 1,920 x 1,080i, 17 Mbps View on Vimeo | Download Original (15 seconds, 24.1MB)

The above 1:1 crops were all taken from Motion JPEG frames captured at 720p resolution (1,280 x 720 pixels) to give a clearer image than would have been the case with the interlaced 1080i signal. As you can see, while the camera didn't do a 100% perfect job of tracking the action, it stayed very close most of the time, and caught up very quickly any time it lagged behind or overshot: It's possible that some dedicated camcorders might do better, but we felt that this was well within acceptable limits for casual video snapshots and family memory-recording. (And pro video types are more likely to pull focus manually than rely on an autofocus system, anyway.) The camera obviously lagged the action a bit at the end of the clip, when Charlotte was so close to the camera. It also had a little trouble when she first started running away from the camera, but that's quite to be expected with a bounding, furry subject like this, particularly starting and ending so close to the camera: We expect that a human subject with clear patterns in their clothing and less up-and-down motion would pose little problem for the GH2's AF system. All in all, a pretty impressive performance for live contrast-detect autofocus.

Panasonic GH2 Video: Rapid focus shift
We really liked the Panasonic GH2's touch-controlled autofocus; it made it very easy to shift the focus point during movie recording. In this clip, I alternately touched the background and the foreground flower to shift focus back and forth. Here's a shot with the background in focus.	Here's the foreground flower in focus, after touching it. The time interval between this image and the one on the left was about 0.5 second.
Focus Shift, 50mm, ~1 foot - 40 feet 1,280 x 720p, Motion JPEG View on Vimeo | Download Original (17 seconds, 22.8 MB)

We also found that we appreciated the Panasonic GH2's touch-select movable focus point as much or more for video recording as we did when shooting still images: We've honestly never been big fans of touch-screen interfaces on cameras, but the way Panasonic implemented theirs on the GH2 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, in any of the available AF modes: 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 all-but-inaudible 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.

Bottom line, the Panasonic GH2 is a great "hybrid" video/still camera. Usable autofocus tracking during video recording is a big deal for consumers. Video-capable SLRs and CSCs with non-tracking AF are certainly a long ways ahead of non video-capable models when it comes to recording family memories and other amateur video, but truly workable tracking autofocus will result in less frustration and more recorded memories for mass-market users.

Panasonic GH2 Video Exposure Control

While the Panasonic GH2 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 automatically controlled unless you start from the video-recording mode itself. Thus, while the still-image controls might suggest full PASM (programmed, aperture-priority, shutter-priority, and full manual exposure) exposure control for videos, the only way to control movie mode exposure parameters directly is to set the camera's command dial set to the movie mode setting and then select A, S, or M exposure mode from the movie mode quick menu or main menu screen.

Panasonic GH2 Video: Depth of Field Control
The Panasonic GH2 offers full exposure control (aperture, shutter speed, and ISO setting) during video recording, a pretty rare feature in its price class. Here's a crop from a video shot with the kit lens set to 50mm and an aperture of f/5.5.	Here's essentially the same shot as the one at left; this time at f/22. (The foliage in the background is quite distant; perhaps 30-40 feet, vs the flower at only a foot or so.) Because the Panasonic GH2's fast autofocus is based on contrast detection, it has no problem focusing at tiny apertures like this. (By comparison, fast phase-detect autofocus as in Sony's SLT series is only available at relatively large apertures.)

In addition to the conventional exposure modes, the Panasonic GH2 offers many of its still-image scene modes for video recording as well. Available options include SCN mode (with its sub-options of Party, Baby 1 & Baby 2, Pet and Peripheral Defocus), Portrait, Scenery, Sports, Close-up, Night Portrait, and My Color modes. The My Color mode offers sub-options of Expressive, Retro, Pure, Elegant, Monochrome, Dynamic Art, Silhouette, and Custom, which lets you adjust Color (from red to blue), Brightness, and Saturation to your liking.

Panasonic GH2 Movie-Mode Image Stabilization

Panasonic's image stabilization technology is lens-based, so IS effectiveness and impact on the audio track will depend entirely on the lens you're using. In the case of the Lumix GH2's excellent 14-140mm kit lens, we were completely unable to detect any sign of the IS system's operation in the audio, and found the image stabilization very effective as well. Very impressive!

Panasonic GH2 Video: Audio recording

Like most competing SLR/CSC cameras with video recording capability, the Panasonic GH2 can record audio via its internal microphone. Unlike many competing models, though, the built-in mic records in stereo, and the camera also includes an input jack for an external stereo microphone, hidden under a rubber flap on the left side of the body (as viewed from the rear). This is a big bonus for serious video users, as an external mic jack lets you avoid the inevitable noise on the audio track whenever you move your hands on the camera body or actuate controls while recording. It also permits the use of things like a separate hand-held shotgun mic, a mic with a "dead kitten" wind filter, or a wireless mic system for truly professional audio recording. Panasonic themselves sell an external stereo mic (the DMW-MS1) that plugs into the GH2's jack and mounts on the hot-shoe, but there are loads of third-party mic systems that should work just fine with the Lumix GH2 as well. (One important note, though: The audio-in jack on the Panasonic GH2 takes a 2.5mm plug, so you'll need an adapter to use mics with standard 3.5mm plugs on them.)

As mentioned previously, Panasonic doesn't publish specs for the GH2's audio recording capability, so we can't be certain of the sampling rate or number of bits of A/D resolution employed. That said, though, the audio tracks in AVCHD files show up as Dolby AC3 at 48 Ksps (Kilosamples per second) with a bit rate of 192 Kbps, and Motion JPEG files show up as 16 bits PCM at 16 Ksps sampling. Those sound like reasonable numbers, although the 16 ksps would set an upper frequency limit of 8 KHz for Motion JPEG, which seems a little low.

Audio recorded with the camera's internal mic seemed quite clear, but we do no tests to measure frequency response or sensitivity. We didn't have an opportunity to test with an external mic, so can't comment on the audio fidelity when recording from external devices. (We didn't have a 3.5/2.5mm adapter while we had the eval sample of the GH2, so couldn't test it with our external Rode SVM mic or our AudioTechnica wireless rig.) We did notice that there was a slight 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.

Given that we didn't test with an external mic, it's hard to say whether the audible hiss would be a factor in sound recorded from external sources, or if it's just a factor when working with the internal mic. We're inclined to suspect the latter, given that audio digitization isn't that challenging technically.

A welcome addition on the Panasonic GH2 is manual control of the audio level. An option on the third screen of the Video Record menu lets you choose one of four levels of mic sensitivity. It's not clear to us whether the level setting is absolute, or if it just acts as a bias on an auto-level adjustment. Our guess is that it's an absolute adjustment, as we didn't see much evidence of the camera adjusting gain levels automatically. Whatever the case, we felt that the manual level adjustment worked well in allowing us to set the audio recording sensitivity.

Panasonic GH2 Movie Recording User Interface

The Panasonic GH2 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 camera's top panel, and the camera will start recording video. Video resolution and file format are available via the rear-panel LCD, whether in any of the still-capture modes or the dedicated Motion Picture mode, and you can change these settings at any time via the Quick 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 GH2 to record little "video snapshots," rather than it being a big production to switch in and out of video mode. At the same time, though, the dedicated Motion Picture mode gives you a much greater range of control over the video recording than you'll find in most other cameras anywhere near the GH2's price point.

We've generally favored use of the shutter button to start and end video recording, but found ourselves really liking the convenience of the GH2's dedicated record button. Having it on the top panel, right behind the shutter button also made it very quick to access with our index finger, so it was simply a matter of reaching back slightly to capture video vs a 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 directly from a still-capture mode is that the aspect ratio can change 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. (The latter was our preferred approach.)

A minor niggle we had with with the Panasonic GH2's movie mode was that the Movie button required a rather deliberate press to either stop or start movie recording: Until we got used to it, we several times found the camera still recording video after we thought we'd stopped it. It wasn't a big deal, but we did feel we had to be very deliberate about pressing the Movie button to start/stop recording.

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/CSC cameras we've tested in this regard. Somewhat more disconcerting, though, was that the GH2 stopped recording early, with the end of the recorded video coming roughly 0.8 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. We've seen this on a number of other Panasonic G-series models now, and it can be quite problem until you know to allow for it. Once you're used to it, it's not a big deal to simply delay pressing the stop/start button until a good second or so after the action has ended, but you may end up chopping a lot of clips too short until you develop this habit. The good news is that the delay for beginning a recording is quite a bit shorter, at under a half a second.

Panasonic GH2: 2MP Stills During Video
One of the Panasonic GH2's more unusual features is its ability to capture up to 20 still images while a video is recording. Above is a reduced-size image of one such shot, captured during AVCHD video recording.
Here's a 1:1 crop from the shot shown above. These shots are only 2 megapixels (1,920 x 1,080), but they're more than good enough for 4x6 inch prints.

One unusual feature that the Panasonic GH2 carried over from some earlier models is its ability to capture up to 30 still images while a video recording is being recorded, simply by pressing the shutter button whenever you want to grab a frame. 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. These in-movie still images are limited to 2-megapixel resolution, and the feature is only available when a movie recording is initiated from a still-image capture mode. (When you're in the dedicated Movie Recording mode, pressing the shutter button toggles the video recording. That is, it starts it if a movie isn't currently recording, or stops it if one is.) Simultaneous still/movie recording is also not available when the resolution is set to WVGA, VGA, or QVGA in Motion JPEG mode.

While the resolution of these in-movie still images is limited to 2 megapixels, what's nice is that grabbing them doesn't pause or otherwise disturb the video recording in any way: The GH2's shutter button is also quiet enough that you can avoid creating clicks on the audio track if you're careful. (We noted this as a problem in Panasonic's GF2 model; it's nice to see it addressed now in the GH2.) 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. We found it very interesting to note that the resolution of these still images is actually 1,920 x 1,080 pixels, even when shooting in 1,280 x 720 video mode; This feature is available when shooting in any HD-resolution recording mode, whether saving in AVCHD or Motion JPEG format.

If you want higher-resolution still images during movie recording, the Lumix GH2 has an option to accommodate that as well, but at the cost of pausing video recording while the higher-resolution still image is captured and saved. In this mode, the resolution and file format of the still image is whatever you have selected in still-capture mode. The pause in the recording is quite brief, about a half a second, regardless of the still-image resolution chosen, or JPEG vs RAW file format. There's no impact on the video or audio tracks other than the half-second pause; there's no audible click or other artifact from the still image being snapped. Even though the still-image resolution in this mode can be set independently of the video, the feature is only available when the camera is recording video at HD resolution. Up to 8 still images can be captured during movie recording in this mode.

Setting adjustments in movie mode are made via the Motion Picture Menu, which for convenience shares a few items with the main Record Menu. Here's a list of the options found on the Motion Picture Menu:

Motion Picture Menu Options:
Top-Level Selection	Second-Level	Notes
Film Mode	- Standard - Dynamic - Smooth - Nature - Nostalgic - Vibrant - Standard B/W - Dynamic B/W - Smooth B/W - My Film 1 - My Film 2 - Multi Film - Cinema	These modes change color and tonal characteristics. Each mode permits manual tweaks of contrast, sharpness, saturation, and noise reduction. (NB: Shared with still-image REC mode; changing here changes on REC mode screen also, and vice versa.)
Rec Mode	- AVCHD (1080i) - AVCHD (720p) - Motion JPEG
Rec Quality	(AVCHD 1080) - FSH - FH (AVCHD 720) - SH - H (Cinema mode) - 24H - 24L (Motion JPEG mode) - HD - WVGA - VGA - QVGA	Two separate sets of options, depending on which AVCHD or Motion JPEG recording format is selected. 24P Cinema mode is selected via the Movie Mode menu; the topmost tab of the menu system in dedicated Movie Recording mode. (Note that WVGA isn't available in Intelligent Auto Mode.)
Exposure Mode	- P - A - S - M
Picture Mode	- (Movie priority) - (Still priority)	In Movie Priority mode, you can snap up to 30 2-megapixel still images during movie recording, without pausing the recording. In Still Priority mode you can capture up to 8 images at any resolution you like, but the recording pauses 0.8 second for each. Both options are only available when you begin movie recording from a still-capture mode.
Continuous AF	- Off - On	Controls AF during movie recording, independently of the AF-mode switch on the camera's top panel.
Metering Mode	- Multiple Area - Center Weighted - Spot	Spot metering follows face of subject when Face Detect AF is selected, follows chosen AF point in Spot AF mode (Also shared with REC mode)
iDynamic	- Off - Low - Standard - High	Adjusts contrast and brightness to improve apparent dynamic range (range of light to dark values that can be recorded). (Also shared with REC mode screen.)
Wind Cut	- Off - Low - Standard - High	Processes audio being recorded to attempt to remove wind noise.
Mic Level Disp.	- Off - On	Enables an audio level display in both the LCD and EVF displays. The level display is present during both still and video recording. The overlay's presence is also controlled by the Display button; it only appears in the display mode showing maximum overlay information.
Mic Level Adj.	(select 1 of 4 available levels)
Ex. Tele Conv.	- Off - On	Increases zoom by using only central pixels of sensor. Increases zoom 2x at lower resolution settings with still images, 2.6x when recording video at 1080 resolution, 3.9x at 720 resolution, or 4.8x when recording at VGA or lower video resolution. (Also shared with REC mode screen, but magnification factors are different for still images.)
Digital Zoom	- Off - 2x - 4x	Interpolates images to add constant 2x or 4x magnification, but with equivalent loss of image quality. Can be applied in combination with Ex. Opt. Zoom above. (Also shared with REC mode screen.)
Rec Highlight	- Off - On	Blinks any overexposed areas in the LCD and EVF to warn of the overexposure. The blinking does not appear in the recorded video.

Panasonic GH2 Video Quality and Artifacts

We felt that the Panasonic GH2's video quality was pretty comparable to that of its competitors, neither exceptionally better nor worse than that of other models. As usual, the AVCHD recording format provided a high-quality viewing experience (at least when viewed on a good-quality HDTV) with very small file sizes, but tended to lose detail when the camera was panned rapidly, or when there was a lot of rapid subject movement. Thanks to its higher 24 Mbps recording rate, there was less of this sort of degradation in the GH2's files than we've seen in previous AVCHD output that was limited to 17 Mbps. Also, as we've pointed out before, times of rapid camera or subject movement are exactly when our eyes will be less aware of fine detail, to its loss isn't as significant an issue as some of the freeze-frame crops below might suggest. Motion JPEG does much better with high levels of subject motion, but at the cost of files nearly twice as large. Overall, we felt the Panasonic GH2 produced very good-quality video. (However, while few people are likely to purchase a GH2 expressly for recording VGA-resolution videos, it does deserve noting that its VGA video is less appealing, with noticeable compression artifacts. Stick with its HD-resolution video and you'll be happier.)

Here are some examples of what we found in the Panasonic GH2's movie files:

Panasonic GH2 Video Quality Samples
AVCHD - FSH mode	AVCHD - 24H mode
With any camera, recording in 1080i mode can result in interlace artifacts (such as "combing" shown above) when the camera or subject is moving rapidly and the video is played back without proper deinterlacing. Good HDTV sets can significantly reduce the impact of this through their image processing, but it's best if you either record in a "P" (progressive) mode, or avoid rapid camera movement.	Even though its frame rate is lower, the GH2's 24p high-quality mode produces much clearer images in the face of rapid subject or camera movement. This shot was taken with a roughly similar amount of camera movement as the one at left, but in 24p vs the interlaced FSH mode.
AVCHD - SH (720p HQ) mode	Motion JPEG - HD (720p) setting
While progressive recording modes eliminate interlace artifacts, the AVCHD compression still exacts a price when faced with rapid movement. This shot shows loss of detail in the foliage when the camera was moving rapidly. (Although as noted above, this is far more rapid camera movement than you'd likely ever want to subject your audience to.)	This shot was captured with roughly similar camera movement to that on the left, but with the camera recording in Motion JPEG format. The detail is much better preserved, but at the cost of much larger file sizes.
AVCHD, SH (720p HQ) mode	Motion JPEG - VGA setting
As noted above, the GH2's higher available bitrate for AVCHD encoding gives much better results with moving subjects than earlier G-series models that were limited to 17 Mbps: This shot has plenty of detail, in a scene where the GH1's video would have been very muddy.	Motion JPEG doesn't automatically mean no artifacts, though: The Panasonic GH2's VGA-resolution video (640x480) has pretty severe compression artifacts, whether the subject is moving or not. If you only want low-res videos for web use, you'd probably do better with a digicam.
Motion JPEG - 720p setting	AVCHD, SH (720p HQ) mode
Sometimes, a little less detail is a good thing: The Panasonic GH2's after-dark videos were a little noisy, when recorded in Motion JPEG. Some minor banding can also be seen in the night sky.	The same shot, recorded just a few minutes later in AVCHD mode, shows a much cleaner image. Apparently the AVCHD compression clears out a lot of the image noise, while doing a good job of leaving edge detail behind. AVCHD clearly has the advantage here, for after-dark recording.

Rolling Shutter Artifacts

Panasonic GH2: Rolling Shutter Artifacts
While present, we found the Panasonic GH2's rolling shutter artifacts in most recording modes to be less obtrusive than those of many competitors. The slanted verticals in the shot above show this effect, and this was close to as bad as it got in any of the 720p modes, even with very rapid camera movement.
The one situation where rolling shutter artifacts became more evident was in the 24 frames/second recording modes. These are progressive-scan 1,080-resolution modes at 24 fps. The higher-resolution progressive readout seemed to make the 24H and 24L modes much more prone to rolling shutter than any of the 720p modes were.
AVCHD	Motion JPEG
24H 1,920 x 1,080p, 24 fps, 24 Mbps View on Vimeo | Download Original (11 seconds, 18.1 MB)	HD resolution 1,280 x 720p, 30 fps View on Vimeo | Download Original (11 seconds, 19.1 MB)
24L 1,920 x 1,080p, 24 fps, 17 Mbps View on Vimeo | Download Original (11 seconds, 12.2 MB)	WVGA resolution 848 x 480p, 30 fps View on Vimeo | Download Original (11 seconds, 6.8 MB)
FSH 1,920 x 1,080i, 60 fields/s, 17 Mbps View on Vimeo | Download Original (11 seconds, 7.6 MB)	VGA resolution 640 x 480p, 30 fps View on Vimeo | Download Original (11 seconds, 6.4 MB)
FH 1,920 x 1,080i, 60 fields/s, 13 Mbps View on Vimeo | Download Original (12 seconds, 6.5 MB)	QVGA resolution 320 x 240p, 30 fps View on Vimeo | Download Original (11 seconds, 3.2 MB)
SH 1,280 x 720p, 60 fps, 17 Mbps View on Vimeo | Download Original (11 seconds, 5.8 MB)
H 1,280 x 720p, 60 fps, 13 Mbps View on Vimeo | Download Original (11 seconds, 5.6 MB)

Essentially every video capable digital SLR/CSC currently on the market exhibits motion-related distortions called rolling-shutter artifacts. (Also popularly known as the "jello effect," for the wobbly appearance of videos affected by it.) These are caused because the image data is captured and then read off the chip sequentially by rows, rather being captured all at once.

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.

The specs for the Panasonic GH2 indicate that it reads a frame of data from its sensor either every 1/60 second (for AVCHD NTSC mode) or 1/50 second (in AVCHD PAL mode). These are fast rates for cameras in this category, and likely why we found the GH2's rolling shutter artifacts much less obvious in most recording modes than they are in some competing models. Even when the camera is only recording data at 30 fps, the fact that the camera can read out the entire sensor's worth of data in 1/60 second means that the rolling shutter artifacts will be only half as prominent as in cameras that take the full 1/30 second to read out the image data. Whatever the case, this isn't a scientific test we're performing here, but it supports our general sense that the Lumix GH2 did much better in this respect than many models we've worked with.

The one exception to the GH2's excellent rolling shutter performance was in its 24P Cinema recording modes. These modes record at 1,920 x 1,080 resolution at 24 frames/second with progressive scanning. The high-resolution progressive scanning apparently slowed the sensor readout a fair bit, so rolling shutter became more of an issue. While quite a bit worse than the 720p recording modes, the 24p rolling shutter artifacts are about on par with what we've seen from a number of other camera systems.

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 GH2 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 much harder for computers to decode. If most of your video playback will be on a computer, you may find Motion JPEG to be more to your liking. On the other hand, if your computer supports AVCHD fine, that would be the preferred format, given its space efficiency.

As of this writing (in mid-May), support for AVCHD on the Mac platform is still pretty poor. The free VLC player program does a decent job, but is somewhat prone to motion artifacts. We're not aware of any other free player software for the Mac that does any better. Panasonic provides software for viewing and working with AVCHD video for the Windows platform, but not for Macs. More recent versions of Windows Media Player support AVCHD files as well.

Panasonic GH2 Video Mode: The Bottom Line

Overall, the Panasonic Lumix DMC-GH2 is a great camera for consumers or enthusiasts looking for a capable interchangeable-lens camera that can record video without the hassles of the largely-manual focus found on many other models. While not perfect, its live autofocus tracking during video recording is significantly better than that of most SLRs and several competing CSC (mirrorless interchangeable lens) models we've tested. (Really, only Sony's SLT translucent-mirror models equal it.) The 14-140mm kit lens was designed specifically for video recording, and it does an excellent job, offering fast focus, a continuously-variable aperture and virtually silent operation. The Panasonic GH2 also offers full manual control of aperture, shutter speed and ISO setting, a key feature for video enthusiasts seeking full creative control. Video quality is very good, and both 1080i and 720p recording is offered, as well as 24 fps 1,080p, at a bit rate of 24 Mbps; higher than on any other AVCHD-capable still camera we're aware of. The icing on the cake is stereo recording with manual level control, via either the built-in stereo microphone or an external mic connected via a 2.5mm plug. Combine this rich feature set with the GH2's compact size (particularly including the 10x 14-140mm zoom lens), and you have a phenomenal platform for HD video recording. (And it's no slouch as a still camera, either.)

All in all, we had a very good experience with the Panasonic GH2's video, and its smooth-working autofocus is just what the average consumer needs for hassle-free video recording.

Panasonic GH2 Video: Cool Videos

While our test shots reveal a lot about the Panasonic GH2's performance, they're hardly representative of what a talented videographer can do with the camera. There's plenty of examples of artistic work created with the GH2 over on Vimeo, here's a brief sampling of a few clips showing a range of different styles and subject matter. (Go to Vimeo and search on "Panasonic GH2" to see many more):

Panasonic GH2: Creative videos
Melting Point: Soma Spring Fashion 2011, by Mike Kobal Here's a very high-style fashion shoot video, produced by Vimeo Plus member Mike Kobal. View on Vimeo
Panasonic GH2 Skate, by Atiba Jefferson and Ty Evans This was shot by the two artists for Panasonic's 2011 CES show, using a variety of Lumix G-series lenses. The piece was shot using the GH2's "Nostalgic" film mode, with no color grading, to show the image straight from the camera. View on Vimeo
"Panasonic GH2", by Gary Some grading on this one, in Adobe Premier 5, but beautiful skin tones; a very beautiful, soft yet vibrant look to the video. View on Vimeo
Panasonic GH2 - Exploring Africa, by AVL Films Professionally produced by AVL Films and Framework Studio in Los Angeles, shown by Panasonic during the week of CES 2011. A beautiful short feature that really shows what's possible with a GH2 and Panasonic's lenses in the hands of skilled pros. View on Vimeo