Panasonic GH4 Field Test Part II

Panasonic GH4 Field Test Part II

Video Recording and that's a wrap!

By William Brawley | Posted: 08/04/2014

Whether you're a still photographer who's just dipping his or her toes into the ocean that is video production or you're a hardcore, seasoned professional videographer, the Panasonic GH4 is like the "Swiss Army knife" of video -- boatloads of file formats, bitrates, framerates, clean HDMI output, headphone jack, full-time AF... you name it, the GH4 probably has it.

The GH3 garnered heavy praise from us for its impressive video quality and pro-level feature set -- and doing so at a very "un-pro-like" price point -- and the new GH4 has upped the ante with not only 4K video recording, but also with even higher quality 1080p video bitrates (with a total of 26 different video resolution/frame rates options), cinema-like picture styles and advanced production features like zebra pattern, focus peaking and clean HDMI output at 4:2:2 8- or 10-bit quality.

And still, the GH4 maintains a relatively low price for a pro-level camera at around $1,700, which is impressive considering it's: A) Panasonic's flagship photo-oriented interchangeable lens camera (the AF100 being a professional Micro Four Thirds camcorder) and B) a camera with video features and image quality that meet or surpass professional cinema cameras that can cost upwards of tens of thousands of dollars.

While I certainly don't consider myself a professional videographer, I've had a fair share of experience in video production, and after spending some quality time with Panasonic's new top-of-the-line Micro Four Thirds camera, I'm ready to discuss my thoughts on the video recording features of the GH4.

Image Quality

First of all, the video quality on the Panasonic GH4 is nothing short of impressive. Having come from using Canon HD-DSLRs for my video recording needs -- the Canon 5D Mark II and 7D -- I was stunned with the image quality the first time I used a GH3, especially at low ISOs -- the sharp, fine detail and flatter, wider dynamic range, and not to mention the ease of use with full-time autofocus. With the GH4, Panasonic has continued with that high level of image quality, and now with 4K resolution, the camera is even more stunning.

I shot all video with the Panasonic 12-35mm f/2.8 lens, and video at both 4K and 1080p resolutions is very sharp and highly detailed with excellent dynamic range -- especially with shadow detail -- even with the "Standard" Photo Style setting. Color rendition looks realistic and pleasant without being overly saturated. 4K resolution footage uses the IPB compression scheme at 100Mbps, while at Full HD, you have the option for some seriously high bitrate video with 200Mbps and ALL-INTRA compression that produces extremely high quality video. (There are also 100Mbps and 50Mbps HD video quality settings for MOV and MP4 formats.)

With a Four Thirds sensor, you're not going to get the high ISO performance as you would with an APS-C or full-frame camera, such as the Canon 5D Mark III or Sony A7S. Still, high-ISO video quality from the GH4 is not to be scoffed at, at least not in properly exposed scenes. We shot a series of Still Life images in our test lab using the GH4's 4K resolution, and noise was very well-controlled all the way up until ISO 3200. At ISO 6400, you can see a noticeable jump in noise. However, in poorly-lit scenes such as in the night time video below, or the low-light torture test using a candle-lit scene, the GH4 looks a little rough at ISO 3200-6400 with lots of noise, though fine detail is still rather impressive.

Shooting often with Aperture Priority mode, I did notice a tendency for the GH4 to clip highlights when shooting in very harsh, sunny conditions, while maintaining good exposure in the mid-tones and the shadows. However, there are various image adjustments to counteract or compensate for high contrast scenes or for avoiding blown highlights.

First, you can always adjust exposure compensation, though you have to be careful not to end up with an overall underexposed image or crushed blacks in the shadows. The GH4 also lets you adjust the shadow and highlight tone curves separately (a max/min of +/- 5 increments), to help rein in highlight tones a bit and boost the shadows. In a high contrast test scene I shot, I had to adjust exposure compensation down to -2EV to avoid blowing highlights, however I was able to adjust the shadow tone curve to bring out a little more detail in the darker tones. A word of caution though: I was outdoors in bright lighting at a low ISO, but boosting the shadows with the tone curve adjustment could introduce some shadow noise at higher ISOs, so adjust accordingly.

In a quick test for rolling shutter, the performance at Full HD resolutions was very good. I saw practically no rolling shutter at 60p and only a hint of the "jello-effect" at 30p and 24p. However, at 4K resolutions -- both 30p and 24p framerates -- the rolling shutter effect is more noticeable, though still not to a degree that I would consider severe. It's becoming easier to correct for rolling shutter with various non-linear editing programs, but as long you're careful when panning horizontally, especially at 4K, you should be just fine.

Similarly, moiré and aliasing was minor, although it can still make an appearance on notorious surfaces like fine meshes or certain fabrics. I actually noticed it less on 4K video and more so at 1080p and 720p resolutions.

Special Features

Fans of slow-motion video will be very happy with the upgrade to the GH4. While the GH3 also had a Variable Frame Rate setting, it only went up to 60fps and only offered playback set to 1080/24p. The GH4, however, lets you boost the frame rate up to 96fps at Full HD with playback set to 30p or 24p, depending on the video format you choose. The VFR adjustment is only available in "MP4 (LPCM)" format at 1080/30p and 1080/24p at the 100Mbps bitrate (otherwise the VFR option is disabled).

The VFR setting was very fun to use, and allowed me to capture some fun footage of Charlotte, IR's "ISO-standard Australian Shepherd," chasing the Frisbee. The GH4 makes the process very simple -- set the frame rate speed you want, point and shoot. The camera re-times the footage for you, so there's no need to calculate frame rates or lengths of clips and do the heavy lifting in a video-editing program. On the opposite end of the scale, you can also have a very slow frame rate -- down to 2fps or 1200% slower for 24p playback or 1500% slower for 30p -- for a timelapse-like effect or otherwise fast-motion video.

There is a caveat to this VFR mode -- no continuous AF. Regardless of whether or not you have it set to AF-S/AF-F or AF-C modes, enabling a variable frame rate speed kicks it to manual focus. When I was out shooting, I normally kept continuous AF turned on, but when I played with the VFR mode for some slo-mo video, I didn't realize at first that it was in manual focus. On the rear LCD, the image looked in focus, but it was only when I watched the videos on the computer at full-resolution that I noticed they were indeed out of focus for a portion of the video.

The Panasonic GH4 is also packed with various advanced and professional-level features, many of which are beyond my level of expertise and my ability to test due to lack of the necessary equipment, such as the advanced audio, timecode and SDI video output with the DMW-YAGH Interface Unit (which we did not have for reviewing).

Some of the new advanced features I was able to experiment with were the new "cinema-style" gamma settings and the image luminance settings, Master Pedestal Level and Luminance Level.

When shooting video that will later undergo some form of post-production, especially color grading, a lot of advanced videographers want to have as much latitude as possible to tweak and massage the image without degrading it. While the GH4 doesn't record RAW video, the idea is the same as it is with RAW still images -- the more information you maintain, the more you can adjust later (i.e. bring detail out from the darker areas, rein in the highlights, or more easily correct colors). As such, many advanced users opt for a flatter, lower-contrast image profile with as much dynamic range as possible for recording video, making it easier to tweak the final image in post-production.

The Panasonic GH4 has a wide variety of ways to alter the look of video footage apart from the standard Picture Style presets, each of which include user adjustable levels of contrast, saturation, sharpness, etc. The GH4 introduces two new Picture Style presets -- Cinelike D and Cinelike V -- to give videographers a quick way to give a more cinematic look to their footage. I shot a few test videos comparing the two "Cinelike" styles versus the "Standard" picture style, which you can see below. The Standard Picture Style has fairly strong contrast with bright highlights, whereas the Cinelike D uses a gamma curve that is much lower in contrast -- shadows detail is more apparent and highlights are toned down and less apt to be blown out. Now, "Cinelike V" is more 'contrasty' -- even compared to Standard P.S., but still has more toned down highlights.

Now, you can go even further by customizing the Cinelike D style by dropping the contrast and sharpness settings for an even flatter, lower-contrast image, making the footage even more suitable for post-production massaging.

The GH4 brings even further image adjustments, which should be notable to seasoned professional videographers. Panasonic has now included a Master Pedestal adjustment to let shooters adjust brightness level of the image based on the black level. This not only helps adjust the image to have more or less contrast, but also allows for easier matching of footage from multiple cameras.

Panasonic has also introduced an adjustable luminance level for matching the source footage to its proper output format, such as those for broadcast video or viewing on a computer.  In a typical RGB color space, luminance level ranges from 0-255, with 0 being black and 255 being pure white. While the GH4 will let you shoot video at the 0-255 range, it actually defaults to 16-255, setting the black level at 16, which helps prevent very crushed blacks when played back either on a computer or in broadcast video. However, the "studio standard" luminance range for broadcast TV, HDTV, Blu-Ray, etc., all use a different range -- 16-235 -- which keeps the black levels from being too black and the highlights from being too high that they clip. The GH4 can be set to this luminance level as well for use in critical professional production or studio settings.

Focusing

Like the GH3, the new GH4 includes full-time autofocus during video recording, which has become a fairly mainstream feature these days with mirrorless cameras and some DSLRs. Coming from a Canon 5D2 and 7D with manual focusing only, I found having AF during video recording very nice for most scenarios, especially in run-and-gun situations. However, indoors and on areas of low-contrast, the GH4's AF can still hunt a bit -- even with Panasonic's new DFD technology with the 12-35mm lens -- which can be a bit disrupting to video recording with your image hunting and wobbling as it adjusts focus.

Like with the Canon 70D which does support AF during video recording, the touchscreen on the GH4 allows you to tap-to-focus before and during recording. While video is being captured, taping lightly to focus produces a very smooth, cinema-like focus transition between subjects. It's not a super fast transition, though, so trying to tap-to-focus on fast-moving subjects can be tricky.

For more fine-grained focus control, you can also manually focus and display peaking and an adjustable magnified view, which are very handy things to have that insure you have crisp, critical focus. Even in MF mode, there's a option on-screen to tap to quickly AF, which I found very helpful in quickly setting focusing, and then letting me fine-tune or confirm if I had critical focus.

Audio

The audio features on the GH4 are fairly standard fair nowadays compared to other enthusiast- and professional-level video-capable stills cameras. There's both a 3.5mm microphone input jack and headphone jack for monitoring audio. The mic input levels are adjustable, with a range of -12dB to +6dB, and there's a variable-strength wind noise filter setting.

One very handy audio feature I discovered is that you can adjust the mic volume level in-camera during recording. Using the touchscreen interface, there's a slide-out set of tabs along the right edge of the screen, and you can tap open the movie options and choose a mic level adjustment, all while video is being recorded. Obviously it goes without saying, but be sure to use a light touch as you could easily bump the camera and ruin a shot with a forceful tap.

As with most things related to the GH4, options abound in terms of audio recording formats. For most 4K resolutions and the high-bitrate Full HD containers, audio is recorded in uncompressed Linear PCM format. (4K resolution in the MP4 container uses AAC compressed audio.) With AVCHD, however, Dolby audio is used, and for other lower bitrate MP4 videos formats, AAC is used for audio.

Using the optional DMW-YAGH Interface Unit, you can have additional audio connections and controls. With the unit you'll get 2 mono XLR inputs for line-in or mic input with separate volume control for the left and right channels. There's also an audio level display and 48 volt phantom power for each channel to support condenser microphones.

It's a wrap: My summary of the Panasonic GH4

My experience shooting with the Panasonic GH4 has been overwhelmingly positive. It's a very solid camera -- build-wise and feature-wise. With design and handling more like a smaller DSLR than a super-portable mirrorless camera, the GH4 will feel right at home in the hands of seasoned DSLR shooters. The larger contoured grip is very comfortable and secure in the hand, and the plethora of external controls, including the two thumb and forefinger control dials make for a familiar shooting experience. I particularly loved the dedicated drive mode dial and conveniently-placed AF mode switch, which let me quickly change shooting parameters from, say, a portrait shot to being able to capture a fast-moving subject such as a birds or other wildlife (with a super quick 12fps burst speed with no AF -- impressive).

For still photography, the GH4 is still a very capable camera. It's not leaps-and-bounds better than the GH3, however, with a similar resolution sensor, image quality and high ISO performance. And speaking of high ISO performance, that's one area where the smaller Four Thirds sensor -- compared to similarly-priced APS-C and now even full-frame cameras -- shows its weakness. I was very comfortable shooting up to around ISO 1600, but beyond that, you start to notice either a) a lot of noise or b) lots of noise reduction processing, at least at default settings for JPEGs. I will say the GH4 is still a respectable camera with a good amount of fine detail up to around ISO 2500-3200. And the new DFD autofocus technology was for the most part super-quick and silent. On all but the trickiest, smallest and lowest of contrast subjects, the GH4 felt about as fast as a DSLR -- focus was nearly instantaneous.

The big story with the GH4, though, is video. 4K video. And it is awesome. It was my first foray into 4K video, and the GH4 proved a very capable camera. The GH3 had already proved itself an excellent performer with video, and the GH4 continues that achievement. Videos at both 4K and HD resolutions were very crisp, with excellent detail, colors and dynamic range.

For advanced videographers, the GH4 provides a plethora of image quality controls and tweaks to get your video exactly the way you want or need it to be, including image presets -- adding two new "Cinelike" gamma presets -- as well as dynamic range adjustments, black levels, sharpness, and highlight / shadow adjustments. If you're looking to integrate the Panasonic GH4 into a professional production or studio shooting environment, you're pretty much good to go  -- with clean HDMI output (with 4:2:2 8/10-bit quality), zebras and focusing peaking, color bars and timecode -- you name it.

All in all, the Panasonic GH4 is one heck of a camera that crams a ton of features and performance into a compact, well-priced package. Whether you're stepping up to a more advanced mirrorless camera, switching from a DSLR or off filming with a professional cinema or video production, the GH4 is capable, comfortable and relatively affordable (though if you're a professional videographer, the GH4 is a down-right bargain compared to the competition).