I don’t have a GH4 that I can play with hands on. But that won’t stop me from explaining some of the best features of this awesome little camera! Obviously it can shoot 4k. It can also export 10bit 4:2:2 via HD monitoring. Lets take a closer look at the Panasonic GH4.
Panasonic GH4 Bitrate
To have equivalently compressed video, 4K resolution should have about 2x the bitrate of standard HD video. This is a loose rule and the logic behind it is that compression artifacts are smaller because the pixels on the display are smaller. Point of the matter is; the 4K video of the GH4 will have a bitrate of 100Mbps and the 1080p video will have an extraordinary bitrate of 200Mbps. The 4K video has a lower bitrate because 4K 200Mbps video requires more hardware resources. Like I said, it’s not a big deal.
- The GH4 can shoot at 100Mbps (4K) or 200Mbps (1080p)
- The GH3 can shoot at 73Mbps
- The Canon 5D mkIII has a variable bitrate, averaging 91Mbps
- The Canon 5D mkII maxes out at 38Mbps
The moral of the story is that the GH4 has a very high bitrate, and you will see fewer compression artifacts. Even though the bitrate of the 4K video is only 2x bigger than the bitrate of 1080p (4K video is about 4x the resolution) the compression should look about the same. And guess what? If you downscale that 4K video to 1080p, the compression artifacts will be greatly reduced!
The GH4 Crop Factor
The crop factor is 2x when shooting 1080p. The Gh4 has a 2.3x crop when shooting 4K. The reason the crop is greater in 4K is a choice made by Panasonic to get better image quality. Because most cameras have sensors that are designed for photography, they have too many pixels for video. You can either fill the whole sensor (so the crop factor does not increase) and skip lines (recording all the pixels would give you some crazy shit like 8K video or something!), or you just record a smaller portion of the sensor with less line skipping (less aliasing!). The moral of the story is that if you interpolated the 4K footage to maintain a 2x crop factor, the video quality would be slightly worse.
Buying a Metabones Speed Booster is popular now a days. It is a way for micro four thirds shooters to increase their aperture and decrease their focal range. With the Metabones .71x Speed Booster, your effective crop would become 1.42x when shooting 1080p, and 1.633x when shooting 4K.
Panasonic GH4 Dynamic Range
The GH3 had better dynamic range than the Canon 5D mkII. Do I expect the GH4 to have better dynamic range than the GH3? Yes. I predict the GH4 will have excellent dynamic range. Not as great as the Black Magic cameras, but excellent by non RAW standards. Because the GH4 can output 10bit 4:2:2 video, the dynamic range of the 4:2:2 10bit output will be even better and should rival the Black Magic cameras.
Panasonic GH4 Rolling Shutter
Estimated 50% reduction in rolling shutter: The GH3 had excellent rolling shutter reduction making the GH4 possibly the camera with the least rolling shutter under $3,000. The Digital Bolex D16, priced at $3299, and the Blackmagic Production Camera 4K, priced at $2,995, have global shutters meaning they do not suffer from the jello effect caused by rolling shutter. Rolling shutter can be fixed in post production, but having clean footage in camera is always preferable to fixing everything in post.
Panasonic GH4 Gamma Curves
The Panasonic GH4 features Cinelike D and Cinelike V gamma curves. Cinelike D allow you to make the most of your dynamic range by preserving details in the shadows and highlights, it gives a very flat look. Cinelike V is more contrasty and gives you a good all around gamma curve for every day shooting. Basically, you can adjust the gamma curves inside the camera so that you can shoot with whatever “look” you want.
Panasonic GH4 Audio Features
The camera comes with your standard built in microphone. I assume the microphone sucks. You have a microphone jack and a headphone jack. So you can use an external microphone and use headphones to monitor audio. The best solution is to buy and external recorder, an external microphone and forget about the GH4 audio features.
To get the most out of this camera, I suggest you at least buy an interface that can capture 10bit 4:2:2 video. The most popular devices for capturing uncompressed video are monitors made by Atomos.
- Atomos Ninja: Low resolution 4.3 inch 480 x 272 touchscreen monitor. It only has HDMI input (no output). It does not feature useufl monitoring features such as focus assist, zebra & false color monitoring. Records 10-bit, 4:2:2 in ProRes format to HDD/SSD. $280
- Atomos Ninja 2: A fairly low resolution 4.3 inch 800 x 480 touchscreen monitor with focus assist, zebra & false color monitoring. Records 10-bit, 4:2:2 ProRes or DNxHD to HDD/SSD. $700
- Atomos Ninja Blade: 5 inch IPS 1280 x 720 touchscreen monitor with focus assist, zebra & false color monitoring. Features waveform vectorscope display and records 10-bit, 4:2:2 ProRes or DNxHD to HDD/SSD. $1,000
- Atomos Smurai Blade: 5 inch IPS 1280 x 720 touchscreen monitor with focus assist, zebra & false color monitoring. Features waveform vectorscope display and records 10-bit, 4:2:2 ProRes or DNxHD to HDD/SSD. Has HD-SDI input and output, and 12 channel audio. $1,300
- Atomos Ronin: 5 inch 800 x 480 touchscreen monitor (pretty mediocre if you ask me), XLR audio recording, focus assist, zebra & false color monitoring. Features Timecode and records 10-bit, 4:2:2 ProRes or DNxHD to HDD/SSD. Has HD-SDI input and output, and 12 channel audio.$1,300.
If you don’t want an Atomos for some reason, you can settle for the Panasonic LUMIX YAGH Interface Unit (DMW-YAGH). It allows you to synchronize the time codes of multiple cameras for simultaneous recording. You can record uncompressed video without this giant brick. Just buy an Atomos Ninja 2 instead. I would only get the YAGH interface if I needed timecode. Keep in mind that the YAGH mounts like a battery grip; it has no monitoring capabilities (no screen). I don’t know how much the YAGH will cost, but the thing look like it will cost $600+. For that money you would be better off with an Atomos Ninja 2.