Today we’ve got a great green screen and chroma key comparison produced by Video Alchemy between the Panasonic GH4 with a standard compressed 4K output and the Blackmagic Cinema Camera with a 2.5K uncompressed output.
Usually, when working with chroma key or green screen one would use a very high quality output like cinemaDNG RAW or ProRes 4:2:2 /4444. However, the question here is – can a 4K camera like the Panasonic GH4 with a compressed output (in a 4:2:0 colour space) work as well?
Which one will be the best for green screen work? The results may surprise you. Let’s see the video below:
Jump to the different sections of the video in order to see the information you need.
- After Effects Section 1:41
- Results Comparison 9:06
- Conclusion 14:12
Paul Shillito from Video Alchemy used the following lens setup for both cameras:
Panasonic GH4 with 12-35mm f2.8 Lumix lens
BMCC EF with Tokina 11-16mm f2.8 lens
As far as we can see below, the 4K standard H.264 output from the GH4 is great for chroma keying or green screen work. The lowest output in theory actually performs better compared to the output options BMCC provides.
The compressed high-resolution output of GH4 beats the uncompressed lower resolution of the Blackmagic camera and with the added benefit of a much smaller file sizes will have a bigger impact on CPU’s and GPU’s performance and in terms of disk space and storage. The only considerable advantage of shooting Blackmagic RAW is if you plan to do a lot of color grading or some sort of heavy VFX work.
The Panasonic GH4 has a lot more usability options – you can get 1080p ProRes 10-bit 4:2:2 files via the HDMI output with an external recorder (like the Atomos Ninja 2), but as we’ve seen the standard 4K compressed footage directly from the camera, will do a very good job in most situations.
BMCC owners have no reason to be unsatisfied as well. The Cinema camera and the Pocket camera perform considerably well and the ProRes 422 HQ files they produce also are superb for green screen work and chroma keying. They are a way better than the poor 8-bit 4:2:0 video codec implemented in the first generation of DSLRs for instance.
In the future, we’d be eager to see a side-by-side comparison between the BMPC 4K and the GH4 in terms of resolution where the difference should be negligible, in theory at least.