A Look at Video Capture Formats
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For most of us shooting video, we give very little thought to the video capture format that we use. Our cameras will typically offer MP4 as their standard, most also offer MOV.
Either is very good for video. Files are relatively small, and look very good when played back on up to 4K devices, presuming you are shooting at least at 1080 resolution. Depending on your frame rate, you can get a filmic or more video look.
So what are you actually getting in this situation? Think of each frame as if its a JPEG. Looks decent enough, but is highly compressed for space. For lots of things this is great but you are giving up some dynamic range, you may not be able to get better than 8 bit video. Also you are going to get the default colour profile that you set in the camera, if offered the option, or get a profile that you cannot change.
What is Log?
Many of our modern cameras that shoot video will offer something called a Log format. The big difference with Log is that there is no applied colour table. Different Log formats have different design specs, and mixing different Log types in the same video can sometimes be challenging to get the final colours across the board. When you view Log footage it looks very flat and with low contrast. In post production you will add a colour profile, often called a LUT specifically designed for a particular Log type.
For example, Sony do several different Log formats, each tuned for a specific response. In post processing you would apply the appropriate colourization for the Log format. In this case, if you have sequences shot in SLog2 and sequences in SLog3, when you apply the format specific colourization, it makes your final sequences look consistent when you edit your clips together. into your final video. The viewer does not know that each clip has its own colourization model.
Alternatively you could use a non-Log specific LUT, but remember that different Log formats with the same LUT applied will look different after the LUT was applied because they start in a different space.
Better editing tools, (I use DaVinci Resolve, but Premiere Pro and Final Cut Pro have decent colour tools) will allow the serious colourist to pull things together.. Log files are larger and need more bandwidth in the camera because they are not nearly as compressed as MP4 or MOV. Larger files also mean more time is required in the editor and when transcoding to the final file that will be used for playback, again typically an MP4 or MOV.
What About RAW?
Still photographers are very attuned to shooting in RAW because those files are mostly unprocessed so there is more latitude in post for working on the image. Video is the same but also different. Imagine your camera shooting 30 full res RAWs every second for a clip that is 10 seconds long. If the RAW still is 8mb (a 4K still), each second is 240mb and ten seconds is 2.4GB. This consumes storage very fast and because of the size, your camera needs internal bandwidth that is very very large. The average modern still camera is rated at just over 100mb/s. These cameras may support Log but will not support RAW effectively. Some makers use their own video RAW formats that need less bandwidth, but you are giving something up. This is why you will find that cameras that can do RAW video all depend on super fast CFast cards and similarly high internal bandwidth. Professional video cameras that are designed to shoot RAW video, often CinemaDNG or what Fujifilm and Sony do, are built very differently. These cameras are designed with heat sinks to keep the camera from overheating and also have comparatively massive power supplies. If shooting RAW video is your raison d’etre, you’re going to be looking at a different camera from your traditional mirrorless.
The other thing that RAW video needs is a very powerful computer. The files are enormous and editors are doing non-linear editing. You need very fast storage like SSDs, big CPUs and big GPUs. You also need LOTS of system memory or you are going to find that your editing process gets very slow. A 30 minute 4K video project is going to be at least 432GB so the system is going to need a lot of horsepower.to handle that.
This means that shooting video in RAW is a very specific thing and is still mostly used by commercial studios who share editing across multiple editing stations and who work in smaller pieces.
Summary
If you want to step up from generic MP4 and MOV formats and your camera supports it, consider learning to work with Log formats. You get richer content and you have a new skills development opportunity in learning about colourization for video.
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I'm Ross Chevalier, thanks for reading, watching and listening and until next time, peace.
