What About 8K video?
/Hey folks. A question has come up about the importance of 8K video. To say that many people are asking would be an enormous lie. In reality, the only people asking are Canon shooters because Canon is making such a big deal of 8K video. My R5 has the capability to shoot 8K video, so I should be excited right?
Not One Tiny Bit
First off, and let’s agree to be honest about this, the only people who care about 8K video are filmmakers with enormous budgets AND access to cinemas capable of showing 8K video. That is, a VERY SMALL number.
Moreover, most users are still using displays that are only 2K, so there is no ability to even see 8K video to edit it. While many televisions are 4K capable, 8K capable televisions are few and far between and outrageously expensive. Films are not being shot in 8K and what you can purchase is at best 4K and MASSIVELY compressed so it streams ok. No single DVD can hold a full load 4K movie, so forget about 8K. 8K is a solution desperately in search of a problem that no one actually has.
Why The Fuss?
Actually only Canon is making any kind of fuss. Panasonic, who do superb high end video products has decided not to bother putting 8K in their interchangeable lens cameras. They have many good reasons. The first is sensor resolution. 8K is the delivery of an image 7680 x 4320 pixels so each frame is about 33.2 megapixels. Micro four thirds sensors are not that pixel dense and that level of density on that size of a physical sensor would make for pixels with extra tiny surface areas which would result in plenty of visible noise without the aggressive application of computational video and massive compression at the time of capture. So why bother.
But What About Quality?
If you cannot play it back, the core quality is irrelevant. If the video gets massively compressed to fit on storage and through the incredibly narrow bandwidth in cameras, there is no quality to be gained. It’s a big number, like 100 megapixels, that in practical use means absolutely nothing, except to those who want to brag about specs (HINT : No one is impressed) or has serious insecurity issues.
Tell Me About Bandwidth
Let’s presume that the effect of compression of each frame at high quality is not dissimilar to JPEG fine. That means that, presuming no additional crud is added per frame, that each frame instead of being 33 megabytes without any processing gets compressed to about 10 megabytes. That means at the common video frame rate of 30 frames per second, your camera would need internal bandwidth of 285 Mb/s without considering any transmission overhead. Guess what? That will require a completely different buss inside the camera, a different card IO engine and cards capable of writing at at least twice that rate because of how streams hit the storage controller. No maker actually publishes their internal bandwidth outside of cinematic video cameras, and only CF Express B could keep up for a short period and SSD storage for any length of clip. It’s just the reality of physics.
Storage
Consider then 285 Mb/s as the minimum data transfer, so that means that a general 10 second clip is going to need nearly 3GB of storage before overhead. Consider that a two hour movie typically means days and weeks of footage for editing, you had better have serious stock in Samsung or another premier SSD maker. Extrapolation of publicly validated data for 4K video says you will get 4 hrs 33m on 1TB. Divide by 4 for 8K so you will need 1TB of storage for every hour and 8 minutes of 8K video. Storage is getting less expensive but not that inexpensive and there is presently no way to put an SSD in your camera unless it is a professional cinema camera.
Editing
Video needs to be edited. I know that there is all kinds of unedited sewage on the Internet, but for video to be memorable, it requires decent editing, decent audio, colour grading and a high quality render. Unless you own a pool of high end machines that do nothing but rendering, rendering an 8K final video for playback on your home computer is time measured in days and weeks. Given the typical human attention span these days, there is no point at all.
The Real Gating Factor
While every camera available in the market that is current does video and most of them do very decent looking 4K video, the data tells us that over 90% of buyers of these 4K capable cameras have NEVER shot a single clip of video. So why do the makers spend so much time on video? Because it sells more gear and if users picked up on video, it would sell even more gear. Their business is to sell you the latest and greatest not to help you get the most out of what you already own, and perhaps may not even use to its maximum potential for stills. I love that camera makers make a big deal of burst modes of 20fps but then you read the fine print and discover that’s not quite true with any consistency for 14 bit RAW files, yet every camera in the last three years has been able to shoot 4K video at 30fps, a still from which is an 8MP JPEG with more resolution than most all displays and televisions can render. It’s all toro poopoo. The only person needing more resolution is the person whose post cropping images would be smaller than 8MP. Since such a small percentage of photographers print, which does have greater resolution potential, the idea of high res for social media or the web or your phone is a big sack of BS.
Conclusions
If you are not shooting video now, worrying about 8K video is a waste of your time. If you are shooting 4K video now, your ability to see it is already maximized in televisions and displays that normal humans can afford and for which there is content. If video matters to you, then learn to use what you have and use it. If video does not matter to you, like the other 90%, learn to ignore every maker and salesperson bafflegab about video because it is completely irrelevant to you.
Please feel free to leave a comment or post a question. If you shop at B&H Photo Video, please use the link on the site which costs you nothing and pays me a tiny commission. Thanks for reading and until next time peace.
