4K video and the camera’s that record it are now becoming available at reasonable prices, even if there is little in the way of devices or services to to actually play the footage back on to.
But for anyone using HD at the moment 4K offers the opportunity to capture much higher quality video footage and the advantages that it brings with things like the ability to do digital zooms in the edit of up to 300% (if the final output is 720p) and getting much cleaner images for VFX work.
However things aren’t always quite so rosy in the garden. The consumer range 4K video cameras will still have compressed outputs so while your getting a higher resolution you still have the nasty compression artifacts and you still loose 75% of the colour info with 4:2:0 chroma sub-sampling.
In this video I look at the sort of camera you need if you want to get all that lovely 4K’ness in all it glory and not a much watered down versions that we are used too. I also look at some of the issues around using uncompressed 4K video and whilst is brings you the real quality you may need to upgrade more than just your camera.
Link to video https://www.youtube.com/watch?v=b8xFOTc6mLY
Alas poor HD camera, I knew it well….
Like it or not but 4K will become new standard for video in the coming years.
But for the early adopters amongst you out there, there will be a more current dilemma.
Do you go with the average quality or the best quality.
In this video I’ll tell about the two different types of 4K video camera available and which might be best for you.
Now unless you’ve been living under a rock for the last year or more, you’ll will have heard about 4K or it’s near equivalent UHD (Ultra Hi Definition) which is exactly double the size of HD, though most people call them both 4K.
The main reason why you would want upgrade from HD to 4k is because of the higher resolution and the quality this brings, even if the final result is only going to be shown in HD. The higher quality source material will still make for better end results.
However not all 4k cameras are created equal.
Although much of the marketing hype might make you believe just buying any 4k camera will give you the best possible quality there are two different types of 4k camera.
The first one is the consumer range cameras. These will be the replacement for the HD camcorders and smartphones we have now. They are going to be 4k or UHD resolution but they will still be using video compression like H.264 or H.265 when it becomes more widely adopted and Chroma subsampling of 4:2:0 which makes use of just a quarter of the colour information picked up on the cameras image sensor.
Cameras like this currently include the Panasonic Lumix GH4, Sony FDR AX-100 and the soon to be released Samsung S5 smart phone. In the future most 4K cameras will fall in to this consumer range bracket.
If your shooting normal scenes which are not going to have much post processing, colourising, not shooting for green screen or visual effects then these 4K consumer video cameras or smartphones are not only cheaper but will give you and excellent hi res output.
The problem is with the compressed output, now while it reduces the file size dramatically it also cuts out the fine detail in the image and this is why many of us want 4k in the first place.
You can think of video compression like the tone control on a hi-fi system. The more you turn down the treble the more of the fine details in the high frequencies are lost.
This is the same with the video footage, the more compression that is applied the smaller the files sizes become, but the more of the fine details are lost and the clarity of the image reduces.
With the current capacity of SD cards and internal memory in tablets and smart phones, this is essential because without compression the file sizes created by 4K are huge, easily running in to many gigabytes of data per minute of recording time. This could fill 64Gb of memory for example, typical in top end tablets and camera cards in 10 minutes or less.
To the human eye the compression maybe barely noticeable but when you are doing things like Chroma key or Visual effects, you are working on a per pixel level which YOU may not see but the things like Chroma key software certainly will see.
If you use a 4k camera with a compressed video out then you’re not going to be getting the full quality, in fact you have to downscale it to HD to get rid of most of the effects of compression and the Chroma subsampling.
So in reality when you have downscaled your 4k compressed output video to HD, it will only produce a similar quality to that of a normal HD video camera that has an uncompressed video output like a Blackmagic Pocket Cinema Camera for example.
This is why, if you want the best output for post processing or VFX work then you need the other type of 4K video camera. This is at the moment the semi-pro 4K video cameras that can output 4k in an uncompressed format like Pro res 4:4:4, 4:2:2 or CinemaDNG raw.
These cameras also have a higher bit depth of 10 or 12 bits of data compared to 8 bit which is the norm for consumer video camera range. This gives much better gradation from light to dark as you have 4096 levels for each colour in 12 bit and 1024 levels for 10 bit. Compare that to just 256 levels that you have for 8 bit outputs. Again this affects post processing and VFX work, but it also give you much more control if you are going to be doing colour grading to the video output.
Until just over a year ago this type of quality output was reserved for Professional cameras like the RED scarlet, Arri Alexa and canon C500 for example, all of which cost north of $30,000.
Then came along Blackmagic Designs with first, the Blackmagic Cinema Camera 2.5k, and that’s the one I’m using right now to record this and then just recently the Blackmagic 4K production camera.
At under than of $3000, less than 1/10th the price of the pro cameras, it’s is getting close to the main stream 4k cameras but with a professional quality video output.
At the moment there isn’t much competition to the Blackmagic 4k Production camera in the price bracket but that’s sure to change at some point in the future. For now the nearest would be the Panasonic GH4 which can give you an uncompressed output in 4:2:2 in 8 or 10 bit depth but you will have to use a separate recorder to capture it from the GH4’s HDMI port, because it will only save compressed video to the SD card.
Which type of 4k camera will suit you the most will be much more down to what you’re going to do with it. If you intend to shoot Chroma key or have a lot of post processing then the cameras with an uncompressed output will suite you best.
However, there are down sides to the uncompressed video output though, one of the main ones is that they create huge files, especially if you shoot them as CinemaDNG raw files.
This not only requires much bigger hard drive storage but all that extra data takes its toll on your computer.
You need a powerful CPU with lots of RAM in order apply effects like Chroma key to uncompressed video and rendering them with an alpha channel takes much longer than the smaller but lower quality compressed H.264 files.
So yes, while we are getting 4k it comes with compromises. Until someone makes a camera that combines both the lower cost and ease of use of the consumer range and has the option of the uncompressed, high bit depth output of say the black magic 4k production camera, we are going to have to choose between two camera types or buy two cameras.
Are you facing this dilemma with your potential 4k camera setup ?, if so let me know what you’re looking to do in the comments below.
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So, my names Paul Shillito and this has been a video alchemy production, so hope to see you in the next video, byeeeeeee.