If you have been shopping for a camera, you most definitely have come across the term 4K video listed in the shop or website you are on describing some of the shop products. But what exactly is 4K, and what does it mean in a camera? Be it in terms of televisions or cameras, 4K is a weighty tech topic discussed everywhere. It just refers to a video specification that means ‘4000’ just as its name suggests and gets its name from its approximate 4000 pixels of width worth of footage. To put this statement well into perspective, we will look into the developments that have led to 4K technology and the era before the HDTV revolution.
The earliest screens could display an image with a resolution of 858 x 480 pixels. This was well known as the SD for Standard Resolution. It was also known as 480p, which was informed by the pixels’ number from its pixels of width. You will notice this was the case with most of the different advancements along the way.
After that, we would have the HD ready displays that displayed images at a resolution of 720 x 1280 pixels. This display came to be known as the HD or 720p format. After that, we had a display with a resolution of 1920 x 1080 pixels displayed by true high definition screens. This display would be known as 1080p or FullHD. It is essential also to note that in all the advancements in resolution above, the “p” could be replaced with “i” like 1080i. This is dependent on whether the display is a progressive scan or an interlaced scan. You can read more into this to get more details.
All the said advancements would then usher in the 4K technology. 4K technology can display images at a resolution of 3860 x 2160 pixels. Despite most of the displays getting their names from the number of pixels, in an intelligent marketing strategy, the marketers would then call it “4K” or “UltraHD.” This was because the 4K display has about four times as many pixels as the 1080p or FullHD display.
It is also essential to be in the know about the cinematic standard called “Cinema4K”. This display describes a resolution of 4096 x 2160 pixels with its imagery. The Cinema4K name is informed by the horizontal pixel count that is in its 4000 pixels.
How does this affect video shooting?
What would all the above information mean for video shooters? Well, this would mean many things, one of them being that when you are shooting your video in 4K, you capture 8,294,000 pixels. This goes ahead to show that you are producing footage that is four times more sophisticated than the 1080p. This would also give more room for post-production of the videos, further increasing quality.
When you shoot 4K, your HD videos look like those of superior quality. It is also really beneficial when you shoot with 4K source material then even when you downscale it to HD resolution, the picture looks way better. This is made possible by the productive oversampling of each pixel by four, which makes the images sharper and more vivid. In addition to that, the color grade is easier to grade, and the customary video artifacts are notably decreased or eliminated owing to the initial capture in higher resolution.
It is also possible to enjoy some editing techniques that would be almost impossible with HD capture. For instance, you can crop by up to 4x on 4K footage which was very tricky before when dealing with HD. You are also able to zoom in, zoom out or pan across an image. All these happen while still allowing you to maintain a full HD resolution.
Sometimes after you have shot a video for one of your clientele, they turn out to be needing a still image. What happens then? You need to extract an image from the video to ensure the customer is satisfied. For an HD video, you can only extract a 2MP image from its video, which does not amount much. However, when it comes to 4K, you can extract an 8MP image from the video, which is ample even for a printed ad or advertisement.
During image stabilization, the extra pixels in 4K do turn out to be helpful. Most non-linear editors employ image stabilizing functionality, which is great in stabilizing handheld images. The functionality inevitably decreases your footage quality through calculated cropping, scaling, and rotating your footage. Since this process involves cropping out pixels, the resultant footage will significantly lower quality, especially if you are using HD source material. This changes when using 4K source material since you have many pixels to gamble with!
Editors also, in their video shoots, often employ the use of a green screen. This video methodology is used to help in integrating a foreground subject with a different background inserted later. It is also called chroma-keying and increases in ease with the increase in pixels. This means that using 4K footage would make the process more successful and improve the output quality.
4K For photographers
The benefits of 4K are not exclusive to video shooters and have significant advantages for still photography. Many cameras have a 4K frame grab technology that allows you to film a 4K video and eek a still image from it in UltraHD, a great feature. Some also enable you to hit the shutter button while recording to mark out which frames you want to grab. That is not all; some cameras even make it better with their 4K Photo mode that allows you to film footage in aspect ratios that are more conventional as opposed to the usual panoramic mode in videos. Shooting videos at 30fps for 4K also means that you get more keepers. The term 30fps means a second of 4K footage, and you get 30 photos to choose from.
Some 4K Challenges
Despite all the benefits of the 4K display, you must note some of the challenges you may face while using it. When using 4K, you should be aware that it will exhaust the batteries very fast than its predecessors and cause the camera to run warm because it demands higher processing power. 4K footage also requires a lot more space than HD, up to four times as much. You would also need to use fast memory cards, preferably the U3 rating, to keep up with all the data.