When editing your photos, a good monitor is very important. But which one do you choose? A screen with 4K resolution? That is a good choice, because 4K has more benefits than you might think. We explain it in this article.
A few years ago there were discussions whether the difference between HD and full HD in the living room could be seen. That was not always the case before. Large TV screens have since become a lot cheaper, so full HD offers real benefits in many cases. With regard to 4k TVs, however, that question rises again. If you stay away from the screen far enough, you will not see any difference between 4k and HD.
For this you have to be at a distance of less than 133% of the diagonal of the screen. The bottom line is that someone with an average visual acuity only sees difference at 2.4m or closer on a 60 inch screen. Even if you belong to the 1% of the population that sees twice as good as the standard, you should still be two meters away from a TV with a 40 inch screen to see a real difference.
Therefore, the average living room layout is very 4k unfriendly. Children have a good solution for that: they just sit very close to the TV. Unlike in the time of the hazardous CPTs (tube televisions), this is therefore only advisable. Naturally, larger screens will also make the full resolution of 4k visible at a comfortable distance, but for the time being there is still a hefty price tag. As far as the curved screens are concerned, these only offer benefits if you are close enough. Still, the discussion about 4k when buying a TV is getting useless, because good new TVs are 4k anyway.
Everything is better organized in movie theaters. You are often sitting on less than half of the diagonal in the 'row of neck cramps' and at about three quarters in the middle of the cinema. Movie theaters have invested heavily in 4k projection in recent years (partly via lease), so in movie theaters you can see films in higher quality than at home. Just like in the living room, however, people tend to choose the worst possible position in the cinema: in the back. That might have been nice when you went out with your girlfriend / boyfriend at the age of fifteen, but if you want to enjoy the movie, it's a waste of money for the ticket. The middle of the movie theater is about optimal, but at the front can be more attractive in some respects, at least if you do not have a short neck. If you have a fairly large wall without a window at home, you might want to consider buying a 4k projector, because this easily leads to visible 4k quality at a comfortable distance.
In the movie theater and with projectors, we already see a technique that is only reluctantly introduced to TV's: HDR. In theory, it could work much better with TV's, because the contrast is even bigger there. We know HDR from photography and basically it works exactly the same with TV's. An important condition, however, is that the entire chain, from film recording to TV uses the same system for HD. For the time being, this is a problem. Samsung has its own system, but has also joined the HDR 10-grope. HDR 10 is open source and is also supported by Sony, LG Panasonic and others. Since it is free, you may assume that more and more TV manufacturers are going to support it.
On the other hand, there is the technically much better but very ambitious Dolby Vision, which is now supported by LG OLED screens. In short, 4k is commonplace with TV's, but the big changes will be in OLED and HDR in the near future.
When filming, the advantage of 4k is much clearer. First of all, even if you produce for HD, the extra resolution on HD is visible. An old rule in film production is that you need about twice the resolution of your final format. Another important reason to also shoot HD productions in 4k is zooming in when editing. With editing software such as Adobe Premiere you can make very nice slow zoom movements that you can never manage with a camera. Only: that way you lose resolution, of course, so you must start with an image that is clearly sharper than HD.
In any case, it is wise to make recordings in the resolution that will soon be standard (4k) for important events or assignments, because in a few years HD material will be old-fashioned. Probably we will use such big screens in about five years time that an HD movie will look like the Zapruder Super 8 video of Kennedy's murder: a film that is so out of focus, that you think it is an enlargement. There is also a fourth important argument for a 4k camera that has nothing to do with filming. This allows you to distill 15, 30 or even 60 images per second from the movie recordings. You probably think this is four megapixels, but that is not true: 4k is eight megapixels.
What is 4k exactly?
There are in fact two 4k standards. Originally, 4k meant the DCI 4k standard, which has 4096 × 2160 pixels. This is the standard for the film and TV industry. To make it complicated: most films are projected in 3996 x 2160 pixels. UHD-1, also called ultra-high-definition television (UHDTV), is the 4k standard for TV’s and computer monitors. This image is slightly less wide, but equally high: 3840 x 2160 pixels. In practice we use this format, except for very professional equipment and projectors - which of course can also project UHDTV. For the sake of completeness: there is also 8k, twice as much in the width as in the height of the regular UHD, but we do not see that yet in the affordable hardware and there is virtually no content for 8k.
As we have seen, it is very doubtful whether you see the difference between HD and 4k, because most people are about three meters away from a TV with a diagonal of one meter. Compare that with a computer monitor. These are also getting bigger, 30 inches is no exception and 24 inches is pretty normal. Here the situation is reversed: almost no one is more than eighty centimeters away from the monitor and thirty to forty centimeters is very common. Here, therefore, you almost always benefit from a 4k resolution. But what advantage is that exactly? After all, you can zoom in to 100% with an HD monitor to see all the details.
If you also work with a 4k-monitor, even if only for a short while, you will soon notice that it is different. With a 4k monitor you can see your photos and movies not only sharper, but also in a different size than with an older or simpler monitor. There are two major differences:
When you see the screen in its entirety, you can see almost the entire sharpness of the photo at 4k at 24 megapixels. (At 16 more, at 36 a little less). The difference with HD is striking: it seems most like a very large print of your photo.
When you want to see a 24-megapixel photo on an HD monitor, you need to zoom in a little more than three times to see the image at pixel level. Only at that level can you properly assess the sharpness, the noise reduction and the sharpening. With a 4k monitor, the magnification at 100% is much smaller: approx. 150%. So you see the effect on almost the entire image and that is something very different from the effect on a detail of it.
A 4k monitor also displays your photos very sharply when you do not see them at 100%, but for example at 66.13% or at 29.85%. With an HD monitor, except for a very good one, the sharpness is only good for a whole or a whole multiple of 100%: 25%, 50%, 100%, 200%.