Rather than answering a single reader question this week, I'm responding to a series of them. Just about every time we post a 4k or 8k screenshot gallery, we're asked: "What's the point? Why post 4k screenshots if so few people have 4k displays, and why post 8k screens at all?"
It's a reasonable question. Everyone knows their display has a resolution—say, 1920x1080—so it follows that one might have no use for a 7680x4320 image on such a screen. And true enough, if we actually had a display with 73.2 million pixels, the games featured in our Pixel Boost series would probably look pretty damn nice on it. We don't, but there's still a good reason to take super high-res screenshots: supersampling.
As I explained in my article on graphics options, supersampling is the process of rendering an image at a greater resolution than the display is capable of, then shrinking it back down to the size of the screen. The 'shrinking' process is the important bit. When an image is downsampled, each pixel in the final image is composed of data from several pixels in the higher-resolution original. So where there was, say, a jagged transition between a character's nose and the sky, we've now blended multiple nose and sky pixels together in the smaller image, smoothing it out. That's a simple explanation, at least, and in this way, supersampling cuts down aliasing and gives us very clean and detailed images.
So, when we post 8k images, they're not meant to be viewed by zooming in to the full resolution and panning around them, and you'll actually see some ugly, jagged edges doing that. You want your browser or image viewer to downsample the screenshot, so that those jagged edges become smooth and clean. Alternatively, we could just resize the screenshots ourselves before posting them, but we like to offer the full resolution screens for you to view as you please.
There are lots of ways to experiment with supersampling yourself. It's available as a setting in a few games, either as 'rendering resolution' or simply labeled 'supersampling,' and you can also use tools like Durante's GeDoSaTo. Every week in Pixel Boost, we describe the process for a new or old game, and I highly recommend trying your hand at some videogame photography. It's a lot of fun to compose these screens—aside from our column, Dead End Thrills is a great place to look for inspiration.