Search the Community

Yesterday, in the 2019 projectors releases thread, a brief comment was made to the effect that a native 4K projector was advantageous (over a 2K with-pixel-shift 4K projector) if the source was a 4K pc desktop, a 4K computer game, or a 4K animation, because these were "pixel perfect". The comment and my response to it have disappeared from that thread (apparently being considered too off-topic), so I am re-raising the issue here. I think it's important to understand the limitations of even computer generated images when choosing a 4K pj. For the sake of simplicity in this discussion, I'm using 4K to refer to the UHD format 3840 x 2160 pixels. 1. A pc desktop Lines and text on a pc desktop set to 2160p will tend to result in hard boundaries at the pixel level. That effect can be reduced where the application generating the lines and text is feeding a resizeable window. This may involve use of anti-aliased text. See https://en.wikipedia.org/wiki/Font_rasterization If using a spreadsheet full-screen on a 2160p desktop and choosing a very small font size for the cell content, a native 4K projector could indeed be an advantage as it could make the very small font legible when a 2K plus pixel shift pj might make some of the small font characters impossible to make out. (It would be necessary to view the pj screen from an unusually short distance.) For general web surfing using a 2160p destop it should be possible to select a larger font size for text. As for 4K video displayed using a 2160p computer desktop it will rarely if ever contain hard pixel boundaries. (This is to avoid aliases; see discussion below on animation as to why hard pixel boundaries are undesirable.) 2. Pc gaming In the past, games involving rapid movement were often played at 720p in preference to 1080p in order to achieve an acceptable game frame rate. Even with expensive graphics cards today it it can be challenging to achieve fast performance if the desktop is set to 2160p. Because some parts of the game frame may be relatively static, e.g. game statistics, it is possible hard pixel boundaries will be generated by the gaming app. Also because anti-aliasing of movement in a game can use up precious processing resources, and because games typically don't aim for cinematic realism anyway, a game with fast movement may well generate non anti-aliased video, with hard pixel boundaries. In these circumstances a native 4K projector could provide a distinctly sharper look (if in fact the game is run at 2160p). There are strategy games that don't involve fast movement. If such a game aims to create realistic, true to life looking video, it will need to avoid generating hard pixel boundaries. It would be counter-productive for the strategy game app to generate pixel perfect hard edges (unless it was intended that the frames would be subsequently rescaled or otherwise anti-aliased). 3. Animations The closer a computer generated animation comes to looking realistic, the less likely it is to have hard pixel boundaries. It has become common for animations to be integrated into real life camera footage. For example in Avatar (2009) we could see human beings in the same scene as N'avi, the tall blue-skinned CGI generated inhabitants of Panadora. Realistic looking animations are not "pixel perfect". Rather one pixel will bleed into the next. There are no hard boundaries between pixels. This applies whether the animation is hand drawn and photographed in the manner of a mid-20th century Walt Disney cartoon, or computer generated as in the 2018 movie, Jurassic World: Fallen Kingdom. There should be little difference in appearance between a native 4K pj rendering a high quality 4K animation, and a 2K with pixel shift pj rendering the animation because animations are necessarily "soft" at pixel boundaries (to avoid looking artificial with moiré patterns or other aliasing artefacts). So my suggested answer to the question posed in the thread topic is, "No". The following comments made earlier this year on another forum by "Aaron Estrada, C.G. Supe. 20 years in VFX & Animation. DWA, R&H, Imageworks" are relevant. From https://www.quora.com/What-resolution-is-CGI-for-movies-usually-rendered-at :-