Will upconverting 1080p videos in 4k TVs, lower their quality?

[tiz___yab]

I read somewhere its better watching 1080p content on native 1080p (Full HD) TVs, because they keep ORIGINAL video resolution without down/up-converting .

If that's true, so buying 4k TVs without any much 4k sources around (While many FHD and HD contents available) , mean wasting both money and quality, isn't that?

On CNET's article:

we've found that 1080p Blu-ray upconverted to the 4K screens looks great, although not appreciably better than 1080p on a 1080p TV.

 

[10tacle]

Generally native resolution of the source for what it was coded for is the best because it is matched to the amount of pixels. If you put 1080p content on 4k, it will stretch the video across many pixels making it blurry. Some HDTVs do upconverting which helps improve the quality back to original source (1080p) and can slightly look better doing so. It depends on the capabilities of the source media and your TV.

 

[americanaudiophile]

One of the things you pay for in more expensive 4k TVs is how well the upscale to 4k. You can't really see the additional pixels in a 4k TV unless you are very very close to it. When you buy a better TV you will get fewer motion artifacts, more accurate color, deeper blacks, a better back light and HDR.