Question Can you upscale sd to 4K ?


Standard Member
Have spent the last 2 months looking for a 50 inch tv which I would like to buy from JL or RS but I have one question which I can't find the answer to.

I have read many posts about various TVs can upscale from HD to 4K with varying success rates but most say that the SD picture is not that great, why is that? Why can't you upscale SD to 4K or can you?

I don't need 4K at the moment but more and more TVs are heading this way.
I would like excellent SD picture with some HD viewing, price range around £500 to £600. Smart TV would be nice don't require 3D or curved.

Have looked at many brands not fussed which I end up with as long as it fits my needs.
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All TV's will upscale SD to 4K in that the image will fill the screen. If it didn't you'd see an image in the centre with big black borders.

Note that SD is fairly low resolution now so on a 50inch screen it is like taking a low res photo and blowing it up. Nothing you can do about it if SD is all there is.


Standard Member
In addition to what Sonic67 says, I find it helps with a visual illustration of just how much SD (and other) content is upscaled when displayed in 4K. The TV will do its best but there's only so much it can do when upscaling such poor resolution input to a high resolution display.

In that price range you're going to get the low end of 4K, so the upscaling algorithms likely won't be the best of the bunch. Since SD still is important for you - and perhaps will be for a while yet - you might be better off avoiding 4K TVs altogether until such a time your main source of viewing is at least HD.

Having said that, only you will know if you'll be satisfied with SD on 4K so if possible you should see if you can check out some SD content on the TVs you're considering prior to purchasing.


Active Member
I know this was a few months ago, anyway:

If a 4K TV is said to be poor at up-scaling SD channels, especially the lower bit-rate channels, e.g. the Panasonic CX680, will the situation be improved by using e.g. a YouView box that already up-scales to 1080i/1080p?

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