Reply to post: Re: Dave 126.

'Daddy, what's a Blu-ray disc?'

Dave 126 Silver badge

Re: Dave 126.

>But how does it offer "greater dynamic range"? It is a TV with pre-recorded content, OLED and black is black, white is white. How can they "increase" that via the source data or by changing from 8bit to 10bit colour? They can't. ;)

How? Because UltraHD includes the Rec 2020 colour space specification, at either 10 bit or 12 bit per pixel. The specs cover the content, not just the final display output.

'White' is not the brightest. For a demonstration of a file having more information that the display device, just download a *.EXR or *.HDR image file, view them in PhotoShop (Gimp users need a fork called CinePaint) and play with the slider in the bottom left hand corner - it is akin to adjusting the exposure of a camera. Such files are used as environment maps in 3D raytracing, because light sources depicted in the images have their brightness defined by the extra bits per pixel - thus the rendered object will have highlights and shadows. To a lesser extent, many RAW files will also contain more information than most monitors can display.

If you reread my original post, you'll see that I said that UltraHD TVs have greater dynamic range, not '4K' TVs per se. That was very deliberate distinction, though of course most '4K' sets will soon conform to UHD (the first 4K sets were sold before the standards were finalised).

>The UHD/4K provides better resolution.

UHD is a set of standards that include resolution *and* colour space, including a greater dynamic range.

>The OLED provides better dynamic range. (Black has always been black, white has always been white, everything else is false advertising)

OLED does allow for proper black (each pixel is its own light source), but there are techniques that increase the dynamic range of LED sets (effectively 'local dimming'). LED sets still won't have the absolute black of OLED, but they have greater absolute brightness. This is accounted for by UHD standards.

https://en.wikipedia.org/wiki/Ultra-high-definition_television#Color_space.2C_dynamic_range.2C_and_frame_rate

>TL:DR, the advertisers and marketers are very good at using the wrong words to describe real changes, and you seem to have fallen for it.

I'm not clear what you think I've fallen for. Your post suggests that you think UHD only covers resolution. The idea that 'black is black and white is white' applies to printed images but not necessarily to display devices (or for that matter, stained glass windows).

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