Ender's Game 4K Blu-ray Review & Comments

THX1138UK

Well-known Member
You are lucky as many do whether it's an E6, all the way up to the CX. It's a known issue with the ATV4K. If you watch tv in a totally dark room, it becomes obvious.

I don't have Apple TV, but sounds like it could be outputting computer level luminance (0-255) rather than video level luminance (16-235). Are there any configurable options that let you choose 'Limited' (or 'Studio') level rather than 'Full RGB'?.

Also, you could try outputting Y′CbCr and let the TV do the conversion to RGB (if that's an option in the Apple TV settings). Sometimes the coordinates get messed up in the conversion process.

Regards,
James.
 

Trollslayer

Distinguished Member
By video level luminance you are talking about analogue TV broadcast levels which makes allowance for sync pulses.
 

THX1138UK

Well-known Member
By video level luminance you are talking about analogue TV broadcast levels which makes allowance for sync pulses.

Not really. It's a hangover from the analogue days, but it persists in the digital realm where computers output luminance levels between 0-255 (black is 0), while video luminance for televisions is expected to be in the range 16-235. Values between 0 and 15 are said to be below black. This is still true to day and applies to all sources (streaming, terrestrial TV, Blu-ray etc).

An XBOX (for example) can output 'Full Range' (which you should only use if using a computer monitor) and 'Limited Range' which is correct if you are using a TV (Full Range and Limited Range are terrible names that don't accurately describe what's going on). There's no universally accepted naming - different manufactures call it different things... I prefer 'Computer Level Luminance' and 'Studio/Video Level Luminance' as I think it's clearer terminology.

Regards,
James.
 

wxman2003

Well-known Member
I don't have Apple TV, but sounds like it could be outputting computer level luminance (0-255) rather than video level luminance (16-235). Are there any configurable options that let you choose 'Limited' (or 'Studio') level rather than 'Full RGB'?.

Also, you could try outputting Y′CbCr and let the TV do the conversion to RGB (if that's an option in the Apple TV settings). Sometimes the coordinates get messed up in the conversion process.

Regards,
James.
It's a known issue with the ATV4K. DV is messed up on that device. It's not a bright glow, but a faint glow with all DV material, even in the letterbox bars. It's not outputting computer level luminance. HDR10 and SDR have no issues on the ATV4K. No elevated blacks.
 

THX1138UK

Well-known Member
It's a known issue with the ATV4K. DV is messed up on that device. It's not a bright glow, but a faint glow with all DV material, even in the letterbox bars. It's not outputting computer level luminance. HDR10 and SDR have no issues on the ATV4K. No elevated blacks.

OK, I see. That's a shame. If enough people complain (to Apple) hopefully they'll fix it.

Regards,
James.
 

rebel_scum

Distinguished Member
Man, the audio on this is glorious.

I was able to largely correct the gamma issue by dropping brightness from 50 to 46.

A tenner well spent.
 

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