I realize this write up was for the Q90R but I suspect the same applies to the Q80R.
In particular he makes these observations and recommendations:
"Standard is my favourite, as it delivers a dynamic, bold image that fully exploits the TV’s extensive talents. However, make sure you go into the General menu and turn off the Eco mode, otherwise the picture will become seriously dull when watching in a dark room. I’d advise nudging the backlight down a couple of points, and switching the Colour Space from Native to Auto. You may also feel compelled to push the brightness up one or two points to boost shadow detail. If you do this, don’t forget that you’re also shifting the picture’s colour tone.
I’d recommend, too, either turning off the set’s Auto Motion settings completely, or else choosing ‘custom’ and setting judder and blur reduction to three or four.
The Digital Clean View feature, meanwhile, can be turned off for good quality sources. But it can be helpful in reducing noise if you’re watching a very low quality HD or SD source.
The Movie mode delivers a much less bright and saturated image, but looks more balanced and delivers more shadow detail. It’s designed to look closer to the original mastering values of the SDR or HDR content you’re watching. You need to take a slight yellowy undertone out of the Movie mode via the white balance adjustments to get it looking its best. Otherwise, it’s much more successful than Samsung Movie modes have previously been. So long as you don’t mind only using a relatively limited amount of the QE65Q90R’s colour and contrast potential."