Best way to view a 4K video clip?

[MoodyM]

I have a 4K video clip that I'd like to show off in as best quality as I can on my 15" Late-2013 MBP.

Would it be best to leave the display settings as "Best for Retina" or use some 3rd party tool to enabled the native resolution?

 

[priitv8]

IMHO the video runs at native res independent of the UI rendering settings.
So you won't need to touch anything.
Granted, the 4K video needs to be scaled down, as it is larger than rMBP screen. But that's been taken care of by OS X, you don't need to worry about it.
Just play your movie in fullscreen. It'll be as good as it gets. And both Preview and QuickTime should already be Retina-coded.
PS the pictures are handled similarly.
UPDATE:

Apple said in the Keynote that FCPX is now capable of showing pixel perfect 1080p top right in the viewer with space for a full timeline and the library. It was also said that Adobe are working on a new version of Photoshop for the display - Any apps not capable of supporting the new resolution will be pixel-doubled. No word on Premiere strangely!

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