Retina iMac 4k Quicktime scaling problem

Question

Retina iMac 4k Quicktime scaling problem

I have just begun using a retina iMac. I notice FCPX scales videos so they appear correctly - a 4k image doesn't fill the screen, and 1080p is quite small. Photos in Aperture appear much the same as FCPX. Great! However in Quicktime, a 4k video appears exactly as it does on a 2.5k iMac: nearly half the image is cut off because 4k is so gigantic - but the display is 5k. Why is this a problem? I assume that Quicktime (7 or X) is not written to scale properly. Nor VLC. So how do I watch the 4k video I just shot and edited?

iMac with Retina 5K display, OS X Yosemite (10.10.1), null

Posted on Dec 24, 2014 4:13 PM

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Answer 1

Jon Walker

Level 6

19,489 points

Dec 24, 2014 6:34 PM in response to This is the real me

However in Quicktime, a 4k video appears exactly as it does on a 2.5k iMac: nearly half the image is cut off because 4k is so gigantic - but the display is 5k. Why is this a problem?

I believe the QT apps are, by default, displayed at a 72dpi equivalent scale.

So how do I watch the 4k video I just shot and edited?

Most people would probably scale the player window manually or use the Command-F or Command-3 keyboard shortcuts to limit display to "fit" within the screen area when using QT X and/or QT 7 Pro players.

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Answer 2

Jan 2, 2015 9:20 AM in response to Jon Walker

Thanks for the reply, Jon. It seems much more complex than you would ever imagine, particularly to a filmmaker working in 4k. The work to be done is enormous. Consider this: even though FCPX scales and 4k is great, at the 4k scaling, SD is so tiny that it's a problem to work on. Most of our TV broadcasts are still SD. So that's a picture of things working as they should.

In apps that *don't* scale, it seems unlikely I am currently seeing anything more than 2.5k. We still can't see our work at actual size. VLC indicates it will display full screen at 2.5k. There is no other option. QT7 and QTX both seem to display video exactly the same way. I could be wrong, but I'm pretty positive we are locked into 2.5k without in-app scaling. For a lay person viewing, it's fine - although notably, the 4k camera is still pretty pointless if no one can view in 4k. We might as well continue shooting 2.4k video because it will be sharper and more detailed at full screen than shooting on 4k. More on that here: http://bradbell.tv/filmmaking/bmcc-vs-bmpc4k-detail-comparison/

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Answer 3

Jon Walker

Level 6

19,489 points

Jan 2, 2015 10:57 AM in response to This is the real me

Thanks for the reply, Jon. It seems much more complex than you would ever imagine, particularly to a filmmaker working in 4k. The work to be done is enormous. Consider this: even though FCPX scales and 4k is great, at the 4k scaling, SD is so tiny that it's a problem to work on. Most of our TV broadcasts are still SD. So that's a picture of things working as they should.

In apps that *don't* scale, it seems unlikely I am currently seeing anything more than 2.5k. We still can't see our work at actual size. VLC indicates it will display full screen at 2.5k. There is no other option. QT7 and QTX both seem to display video exactly the same way. I could be wrong, but I'm pretty positive we are locked into 2.5k without in-app scaling. For a lay person viewing, it's fine - although notably, the 4k camera is still pretty pointless if no one can view in 4k. We might as well continue shooting 2.4k video because it will be sharper and more detailed at full screen than shooting on 4k. More on that here: http://bradbell.tv/filmmaking/bmcc-vs-bmpc4k-detail-comparison/

Sorry, I must have misunderstood what you wanted. I assumed you simply wanted to be able to view the 4K file in QT on the monitor. Apple's recommendation to retain compatibility with all monitors is to limit the target export dimensions to one half the resolution of your Retina screen. Since that would seem to defeat the purpose of creating a 4K video, I assumed you merely wanted to "fit" your 4K content to the "useable" display area of your 5K monitor as limited by the rendering software—which as both you and Apple have pointed out would be 2.5K for your 5K monitor. The suggestion I made simply scales the QT player to fit the maximum display area of the monitor in use. If you want to view your content at the full 4K resolution, you will need an 8K Retina monitor.

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Answer 4

Jan 3, 2015 11:56 AM in response to Jon Walker

Thanks again, Jon. Do you have any links to more info? I think I might be missing some fundamental knowledge about retina displays. For example, "Apple's recommendation to retain compatibility with all monitors is to limit the target export dimensions to one half the resolution of your Retina screen." That doesn't mean anything to me. I just deal in standard pixel dimensions - 576i, 720p, 1080p - and care nothing for density. In other words, I know what Retina means, but I don't see why it's relevant to image sizes, other than to note that images will appear smaller, which is fine.

I believe the key question is: why is the retina iMac so good for 4k-5k photography - allowing me to see my 5k images at actual size, looking incredible - but so limited for 4k video - presenting no way to view at any higher resolution that 2.5k. Is it simply that it doesn't have the horsepower, so it's cutting the display resolution in half? I can't imagine any other logical explanation.

On the other hand, I wonder if I'm supposed to be embracing some kind of resolution-independent future where resolution is so high it no longer matters. That sounds vaguely plausible, but if you want to work on your image - perhaps sharpen it a little - you don't want to be doing it at the wrong display resolution. It would be like sharpening all your images because you don't know you need glasses.

For background, I have a 2nd camera that shoots 4k raw. I decided to keep it because I was expecting a 4k iMac. I thought once I could see 4k at actual size, I'd judge whether it was worth keeping the camera. I can't imagine buying a dedicated 4k monitor to find out. 4k is starting to look a lot like 3D cinema - or an Internet of Things run by the NSA ;-)

cheers,

Brad

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Answer 5

Jan 3, 2015 12:09 PM in response to This is the real me

Actually, I have just learned something. I have the non-retina and retina iMacs sitting next to each other. In QTx, viewing the same 4k video full screen, at actual size - whose edges extend far beyond the edges of the screen - I can see the retina iMac renders the text slightly more cleanly. I'm not sure what the implications of this are because as soon as I size the videos to fit the screen, the difference in rendering disappears, wiped out by the need to shrink the video to see the whole frame. Very strange situation.

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Answer 6

Jon Walker

Level 6

19,489 points

Jan 3, 2015 3:15 PM in response to This is the real me

Do you have any links to more info?

Not really sure what you are looking for here. Looked into the topic of Retina displays 3 or 4 years ago when dealing with images and movies displayed in iBooks and ePUB files on mobile devices. Did not keep the URL for an article I found which explained the doubling algorithm. Nor did I keep the URL for the Apple page that recommended halving images for full screen devices using Retina displays. (Article was probably archived years ago.) Current FAQ for using a Retina display is http://support.apple.com/en-us/HT5266. This article does mention a number of the Apple apps which are "Retina" supported but neither of the most current QT media players appear to be mentioned. Unfortunately, it does not go into much detail regarding the differences in object vs text display other than a brief image of the text scaling differences. As to controlling the "scaled screen resolutions," you may want to look over an old article at http://www.everymac.com/systems/apple/macbook_pro/macbook-pro-retina-display-faq /macbook-pro-retina-display-hack-to-run-native-resolution.html. It mentions three third-party utility options that are supposed to have the ability to allow users to access the actual "native resolutions" of their Retina display monitors (i.e., does not rely on app to be programmed with Retina display handler). Maybe one of them can help you display the 4K content in the manner you desire.

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Answer 7

Jan 7, 2015 8:34 AM in response to Jon Walker

Thanks again, Jon. One great thing I found in the links you provided:

In System Preferences > Display

If you hold the Alt key down you get all sorts of resolution options including 5k.

Living with the retina Mac over time shows scaling occurring in unexpected places. Vimeo, for example scales full screen playback. In any case, it seems to require trust, faith, experience and patience. Thanks for the help!

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Answer 8

Jon Walker

Level 6

19,489 points

Jan 7, 2015 1:04 PM in response to This is the real me

Living with the retina Mac over time shows scaling occurring in unexpected places. Vimeo, for example scales full screen playback. In any case, it seems to require trust, faith, experience and patience. Thanks for the help!

If you were able to glean anything useful, then it was a pleasure to help. Believe the main problem here is the fact that it takes time for software providers to recognize the need for and then add specific support for Retina displays.

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