Small 4K TV vs. iMac 27'' retina

What are you using it for?

winkyincanada posted:

What are you using it for?

Just for occasionally watching concerts (Digital Concert Hall, mainly), a little bit of opera and some DVDs. No television and no sport. I was very happy with a 10 years old 24'' iMac. But the DCH must have changed their encription or compression scheme earlier this year. Watching non-free DCH contents fullscreen is now virtually impossible on the old iMac (free DCH contents are still fine). Thus, I need something new. I want to be able to connect to the Naim DAC via optical. I am also looking for a device that I can easily move out of the way. Hence a new iMac or a small tv.

The iMac has a stunning screen, but if you don't use it for anything else, it's a bit of a waste. For a small TV, 4K is a waste, unless you're sitting VERY close (and watching currently rare 4K content). Dunno, it's a bit of an apples and oranges comparison.

Better than tripping down the apples and pears...

I might be very ignorant and uneducated on this subject, but why would 4k on a small screen be waste, and hires audio not?

Why do we - Naimees - focus so much on all audio details and does the majority of audiophiles on this forum not or at least less care about pixel density (assumed consensus)?

You are going to be told that our eyes are not capable of resolving the detail of 4K on a small screen. This is what the evil company do with their retina branding. They claim that it is better than the human eye. But then we like our stereos to produce sound that we can't hear.

It all depends on the distance you view from. (And whether other people also view, and whether you want the video to integrate spacially with the sound.)

A 27" Mac retina display (5120x2880) has a pixel pitch of 218 per inch, wheareas that of 42" 4K tV screen (3840x2160) is 105. So for the same apparent size pixel seen by your eye the 42 " would have to be about twice the distance from you. But if further than 1.5x the distance from you, the effective size of the screen to your eyes will be smaller, so twice the distance will be a smaller image, or the same size image will be bigger pixels so potentially less sharp. I.e. not as good. 

That's only part of the story. There is a physical limit to the size object the human eye can discern, which will be twice the size twice the distance away. So if the viewing distance for the 42" 4K  is far enough that you can't resolve the pixels, then the 27" retina display 2/3rds of the distance away for the same size image would offer no benefit in resolution.

(That doesn't mean they'd appear identical, as other factors including colour saturation and relative brightness etc all come into play.)

In terms of practicality, this image I posted recently on another thread may be of relevance, the retina display resolution requiring another line below the purple one, right hand end about the bottom of the number 4 of 4k. It would seem to suggest that if your eyes are more than around 2ft from the Mac's screen the resolution is wasted on you, similarly once you're more than about 3ft from the 42" 4k. The primary benefit of the high resolution of the retina screen would seem to be for fine graphic work, rather than movie watching.

Forgot to add it depends on the source material, and I was focusing on movies, for which if the content is 4k the retina screen is probably worse as it has to interpolate.

Innocent Bystander

I have seen your other post, and this diagram is a good and logically quite correct diagram.

What I don't get, is that we - naimees / audiophile - care about the details in music we can't hear but obviously have a certain effect on us. But for video, a different law seems to be there. On video, we don't care about pixels we can't see. Why is that?

Can't it be the case that watching a 4K screen on e.g. 4 meters distance makes me less tired? (given good quality source)

I can't answer definitively as I don't know enough about it. our ears and eyes do different things: we see an image of the space in front of us, in a different form of detail than a photograph - more detail in some ways, though a camera can catch more fine detail - which of course we can with a magnifying glass. Our ears tend not normally to form an image of the world they are hearing - close your eyes and you can't 'see' what is around you, though you can visualise, say an orchestra playing the music (actually apparently some blind people do actually create an image akin to 'seeing' by making small noises and learning to image from the echo information, like a bat, but that's another subject.) What our ears do especially when listening to music is very different from viewing a picture in front of us, and in the case of a motion picture we are simply following a story, with all the information and cues of the film location and acting presented to,us, and the only interpretation is interpretation of meaning of people's actions and words  just as in real life, and the subtleties are the subtleties of real life, just as when you walk into a room and take stock of what is there -  whereas music is abstract.  

Whether this ramble has anything at all to do with it, I don't know! 

And your eyes are easily fooled - even into thinking that something as low as 25 frames of photos a second is a moving image, while colour distortions happen so easily - stare at a coloured object for a minute then at a white piece of paper and you will 'see' its it again in a complementary colour, or wear tinted glasses and you soon adjust and think everything looks normal until you take them off. I'm not sure your ears are fooled anywhere near as easily - witness early days of reconstructing digitised sound.

Innocent Bystander posted:

Forgot to add it depends on the source material, and I was focusing on movies, for which if the content is 4k the retina screen is probably worse as it has to interpolate.

I thought that interpolation was, generally speaking, straightforward and extrapolation problematic. What's the problem with interpolation?

When I use my old 24'' iMac as a tv, I am at about 7 feet from the screen. I understand that at, this distance, a 27'' 5K  screen and, perhaps, even a 40'' 4K screen would not bring any advantages over a full HD screen. Still, assuming that I am willing to pay for nothing, what are the pros and contras of an iMac vs. a 2016 smart, (almost necessarily) 4k, tv? I understand that I  can easily connect a tv to a blu-ray player (which I cannot do with an iMac) and that I can use the iMac to browse https contents (which I cannot do with all tvs). Also, I can connect an audio class 2 device (a Meridian Explorer, for instance) to an iMac but not to a tv. Any other pros and contras of iMac vs tv?

nbpf posted:

Innocent Bystander posted:

Forgot to add it depends on the source material, and I was focusing on movies, for which if the content is 4k the retina screen is probably worse as it has to interpolate.

I thought that interpolation was, generally speaking, straightforward and extrapolation problematic. What's the problem with interpolation?

Not sure if we're talking about the same thing? I was referring to image interpolation, where the screen is more pixels wide than the image, spread 3840 points of information across 5180 pixels, as opposed to motion interpolation, filling in alternate frames between the existing ones. I'm notbsaying its a problem per se, but native resolution is better so a 4k image on a retina screen might not look as good as on a 4k screen. But it will depend on the software doing the interpolation, and I haven't compared for myself, so not necessarily something you would notice.

Innocent Bystander's image definition diagram is really very helpful indeed in helping to decide what size & definition of screen to go for.

However, are we (my wife and I) the only people with superhuman vision?  I ask because we can detect the differences in definition at approximately twice the distance that the chart indicates.

So, either we have superhuman vision (unlikely,  though I so wear glasses so have twice as many lenses!) or we can detect a better picture even if we cannot "see" it.  Is anyone else so blessed?

Best regards, FT

I'd like to add that the improvement of UHD over FHD in many cases is much less important than things like refresh rate, the 'blacks', contrast etc ...

So 4k / uhd is in many cases a marketing term and overrated i.m.o.

What about browsing internet contents? Are browsers in new (2016) Sony, Samsung, etc. TVs nearly as usable as Chrome, Safari, FF on a computer or on a tablet computer (assuming that I have a keyboard or a tablet connected to the TV, of course)? 

Innocent Bystander posted:

nbpf posted:

Innocent Bystander posted:

Forgot to add it depends on the source material, and I was focusing on movies, for which if the content is 4k the retina screen is probably worse as it has to interpolate.

I thought that interpolation was, generally speaking, straightforward and extrapolation problematic. What's the problem with interpolation?

Not sure if we're talking about the same thing? I was referring to image interpolation, where the screen is more pixels wide than the image, spread 3840 points of information across 5180 pixels, as opposed to motion interpolation, filling in alternate frames between the existing ones.

It's the same problem: in the first case you have to fill in a pixel by interpolating between two (or perhaps 4) neighbor pixels, in the second case you have to fill in a picture by interpolating between two neighbor pictures. I might be missing something, of course. But interpolation is interpolation and is not problematic. Attempting at sharpening a picture, of course, is problematic no matter whether this is done by preserving or increasing resolution.  

I think the theory regarding viewing distance totally bogus. You can spot a TV with a top notch display from a long way off.

 TV manufactures usually produce ranges of TV’s of differing quality, the smaller TV’s will be lowest quality, the larger will be highest quality. I doubt you will get a high quality 4K TV as small as 43”, it’s something you’ll need to check if you’re after the highest quality picture.

Interpolating berween two images is not an issue (theoretically) because it is only matter of creating an image that is halfway between the two others, and the two others are unchanged. With pixels, unless a simple multiple, none of the pixels will be exactly an original, all will have to be some interpolated value. But if done well of course it shouldn't be evident.

Innocent Bystander posted:

Interpolating berween two images is not an issue (theoretically) because it is only matter of creating an image that is halfway between the two others, and the two others are unchanged. With pixels, unless a simple multiple, none of the pixels will be exactly an original, all will have to be some interpolated value. But if done well of course it shouldn't be evident.

You are right, I see the point now. Thanks for the explanation! Best, nbpf

fatcat posted:

I think the theory regarding viewing distance totally bogus. You can spot a TV with a top notch display from a long way off.

 TV manufactures usually produce ranges of TV’s of differing quality, the smaller TV’s will be lowest quality, the larger will be highest quality. I doubt you will get a high quality 4K TV as small as 43”, it’s something you’ll need to check if you’re after the highest quality picture.

I realize that 43'' is considered small nowadays and that manufacturers tend to apply their newest technologies on larger TV sets first. This is one of the reasons why I am considering an iMac as a valuable alternative to a small TV.

The main reason, however, is usability. I have read terrible things about the usability of internet browsers on even the most recent Sony and Samsung models. Internet browsing is relevant for me since I plan to use the TV to stream videos from sites (like theoperaplatform, for instance) for which specific (Tizen, Android, etc.) apps are not available. On the other hand, the current iMacs cannot be used as monitors and lack support even for target display mode. It is to be expected that even the new iMacs (rumored to appear later thsi year) will not bring any improvements in this respect.

Thus, my main concern at this point is usability, not picture quality. Ideally, I would like to buy a device which is usable (for my purposes, plese see above) and has a great picture quality, of course.

The only 'smart' TV I have is a 2 year old LG 37", and on its own it is very cumbersome, most particularly if you have to enter text, though that is much improved if you use a wifi keyboard, but still short of the capabilities of a computer. However, you can link to it from a mobile device and p, for example readily play utube videos, though beyond that Which I've done a handful of times there hasn't been anything else I've tried to do with it. I know I can browse the internet on it, but having other devices that can do that I've never even been tempted to try. If you mean to have a single device that can be used for efficient internet browsing and fir watching TV, then the choice would seem to be down to which of the two has priority, good internet browsing efficiency, or a screen big enough for enjoyable viewing from possibly from a greater distance or potentially by more people. AFAIK most people use a TV primarily for watching broadcast TV or movies from whatever source, and a computer of some sort (incl  laptop/tablet) for serious internet browsing.

Hi NBPF,

I did some checks last night on the browser of my Loewe Art UHD. It is also not flawless. The majority of (media) sites work correctly, but I had a few hickups. I would say it works for 80% ok.

Sound quality for a TV was absolutely fantastic, but when I played the sound from the telly using the coax cable into my Supernait, there was an incredible step forward.

I will check theoperaplatform for you today, I assume there are some free examples on the site.

Did you consider a TV + a Mac Mini? Recent Mac Minis do output 4k via HDMI and include audio. Quote from apple: 'Which type of audio works with Macs using HDMI?

Apple supports 8-channel, 24-bit audio at 192kHz, Dolby Surround 5.1, and traditional stereo output.'

TV + Mac Mini gives you all flexibility ...

IB, AEDBEG10Y, Thanks for your feedbacks!

@IB: I would of course keep on using my laptop and/or tablet for everyday internet browsing. The point that I was trying to make is that I do not plan to watch traditional tv channels, netflix, etc. I only need a device for occasionally (say, onece in a weel) streaming concerts (DCH, GSO), opera broadcasts (Wiener Staatsoper, theoperaplatform) and perhaps a few youtube video. Thus, it is important that the device has excellent support for HTML5, Flash, etc.

@AEDBEG10Y: I would be grateful if you could check theoperaplatform, it is completely free. The crucial point, however, are non-free contents: I have no problems watching DCH trailers and free-concerts on a 10 years old iMac. But I need a faster CPU to stream DCH contents that I have payed for! On the 10 years old iMac, I get massive frame drops in fullscreen mode. Thus, I need a new iMac or a TV. I have considered the possibility of buying a Mac mini and a TV (or a big computer monitor). But I am looking for a solution that I can easily get out of the way when not in use (I do not want to have a big black screen permanently in my living room). From this perspective, a new iMac or a TV seem a better option.