iMac - Is the screen HD?

Discussion in 'iMac' started by nylock10, Dec 26, 2006.

  1. macrumors regular

    Joined:
    Jun 26, 2006
    #1
    I was wondering:

    Does my iMac Intel Core Duo 2.0GHz (20" Widescreen) have some sort of high-def chip in it or something?

    If I compare the image quality to a normal LCD screen (lets say playing a game), will the image quality be a lot better on the iMac than the normal LCD screen (with the same settings)?
     
  2. macrumors G3

    clevin

    Joined:
    Aug 6, 2006
    #2
    game's resolution is fixed, doesn't matter how high your lcd resolution might be.
     
  3. Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #3
    The resolution of the iMac screens are:

    17" 1440x900
    20" 1680x1050
    24" 1920x1200

    "High-Def" is a matter of controversy, but generally anything with more than 720 vertical lines is considered high definition. But there's no such thing as a high-def "chip" per se. Hi-def content typically comes in either 720 or 1080 vertical lines... but the vast majority of high-def TVs have resolutions more like 1280x720 or 1366x768.

    If your game can be played at native resolution on the LCD, it will look best, and it will look better than on an external LCD of a lower resolution, generally.

    Does that make sense?
     
  4. thread starter macrumors regular

    Joined:
    Jun 26, 2006
    #4
    Yep, thanks for making it more clear.

    I was just watching some HD trailers and wondering if it was a true-HD image I was seeing.
     
  5. Moderator emeritus

    mkrishnan

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    Location:
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    #5
    Technically the very highest HD resolution is 1080 vertical pixels in each frame (i.e. progressively scanned, i.e. 1080P). The 20" iMac is just a few pixels shy of that, but I'm pretty sure you can view 1080P with a tiny amount of cropping at top and bottom.

    I think the Apple hi-def H.264 trailers are 720P.
     
  6. macrumors 601

    eXan

    Joined:
    Jan 10, 2005
    Location:
    Russia
    #6
    What do you mean by that?

    The HD is usually referred to 1920 pixels horizontal and 1080 vertical. Your iMac can show only 1680x1050 pixels at once. It can play HD (1920x1080) video, but either with cropping sides and bottom of the image, or downscale the video to fit on your screen.

    Only 1920x1200 resolution screens or bigger (23" ACD, 24" iMac, 30" ACD) can show the HD video without croping/downscaling.

    Hope that is clear :)

    Apple offers all HD resolutions.
     
  7. Moderator

    balamw

    Staff Member

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    Aug 16, 2005
    Location:
    New England
    #7
    Note also to complicate things further that most movie trailers are a bit more extreme in aspect ratio than the 16:9 assumption HDTV makes or the 16:10 that Apple screens use, so many HD trailers are actually closer to 1280x640 or 1920x960.

    Thus you should be able to view 1080p trailers on a 20" iMac at native resolution, by cropping a bit off the sides, not the top or bottom. 720p fits on all Mac screens.

    B
     
  8. macrumors 6502a

    Joined:
    Jun 4, 2005
    #8
    i Noticed on my 20" C2D, that in DVD player, the preferences display a HD part along the top, you can click on it and tell the computer what to do when a HD DVD is inserted, on my Powermac G4 i have the same version, but no HD part of the preferences, strange
     
  9. macrumors 601

    eXan

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  10. Moderator emeritus

    mkrishnan

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    #10
    I've got it too... what's it for? In case you somehow rip an HD-DVD or Blu-Ray onto hard drive and play it from there? Odd to include considering there's no support for the drives yet.
     
  11. macrumors 68000

    Joined:
    Mar 12, 2006
    #11
    It's most likely because Apple is a part of the Blu-Ray Disc association.
     
  12. macrumors 6502a

    Joined:
    Jun 4, 2005
    #12
    yeah, but why when the DVD players we have aren't Blu-ray or HD DVD, drives, and i wonder why it doesn't show on my G4
     
  13. macrumors Core

    Dagless

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    Jan 18, 2005
    Location:
    Darkplace Hospital
    #13
    HD is simply a way of explaining to the mass public that a TV is capable of what Macs and PC's have been capable of for the past 10 years. iMac is HD yes. at least 720p.
     
  14. macrumors 6502

    Joined:
    Feb 3, 2004
    Location:
    Upper Mid West
    #14
    i believe that 1080i is the most common 'standard' for being HD.

    can someone tell me what the MINIMUM setting for a screen must be to show 1080i in it's most common form.

    or translate it into terminology similiar to 1600x900
     
  15. macrumors 68000

    Josias

    Joined:
    Mar 10, 2006
    #15
    Actually, also the vertical resolution matters. The iMac is more than "a few" (30) pixels shy of it. It also needs a horizontal res. of 1920, which it lacks 240 of.;)
     
  16. macrumors 6502

    Joined:
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    Upper Mid West
    #16
    does this mean that setting of 1920x1080 is the minimum setting for a 1080 hd experience?
     
  17. macrumors 68000

    Josias

    Joined:
    Mar 10, 2006
    #17
    Yes.

    And 1280x720 is also what is required for 720p.

    1024x768 is not HD.;)
     
  18. Moderator emeritus

    mkrishnan

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    Location:
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    #18
    1080i means 1920x1080 interlaced. So of the 1080 vertical lines, only 540 are sent on each refresh. 1080i content can be played on any hi-def device (all the 1366x768 tv's support 1080i), but if you want it to be scan doubled, so that you're de-interlacing and showing all 1080 lines of each pair of refreshes, then you need the same thing you need for 1080P -- a display of resolution 1920x1080 or greater (subject to the caveats already discussed).

    I don't mean this part to be snide at all.. I do get snippy ;) but not at this moment. I am very new also to learning all of this, because I only very recently got a hi-def television.

    The upshot... or the short version of the answer... is that it really doesn't matter. When you ask blind judges to pick out which image is playing on the 1080p device and which image is playing on the 720p device, or which image looks best, you tend to find that it is very hard to tell the difference. People who've been in blind AB comparisons even say that telling a 480P DVD apart from a 1080P Blu-ray when they're blind AB'ed is very difficult. TVs tend to distinguish themselves more on things like black levels and contrast.

    I'm not saying it's impossible to tell... under the right circumstances, one can. But it's not so worth worrying about as it seems.

    The short answer is that it doesn't matter, and any new Mac has a screen sufficient to play any Hi-def materials reasonably adequately. Whenever you have a choice in a media source, pick as high as you can manage -- that is, get 1080p if you can, get 720p if you cannot get 1080p, and get 1080i if you cannot get 720p. If you can't get any of those, even 480p is not nearly as bad as its made out to be.
     
  19. Moderator

    Nermal

    Staff Member

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    Location:
    Whakatane, New Zealand
    #19
    It's for playing HD DVD content (not Blu-ray) from your hard drive. I'm assuming that it doesn't appear on G4 systems because they can't decode HD DVD fast enough.

    At the moment it's intended for the DVD authors: They can create an HD DVD using DVD Studio Pro and can then play it back from the hard drive to test, prior to sending it off for replication.
     
  20. macrumors 6502

    Joined:
    Feb 3, 2004
    Location:
    Upper Mid West
    #20
    ok, so i just changed my settings to 1920x1080 at 60 Hz

    does that mean if i download a HD trailer I will set it as HD? this is a 10+ year old crt btw
     
  21. Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #21
    I'm so lost....

    Does your 10 year old CRT display 1920x1080?

    Do you have a 1080i or 1080p video?

    Do you have a means of playing that video in full screen?

    If the answers are yes, yes, and yes, then yes, it will be "HD."

    720p is still better than 1080i, though.
     
  22. macrumors 68000

    Josias

    Joined:
    Mar 10, 2006
    #22
    I was just wondering.

    Many people tell me that hardware has been extremely tweaked to deliver 1080 HD. Which is why I'm worried. As soon as Apple updates the Cinema Displays (hopefully the 20" will be 1920x1200), I plan on gettign one for my 360. Is this plain stupid, and should I get a real TV. Consider I'm on a budget of $700, and don't want some cheapo (rap Prosonic or something like that, jsut because it's HD. Samsung and Sharp are good, and so is Toshiba TV's, but they're all really pricey, what should I do?:D

    (Yes, I know how to connect the 360 to an ACD).;)
     
  23. macrumors 6502

    Joined:
    Feb 3, 2004
    Location:
    Upper Mid West
    #23
    under vga display, i changed the settings to 1920x1060 60Hz and it changed and i am currently using those settings.

    i have a video camera that can do 1080i, but i just assumed that since i don't have imovie hd or any final cut hd product and that i don't have a computer monitor declared to be "HD" (like the 23" mac monitor) that it wouldn't be much worth my time to shoot or edit hd material.

    but i do have a hd tv capable of everything i have heard of up to but not including 1080p


    ************edit: my screen setting is now 2048x1280 whatever that means i'm not sure, but my screen is running it
     
  24. macrumors 6502

    zerolight

    Joined:
    Mar 6, 2006
    Location:
    Glasgow
    #24
    There is no special chip that makes any display HD. As others have said, HD is a standard resolution to which HD Movies are produced, and that standard is 1920x1080p. You appear to be confusing TV standards with LCD monitors.

    There are two requirements for a TV to be considered HD-Ready.
    1. It has a native resolution of at least 1280x720 and must be able to display at least 1280x720p movies.
    2. It must have a DVI or HDMI connection that supports HDCP for content protection purposes used in HD-DVD, Blu-Ray, HDTV Broadcasts, etc.

    When it comes to buying a monitor for your Mac, almost any monitor made in recent years will likely meet requirement 1. Requirement 2. will only matter if you want to be able to plug in the HD output from HD-DVD, Blu-Ray, or Cable to the monitor.

    As to the question of what to buy for HDTV, Xbox360, HD-DVD, and so on. A TV. Not a monitor. Most monitors have an aspect ratio of 16:10. TV broadcasts, Xbox360, PS3, HD-DVD, etc all have an aspect ration of 16:9. If you try running these on a 16:10 monitor then they tend to look a little stretched and wrong. Monitors also tend to be optimised to display text and graphics where as the the TV tends to be optimised towards a natural picture for movies. TVs will generally have all the connectivity options you require (HDMI, Component, and occasionally VGA) that most monitors don't provide.

    So if you plan on watching lots of TV, Movies, and playing Xbox360 or PS3 then you really need a nice TV. Sony Bravia's are nice by the way.
     
  25. Moderator

    balamw

    Staff Member

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    Aug 16, 2005
    Location:
    New England
    #25
    While I agree with the HDTV recommendation, you're missing the point. Very little content is truly 16:9. Most movie content is either wider than 16:9 and lots of TV content is 4:3 (yes there is some programming that is available in HD, but only in 4:3, e.g. Scrubs). In any case you'll end up with black bars on the top or sides since the aspect ratio of the program doesn't quite fit the aspect ratio of the screen.

    16:10 displays are closer to 4:3 so that a program stretched to fill the height of the screen will leave narrower black bars on the sides on 16:10 display than a 16:9 display. Don't be surpised if HDTVs themselves start going to 16:10 i.e. 1280x800 or 1440x900 to 1920x1200 to provide a larger area for 4:3 programming. Many LCDs are already a non-native HD 16:9 resolution at 1360x768.

    Turning to Josias' question.
    It's usually not the resolution that's the problem, but given the sheer data rate you start to get into areas where if you're looking at uncompressed data your data pipes will be stressed, and if you use a modern codec like H.264 your CPU will be stressed. Unlike running a desktop at 1920x1080 you need to update the entire screen 30-60 times a second when watching a video. Take my PC, (please!) it couldn't keep up with 720p H.264 playback until I upgraded the GPU to one that has H.264 acceleration.

    B
     

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