Tech behind new iPad's color quality attributed to 30% increase in power usage

Posted:
in iPad edited January 2014


A study released on Thursday estimates that the technology used in the iPad's Retina Display consumes 20-30 percent more power to attain Apple's claimed 44 percent improvement in color saturation over the iPad 2.



According to results from a series of tests conducted by display-centric blog dot color, the new Retina Display iPad utilizes advanced filters to improve color reproduction, which forced Apple to bump the output of the tablet's backlight LEDs to maintain a brightness comparable to previous models.



A problem with all LCD displays is unwanted light leakage which translates to inaccurate color reproduction and lower saturation. To solve the problem and improve an LCD screen's range of color, or color gamut, display makers can either boost the performance of backlight LEDs or implement higher quality filters. In both cases the goal is to represent the primary colors, red, green and blue, as purely as possible since these three hues are mixed to create a display's color spectrum.



Based on the test's measurements, Apple chose to concentrate on upgrading the filters used in the Retina Display to more accurately reproduce the primary colors. The new technology resulted in a spike in power consumption, however, because the improved filters let less light through than inefficient versions. This is to be expected, as high quality filters are narrower by design in order to block out unwanted light bands.



The spectrum graph below was taken from a white screen on both the iPad 2 and third-generation iPad in which all primary color are switched on. Reading the results show that the Retina Display features a significant peak at the 450 nanometer wavelength without much change in shape, meaning that the brightness of the color blue has been boosted.





Source| dot color







When the same spectrum measurements are taken with only blue sub-pixels open, the same peak can be seen, however there is also a slight bump at around 540 nanometers. This small peak means that iPad displays leaks a certain amount of green light when displaying "blue" colors.





Source: dot color







What can be seen from this blue-pixel-only chart is that the new iPad allows less green light to pass through the filter which translates into a purer blue.





The iPad 2's display (left) shows a slightly aqua tinge when compared to the new iPad's Retina Display (right) | Source: dot color







As a result of the enhanced color, less light is getting through the improved filters and thus more LEDs or more powerful units are needed to compensate. By dot color estimates, this relates to a 20-30 percent increase in power consumption which is most likely one of the main reasons why the new iPad sports a massive 42.5-watt-hour battery.



[ View article on AppleInsider ]

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Comments

  • Reply 1 of 42
    SpamSandwichSpamSandwich Posts: 28,817member
    Quote:

    "...unwanted leakage of unwanted light..."



    Editor!
  • Reply 2 of 42
    ch2coch2co Posts: 41member
    No way to turn this feature on or off? Most of the time I would rather have 30% longer battery life.
  • Reply 3 of 42
    solipsismxsolipsismx Posts: 19,566member
    Quote:
    Originally Posted by ch2co View Post


    No way to turn this feature on or off? Most of the time I would rather have 30% longer battery life.



    1) No, but you can reduce your backlight brightness, turn off unneeded radios, and use paid apps that don't have ads.



    2) This doesn't mean 30% longer battery life as we're talking about the power usage of the display, not the GPU, not the CPU, the backlight, or anything else.
  • Reply 4 of 42
    tallest skiltallest skil Posts: 42,850member
    Quote:
    Originally Posted by SpamSandwich View Post


    Editor!



    But maybe there's also wanted leakage of unwanted light, wanted leakage of wanted light, and unwanted leakage of wanted light. He's just making sure we know what kind is leaking.
  • Reply 5 of 42
    wardcwardc Posts: 150member
    It's just not normal, my iPad is dropping about 14% battery power in like 30 minutes.
  • Reply 6 of 42
    solipsismxsolipsismx Posts: 19,566member
    Quote:
    Originally Posted by WardC View Post


    It's just not normal, my iPad is dropping about 14% battery power in like 30 minutes.



    Post hoc, ergo propter hoc.
  • Reply 7 of 42
    Quote:
    Originally Posted by SolipsismX View Post


    Post hoc, ergo propter hoc.



    Consumer Reports will say, "we cannot recommend the new iPad because the improved color on the retina display uses 30% more power and despite the larger battery, it is not Android enough to recommend."
  • Reply 8 of 42
    SpamSandwichSpamSandwich Posts: 28,817member
    Quote:
    Originally Posted by SolipsismX View Post


    Post hoc, ergo propter hoc.



  • Reply 9 of 42
    Quote:
    Originally Posted by WardC View Post


    It's just not normal, my iPad is dropping about 14% battery power in like 30 minutes.



    I read somewhere that there may be a problem with the battery indicator displaying an incorrect charge level -- showing 100% charged when, actually, not fully charged.



    One thing to try is charge the new iPad with a standalone charger... then when it shows 100%, monitor the temperature of the charger. If it stays warm, it indicates that the battery is still being charged (it isn't really at full charge).

  • Reply 10 of 42


    Colorgate, Chargegate, Heatgate... CRgate!



    Edit: Ooooops... almost forgot Envygate!
  • Reply 11 of 42
    solipsismxsolipsismx Posts: 19,566member
    Quote:
    Originally Posted by Dick Applebaum View Post


    I read somewhere that there may be a problem with the battery indicator displaying an incorrect charge level -- showing 100% charged when, actually, not fully charged.



    One thing to try is charge the new iPad with a standalone charger... then when it shows 100%, monitor the temperature of the charger. If it stays warm, it indicates that the battery is still being charged (it isn't really at full charge).





    From what I read it can take up an hour after it says 100% to actually be fully charged. Hopefully AnandTech will tackle this issue with precision in their thorough iPad (3) review.
  • Reply 12 of 42


    OT, but related to the recent AI threads on Windows 8 / Metro:



    If Windows 7 "Simplifies" the PC, What Does Windows 8 Do to It?



    Quote:

    When I asked why Metro apps couldn't share the Taskbar with the other Desktop apps, the response I got was that the Taskbar would not always be on-screen. Why wouldn't it be on-screen all the time? Because sometimes you'd be running a Metro-style app.



    Quote:

    In Windows 8, there are quite a few surprisingly detailed procedures for doing things that accomplish nothing whatsoever, this being one of them.



    An interesting read by a pro Windows guy!

  • Reply 13 of 42
    rmb0037rmb0037 Posts: 142member
    SUPER interesting article. Idk about you guys, but I am still drooling at my retina display wallpaper on my home screen. I'll give up " longer battery life" for the improved spectrum of colors. It looks like lit up paper pretty much. SUPER sweet!!!
  • Reply 14 of 42
    toruktoruk Posts: 38member
    It's ironic that I'm viewing this thread on my iPad.
  • Reply 15 of 42
    apple ][apple ][ Posts: 8,360member
    My new iPad screen looks freaking amazing! It's the best screen out there, with very accurate colors and it's also super sharp of course. It's the best screen that I have, out of all my monitors.



    I am not a filthy treehugger and I don't mind using more power for a vastly improved viewing experience. Having characters where you can't make out the pixels when reading is definitely worth any increased power usage.



    I suggest that Apple makes two versions of the next iPad, one for demanding users and for people who want and expect the best. The other version will be for people with poor eyesight and people with shitty standards. Hell, just make the display 64 x 64 pixels, that ought to save a whole shitload of power. Actually, scrap that. Apple does not need to make any low quality, shitty products, their competitors already have that area covered.
  • Reply 16 of 42
    apple ][apple ][ Posts: 8,360member
    Quote:
    Originally Posted by Dick Applebaum View Post


    Colorgate, Chargegate, Heatgate... CRgate!



    Edit: Ooooops... almost forgot Envygate!



    What about SelloutGate! That's the only gate that matters, IMO.
  • Reply 17 of 42
    Quote:
    Originally Posted by Apple ][ View Post


    My new iPad screen looks freaking amazing! It's the best screen out there, with very accurate colors and it's also super sharp of course. It's the best screen that I have, out of all my monitors.



    I am not a filthy treehugger and I don't mind using more power for a vastly improved viewing experience. Having characters where you can't make out the pixels when reading is definitely worth any increased power usage.



    I suggest that Apple makes two versions of the next iPad, one for demanding users and for people who want and expect the best. The other version will be for people with poor eyesight and people with shitty standards. Hell, just make the display 64 x 64 pixels, that ought to save a whole shitload of power.



    ...Anything less than 77 x 77 is totally unacceptable



    or this:







    or this:



  • Reply 18 of 42
    wizard69wizard69 Posts: 12,357member
    Quote:
    Originally Posted by ch2co View Post


    No way to turn this feature on or off? Most of the time I would rather have 30% longer battery life.



    Seriously this is the same as any other lighted device, more brightness means more power.
  • Reply 19 of 42
    cameronjcameronj Posts: 2,357member
    Quote:
    Originally Posted by ch2co View Post


    No way to turn this feature on or off? Most of the time I would rather have 30% longer battery life.



    Yep, just hit settings, general, then you have to draw three figure 8 patterns on the screen which will unlock the easter-egg that will reveal the video quality settings.



    My battery life went up by like 8 hours! Crazy!
  • Reply 20 of 42
    tyler82tyler82 Posts: 669member
    I am very satisfied with my all day iPad battery life. It was actually over 50% last night when I plugged it in at bed time.
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