Tech behind new iPad's color quality attributed to 30% increase in power usage
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 ]
Comments
"...unwanted leakage of unwanted light..."
Editor!
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.
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.
It's just not normal, my iPad is dropping about 14% battery power in like 30 minutes.
Post hoc, ergo propter hoc.
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."
Post hoc, ergo propter hoc.
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).
Colorgate, Chargegate, Heatgate... CRgate!
Edit: Ooooops... almost forgot Envygate!
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.
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?
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.
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!
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.
Colorgate, Chargegate, Heatgate... CRgate!
Edit: Ooooops... almost forgot Envygate!
What about SelloutGate! That's the only gate that matters, IMO.
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:
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.
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!