How Screen Resolution affects You and Your Mobile? -KnowYourMobile Series #1

Before I get into the core of this article allow me to take you way back to the year 2010. It was Summer when Apple Inc. proudly launched their next flagship phone, the iPhone 4. Its main USP was its retina display having a pixel density of 330 PPI.

How Screen Resolution affects you and your mobile- mobilejury

Credits: anandtech.com

Important terms:

 

Pixel

A small illuminated area on a display. Many pixels in horizontal and vertical dimension form an image.

In a colored display each pixel is made up of 3 independently controlled sub-pixels which are R (red), G(green) and B(blue) namely. These are the 3 primary colors and can be used for making any color.

 

Screen Resolution

The screen resolution in digital displays is the number of pixels displayed in each dimension (horizontal and vertical).

The horizontal length is called width and the vertical length is known as height.

 

Pixel density

In context to computer displays, pixel density is the measure of pixels present per unit area.

 

PPI

PPI is the abbreviation used for Pixels Per Inch.

PPI can be calculated by finding the diagonal pixels first using the Pythagoras theorem. The diagonal pixels when divided by the screen size (diagonally) give the pixel density in PPI.

Diagonal pixels= Square root of the sum of squares of width and height in pixels.

PPI= (Diagonal pixels)/ (display size in inches)

 

How PPI became the buzz word?

Tech blogs and magazines started judging phones displays just by calculating their pixel densities. As a result, people started buying phones having high PPI displays. This gave the manufacturers even more reasons to focus on designing phones having high PPI displays.

Since then every mobile phone manufacturer in the world has found itself in a tight PPI race with other manufacturers. The android OEMs soon came up with phones having nearly same or somewhat more PPI as the iPhone 4 but the race didn’t stop there.

I’ll try to keep things simple here. If you are willing to dig deeper then read this article on pixel density by Joshua. He has done a commendable job at explaining such a complicated concept in relatively simple words. Now that you are back here, let’s proceed further.

 

Why Apple termed the display on iPhone 4 as a ‘Retina Display”?

Do you remember the hype created by retina display of Apple iPhone 4?  There is a reason why Apple chose to settle at a pixel density of 330ppi. Apple uses arcminute as a measure to classify display as a retina display.

“1 arcminute means 300 ppi for a display that is held 10-12 inches away from the eyes.”

Actually humans have a practical resolution in the range of 0.8 (children) to 1(adults) arcminute.
Children have better resolving power than adults and 0.8 arc minute also means 375 ppi for a display held at a distance of 10-12 inches from the eyes.

0.5 arc minute is the biological upper bound for the human eyes for resolving 2 lines as separate lines on a display which is held 12 inches away. This also means a pixel density of 600 ppi. Going beyond that will have no effect on the perceived clarity.

There is a clear increase in the sharpness of an image being rendered on the display when going from 330 to 450 ppi approximately. Going any further would have almost no effect on the sharpness perceived by human eyes. If the OEMs choose to cross the 600ppi mark for a smartphone display then it would be purely for marketing purposes.

 

Going beyond 600ppi for a smartphone display would be only for bench-marketing purposes

 

 

How pixel density affects User Experience?

Like I have mentioned above humans eyes can find the graininess in smartphone display up to 450 PPI. The biological upper bound is 600 PPI and to find out the difference in sharpness between a 450 and 600 PPI display eyes with perfect vision are required.

We have prepared a pixel density table for estimating the sharpness of phone displays. Display sharpness cannot be judged only by checking the PPI count. Many other factors play a significant role in making a display look sharp and vibrant.

This table is based on our observations and experiments. Use it at your own risk.

PPI Range Quality Perceived
100-150 Poor
150-200 Acceptable
200-250 Good
250-300 Very good
300-350 Excellent
350-450 Eye popping
450+ Life like

 

Selecting the best phone for your requirements based only on PPI count.

If the phones in your shortlist have similar display tech (TFT LCD, IPS LCD, LED, AMOLED, Super LCD etc) and same protection from scratches then you can use PPI count for selecting phones best suited for your needs.

Check the next post in this series for in-depth information about types and technologies behind different kinds of phone displays.

Most of the mid-range smartphones from local manufacturers have pixel densities in the range of 200-300 PPI. I feel that for reading ebooks and browsing web, a phone with a pixel density of ~250 PPI would be okay. If you like a watch loads of movies and video songs on your phone then you should get a phone having a 300+ PPI display.

 

When the PPI count becomes an overkill

Now you know that paying more money just to get a phone with higher PPI display is a waste. Let’s understand how.

The resolution of any computer screen is limited by 2 factors. The hardware of screen itself and the video card feeding the data to it.

 

Role of a Video Card

The main job of a video card (on-board or discrete GPU) is to deliver data (sub-pixel values) to each and every pixel on the display. More number of pixels means more work has to be done by the GPU.

For e.g- An HD display (1280×720) has 921,600 pixels to feed whereas a full HD display (1080×1920) requires data to be fed to 2,073,600 pixels. Just looking at the number of pixels in a FHD display can give you the idea about how much extra work the GPU has to do as compared to an HD display.

Extra work means more energy is consumed by the graphics card. This means that the battery will drain faster and hence will lead to more heating issues.

Increase in resolution is directly proportional to power drawn from the battery

 

Technically speaking much energy difference is not involved when going from HD to full HD displays but when we talk about the latest 2K displays (2560×1440) then things become a little complicated.

With the current generation of circuitry and display panels (IPS or AMOLED) this transition means significant increase in power draw. The phones sporting such displays have the strongest chipsets but what about the batteries?

 

Battery tech needs a breakthrough

There hasn’t been much innovation in the battery technology since many years. Battery manufactures are only trying to cram in more milli ampere hours (mAh) into the batteries. The smartphone manufacturers on the other hand are busy designing slimmer phones with larger batteries.

 

Don’t expect your smartphones to last more than a day or two

Generally with the technological advancements we get one step closer to making a perpetual motion machine. We all have observed that the newer electronic goods are more efficient than the older ones. Alas, this will not hold true for the latest smartphones at least for the next couple of years!

The main hurdle in the path to achieving superb battery backups from the smartphones are us- the users and the manufacturers.

We, the users are crazy about the display clarity and PPI count so much so that we buy a phone with higher PPI display without even giving a second thought about its battery backup. The manufacturers hence find little motivation for creating phones with great battery backup. They just keep thinking about installing higher resolution display into a phone of smaller dimensions and same battery as the old one.

 

Possible resolution at this point of time

If the phone manufacturers stop focussing on the PPI race then the battery backup will keep on improving with the advancements in the chip architecture alone.

The innovation in battery technology in future will add more usage hours to the battery but till then we have got to stick to full HD displays.

Say NO to 2K displays

 

Over to you

If you like this article then please share it on your favourite social networks. It will motivate me to write more in-depth articles like this.

Which PPI range best suits your requirements? Do you think that full HD displays are more than suitable for anything?

Sources: anandtech, engadget

 

14 Comments

  • Jitendra Jangid says:

    Anand Sir, I think (Not Sure)
    IF Any Mobile has About 200 PPI Display and Any Normal GPU
    Normally Better for Below terms.
    1. Distance for Mobile is 1.5 Feet (18 Inch)
    1. Reading TEXT, VIDEO, ICON and ALL IMAGE OBJECT.
    2. Better for Battery Backup also.
    3. Basic Use in Sunlight.

    YES OR NO, Please Tell me.
    IF Your Ans. NO, Then Suggest We, Which Display Specification
    (PPI, GPU, Resolution, TFT, IPS etc.) Better for .
    1. Distance for Mobile is 1.5 Feet (18 Inch)
    1. Reading TEXT, VIDEO, ICON and ALL IMAGE OBJECT.
    2. Better for Battery Backup also.
    3. Basic Use in Sunlight.

    Please Reply Soon.

    • Anand Karwa says:

      Hi Jitendra,
      For enjoying videos the pixel density should be close to 300ppi or 250ppi at least. battery backup is not solely dependant on display resolution. It depends upon the battery chemistry and its charge holding capacity, chipset efficiency and the brightness setting of the display.

      For elongated battery backup always keep your brightness on minimum usable settings and set it to auto-brightness.
      Sunlight legibility depends not only on display but also on the display brightness.
      I’ll cover the display tech. in detail in the next post in #KYM series.

  • Jitendra Jangid says:

    Anand Sir,

    IF Any Mobile Not Have Auto Brightness Option By
    Default.Then,
    1. We Can Find AUTO BRIGHTNESS By Any ANDROID APPS ?
    2. This type Apps Work 100% Properly ?

    I think, Many Android Apps are Not Work Properly. (Equal to Scam).

    Example : Many USER Say Mostly Battery Saving Apps are Worst. etc

    Thank You for Reply & KYM Series.

    • Anand Karwa says:

      I’ll try some 3rd party apps from the play store and get back to you.

    • Anand Karwa says:

      I tried some free apps from the play store. These apps work on the readings they get from the light sensor and work pretty much in the way like sytem default auto-brightness settings.

      Most of the battery saving apps do basic stuff like turning off the data and wifi connection when not in use and dim/turn off the display after x amount of time etc. You can also do it yourself.
      Some advanced apps like BatteryGuru for Snapdragon chips can also stop the app refresh and turn on/off the wifi connection based on your location. If you are planning to buy a phone with Snapdragon chipset then this a must install app.

  • Jitendra Jangid says:

    Thank You Sir,
    Great Answer for US.

  • Jitendra Jangid says:

    Anand Sir,
    I think, for GET Auto Brightness.
    1. Mobile Must has Light Sensor ?
    2. IF mobile NOT has Light Sensor Then We can Find Auto Brightness By any way ?

    By The Way :
    1. IS Mobile Pre-installed APPS, BROWSER & FUNCTIONS that By Default in Mobile
    are Better Than Downloaded Android APPS, BROWSER & FUNCTIONS ?
    Example : Pre-installed Chrome Browser speed Fast OR Downloaded Chrome Fast?

    2. What are The Effects of Downloaded Android APPS, BROWSER & FUNCTIONS On
    Mobile ?
    3. How To Check Any ANDROID APPS About Proper Working, Virus Issue, Worst,
    Battery Issue Effect on Mobile etc.

    We want A POST on All About ANDROID APPS (Functionality, Accuracy and Effects) on Mobile.

    • Anand Karwa says:

      There are a few apps like Lux Auto Brightness which can use the camera input for adjusting the screen brightness.

      1. There is no way to tell if the pre-installed stuff is better/bad than the apps available on the play store. Chrome is Chrome no matter where you download it from.
      2. The downloaded app will obviously use some resources like RAM and CPU when you run it. If it is minimized throughout the day then it will eat up a large portion of battery charge.
      3. Use can use some anti-virus solution to scan the app.
      A word of advice: Do not download cracked/patched apps. They might have viruses/trojans embedded in them.

  • Jitendra Jangid says:

    Anand Sir,
    Thank You For Providing Good Knowledge.
    You Say : There are a few apps like Lux Auto Brightness which can use the
    camera input for adjusting the screen brightness.
    1. I Think, For Auto Brightness, Camera Must be Always On.
    OR It Possible when Camera Off ?
    2. We Can SCAN Android APPS By PC ?
    Computer Can Capable for SCAN to Android APPS and Find VIRUS etc ?
    Because Computer Running On Windows Operating System.
    While Android APPS Running ON Android Operating System.
    3. Please Suggest We,
    Which Anti Virus APPS are Great For Android Dual Sim Smartphones?
    4. All OR Mostly, Free APPS of Google Play Store are 100% Safe ?

    • Anand Karwa says:

      Please read the documentation of Lux Auto Brightness for more information.
      Anti-virus softwares are made to scan viruses. There are many anti-virus solutions available on the play store. You can try them as per your wish.
      There is no guarantee about safety of anything in this world. Google pulls down an apps as soon as they find out if its violates their terms but that takes some time. What if you downloaded what app before you knew that it has trojans embedded in it?
      Also no antivirus/anti-malware app provides 100% protection. After all the devs who create viruses also have to make their living. They just dont send the list/code of their newly generated virus to the security companies.
      In short, download stuff only from reputed websites and if you are short of heart then do not browse unsafe websites and keep your AV updated always.

  • Pankaj says:

    Sir,u must’ve heard about micromax yureka.It has a pixel density ~267ppi if i remember it right.Do u think it would be ok to view movies n operate it in sunlight.Actually,what determines whether a particular display would be good in bright sunlight or not. Before buying ?Thanx in advance

  • Ashwani says:

    Sir, if I change the display of my mobile to some local brand display, will it affect to my camera quality also.

  • sudip says:

    i thought buy microsoft lumia 640 xl , display 5.7″ but ppi 269 . then what problem face plezzz guy help me??? but camera 13 mp back, 5 front .plzzz give a suggestion?????

  • Zahirul says:

    Thanks for explaining sreen resolution and pixel density. I think pixel density should remain under 400 for any screen.

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