What to know about SmartPhones
On this page we discuss everything you need to know about smartphones like: how smartphone screens are measured, what makes smartphone screens look very sharp and clear, fixed battery or changeable battery, internal memory or external memory, LCD IPS screen or Super AMOLED display screen, etc.
These are a list of smartphone topics covered. Clicking on any item on this list takes you directly down to that section on this page which is a bit long.
Smartphone screen size measurement
The smartphone screen size measurement can be given as an inch size or as a pixel size. For example a smartphone screen size can be 6 inch with pixel size of 720x1080 pixels. We will explain what smartphone screen size in inches mean and what the smart phone size in pixels mean
Smartphone screen size inches
Smartphone screen size in inches is the standard measurement of a phone's screen size. Many countries following the metric system, like Europe and India, mobile phone screen sizes are also specified in centimeters. To convert inches into Centimeters multiply the inch value by 2.54 (1 inch=2.54 cms or centimeters). To make screen size in inches from centimeters, divide by 2.54.
It should be remembered that phone screen sizes are always measured diagonally. The image of a smart phone screen here shows the smartphone screen dimensions in centimeters and inches measured diagonally from the top or bottom corner to the opposite corner at the bottom or top of the screen
The screen size of the smartphone image here, it is marked as 10.2 cms or 4 inches, the measurement from the bottom left corner to the top right corner. This is how the screen size of a mobile phone is measured.
Smartphone screen size in pixels
The smart phone screen is made up of thousands of tiny dots called pixels. Each of these tiny pixels can have a different colour controlled by the phones software. It is these different coloured pixels that make the picture on a phone screen. The small squares, in a mosquito-net like pattern in the picture here, are the pixels.
A 'Pixel" therefore is the smallest element which makes the picture on a screen and 'Pixel' is a short form of ‘Picture Element’. The more the number of pixels to make a mobile phone picture or writing, the sharper it becomes and makes the smartphone screen more easily readable.
The screen pixel size of smartphones is the number of pixels in the x-axis by the number of pixels in the y-axis. In the picture above of the smartphone screen, the screen size in pixels is 720x1080.
The number of pixels along the 'X' axis or horizontally is shown as 720 pixels and along the 'Y' axis or height is shown as 1080 pixels. This is the orientation of the 'X' and 'Y' axis when the phone is held vertically. When the phone is viewed held horizontally the wider width of phone screen becomes the X-axis and the shorter height of screen becomes the Y-axis, and the phone pixel size should read as 1080x720.
What is the resolution of a smartphone
The resolution of a smartphone can simply be explained as the pixel density of a phone screen. So smartphone screen resolution is a measure of how many pixels there are in a unit area, usually in a square inch. Thus smartphone screen resolution means 'how many Pixels per square inch' and is usually called 'Pixels Per Inch' or PPi. So a mobile phone with a higher PPi will be sharper and will have better readability on the mobile phone screen.
Best screen resolution for smartphone
The best screen resolution for smartphone is about 300 pixels per inch or 300 PPi. Going to a higher value than 400 PPi for phone screens is not that beneficial since there is a maximum PPi above which the human eye cannot make out the difference that well. No doubt, higher phone screen resolutions than 400 PPI do appear a little sharper in some cases, but it is not that much.
How to calculate PPI of a phone screen
The PPi of a smart phone screen can easily be calculated if you know the phone screen size and the phone pixel resolution by using the Pythagoras mathematical formula as shown in in the image here.
The image shows a 4 inch diagonal phone screen with screen resolution of 720x1080 pixels. This is how the width and height of the screen is worked out as follows:
We assign the value 'h' to the height and 'w' to be the width of the phone screen. The ratio of the height to width is 1080:720, and therefore the height will be 1.5w (1080/720=1.5). As shown in the calculation in the image, using the 4 inch diagonal screen size of the phone, we get the dimensions of the sides of the phone screen as width=2.63 inches and height as 3.945 inches. From this result the PPI of the phone is calculated as follows:
To find the PPi or pixels per inch of the phone screen, we have to divide the total number of pixels by the total area of the phone screen. Thus we must multiply 1080x720 and the result to be divided by the total area by multiplying 2.63x3.945 (the width and height of the phone screen we calculated above). The result will be 273.764 which will be rounded off by phone manufacturers to 275 PPi. Please note that instead of going to the trouble of multiplying to get total pixels and total area, it is easier to divide for example 1080 by the height 3.945 to get the same result. So just divide the pixel value of a side of a phone screen by the same side length in inches as shown in our image here.
Different types of smartphone screens
Two types of smartphone screens, the LCD (Liquid Crystal Display) and AMOLED (active-matrix organic light-emitting diode) are the topmost smartphone screens available today. The iPhone range of phones and Sony smartphones have LCD type screens and Samsung smart phones have AMOLED screens which they call Super AMOLED screens.
In LCD and AMOLED smartphone screens there are variations like IPS LCD screens and Super AMOLED screens. We present here a table comparing IPS LCD and Super AMOLED smartphone screens with their advantages and disadvantages:
|Parameter||Super AMOLED||IPS LCD|
|Picture Quality||Super AMOLED smartphones have better color, brightness, viewing angle and quick response time to fast moving action scenes||IPS LCD screens also have very good picture quality and only advanced instruments can differentiate between the picture quality of latest LCD and AMOLED smartphone screens|
|Picture Brightness||Super AMOLED screens produces is self lighting, meaning the pixels glow on their own without any back light. So the brightness is very good for indoors, but outdoors in the sunshine it is difficult to see an AMOLED phone screen clearly||IPS LCD works with a backlight and the backlight brightness can be adjusted according to the ambient light. LCD screens are very good indoors and is quite legible outdoors even in direct sunlight.|
|Thickness of Phone||AMOLED screen smartphones can be made extremely thin, since the AMOLED screen requires no backlight.||Due to the requirement of a backlight, LCD screen mobile phone tend to be slightly thicker than the AMOLED screen mobile phones|
Best smartphone camera megapixels
The common belief is that a phone camera with the higher MP (Megapixel) resolution is the better phone camera. This is not true at all, we explain why
A phone camera with 8MP may sometimes take better pictures than a camera with 20MP. When comparing phone cameras, the things to look for in a phone camera are the size of the sensor and the size of each pixel in the camera sensor. These camera sensor size is more important for a phone camera’s picture taking ability.
The megapixel count or MP of a camera is more important when you need to take large prints of a phone picture. On a TV or computer monitor, a cell phone picture taken with a 5MP camera will look just the same as one taken with a 20MP camera. The reasons for this are explained below.
How important is phone camera megapixels
Just by having more MP does not mean a better phone camera. Phone camera pictures are normally viewed on TVs, computer monitors, Tablets like iPads or on smartphone screens. HDTV picture with 1920x1080 pixels results in a HDTV picture of 2 million plus pixels or 2 Mega Pixels. The highest resolution TVs available in the market today is the 4K Ultra HDTV with 3840x2160 pixels, which if you multiply 3840x2160 gives a total of 8,294,400 pixels which is just a little over 8 megapixels.
A full HD TV has 1920x1080 pixels which gives just 2,073,600 pixels or 2 Megapixels. So the high megapixel smartphone camera pictures do not fit into a TV or a computer monitor and has to be compressed to show on a TV. Thus a smartphone camera picture taken with a 5MP camera will look just the same as one taken with a 20MP camera on a full HD TV but may look a little better on a 4K UHD TV. Again a 8MP smartphone camera picture and a 20MP picture will look the same on a 4K UHD TV since the maximum resolution of a 4K UHD TV is just 8 MP.
If on the other hand, if you need to print your smartphone camera pictures, then a high megapixel camera picture will beat a low MP picture. Another big advantage of having a high MP phone camera is that you can zoom the mobile cell images without too much loss of quality and this could be very useful when taking group photos, etc.
Smartphone Memory explained
Smartphones have mainly two types memory called RAM (Random Access Memory) and ROM (Read Only Memory). The use of RAM in mobile phone speeds up the functioning of all smartphones. How much RAM do I need for my phone? The short and simple answer is get as much as you can, because the more the RAM the faster the phone applications will execute. 2 GB of RAM will be fine for most applications, but if you do a lot of gaming then try to get the maximum possible, because to have fast responsive gaming experience you need a lot of RAM.
RAM or ‘Random Access Memory’ in a smartphone is a memory that is temporary, but is quickly accessible to the phone’s processor. The RAM is made up of millions of capacitors each capable of holding one ‘bit’ of information. That means in a RAM of 1 GB there should be at least 1,000,000,000 capacitors since a Giga byte = 1000 Mega bytes where each Mega byte is equal to a million bytes - in short a Giga byte or GB is a billion bytes.
The Capacitors in the RAM lose its charge as soon as it is powered off, so all of the Memory in a RAM can be removed and new memory loaded in the RAM in a fraction of a millisecond just by powering ‘off’ and ‘on’. Thus the memory of a RAM is very volatile and dynamic, and so RAM is referred to as having a ‘Volatile Memory’ and being dynamic, RAM is commonly called as ‘Dynamic Random Access Memory’ or ‘DRAM’.
The Read Only Memory (ROM) in Smartphones store the operating system of the phones like the Android and iOS software. Even though we call it a Read Only Memory: ROM it can be rewritten when the OS is updated. The reason why it is still called a 'Read Only" even though it can be rewritten is because only a system update can rewrite into those chips and the user cannot rewrite a ROM chip. These ROM chips for storage of the phone OS are usually only about 512 MB.
Smartphone internal Vs external memory
The main difference between a smartphone internal memory and external memory is that the phone internal memory is very fast in saving and retrieving info when compared to the external SD card memory. The external memory cards are usually slower to read and write than an internal memory chip. The fastest micro SD card available is the Class 10 micro SD card and is only able to write at a speed of 10 MB/second.
The external SD card memory operates much slower than the phone’s internal memory, so it is always best to have your apps in the phones internal memory. Also while taking photos and videos, it is better to use the phones internal memory and as soon as possible move or transfer the photos and Videos to the external microSD card. This way the camera performs better, and you can free up the internal memory whenever you get a chance.
Smartphone removable vs non removable battery
Both removable and non removable smartphone battery have their advantages and disadvantages. We will discuss the advantages and disadvantages of having a removable or a non removable battery in smartphones
The main advantage of having non removable batteries is that the phone can be built much thinner and more robust. The internals of the phone are sealed and protected from moisture and dust. There is no danger of the phone back covers and batteries coming out when the phone is accidentally dropped. Problems with smartphone non-removable battery are one, when the mobile cell phone freezes up or hangs and you cannot remove the battery to reboot the phone and two, in the event the battery needs to be replaced, it can only be done at the service centre of the phone manufacturer.
The main advantage of having smartphones with replaceable battery are that in case the phone hangs-up or freezes-up, you can simply remove and reinsert the battery to reboot the phone. The second major advantage of having a removable battery was that you could have a fully charged spare battery, which could be exchanged for the dead battery in the phone and have a ful charged phone which could work for hours.
Both of these advantages of having a removable battery in a smartphone is not there any more. Latest smartphones have keyboard shortcut buttons to reboot a hanged or frozen smartphone operating system. The advantage of being able to replace dead batteries with a fully charged batteries have been neutralised with modern day USB Power Banks which can recharge a dead or low battery smartphone on the run.
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