The aspect ratio is the ratio between width and height of an image.It is denoted as Aspect ratio = width / height.Simply,it is nothing more than the proportion between length and height of a photograph.
Standard And Multiplication Factor OF Aspect Ratio
Standard 4/3 format
The 4/3 is the standard par excellence of old cathode-ray tube TVs and non-panoramic PC screens.It has a multiplication factor of 1.334 . This kind of standard is sometimes used by compact cameras Its overturned version (3/4) is very useful for vertical photos.
It is 0.75 . This kind of format succeeds in giving a greater sense of balance to one’s vertical shots.The three-quarter format is the most suitable for vertical images.
This format is used as 35mm in use in most cameras. It has a multiplication factor of 1.5 and looks like a stable rectangle, well proportioned and excellent in almost all areas for horizontal photography.
It is a format used in photograph. It has a square shape and a multiplication factor of 1.The square is an unconventional format but still used in photography. It creates the idea of a “cut” shot. In square photography it highly recommended if it may positioned in the center of the shot.
The 16/9 has initially arrived in the world of cinema but subsequently became a standard also in photographic terms. It has a multiplication factor of 1.778,and is suitable for panoramic photography.It makes the image very similar to human vision. It is Absolutely not recommended for vertical images.
21/9, also known as Ultra Wide has a multiplication factor of 2.370. It is mainly used in the world of cinema.
Tips for optimal viewing Through Aspect Ratio
Display on monitor or TV
In this case the advice is to know the native resolution of the display. For example, suppose we have an HD Ready display then we will export the file pointing to a resolution of 1360 × 760; in Full HD with a resolution of 1920 × 1080; in 4K with a resolution of 4096 × 2048 and so on.
Display on mobile phones and tablets –
On smartphones it ranges from 480 × 640 on a mid-range display to a quadHD resolution of 1440 × 2560. On tablet instead we go from 1024 × 768 of a mid-range tablet to reach a maximum of 2560 × 1600 pixels of the high-end tablets.