Almost every day there is new digicam announced, with the clear mission of providing more and more megapixels of resolution. But how many megapixels are useful for us? Is there an optimum? If so, is it avaliable yet? Let's start calculating!
Two things to take into consideration:
- The average human eye is only able to see two sperate points when they are seen under an agle larger than 1 arc minute (the 1/60th of a degree). Let's say the perfect human eye performes twice so good, by being able to separate two points under one half arc minute
- When watching pictures on a display that is 14' wide, the screen fills out the viewing angle of my eyes when watching from 33 cms. The viewing angle in this case is app. 56 degrees (from the top right corner to the bottom left)
How many pixels can I separate along the line from the top right corner to the bottom left? Approximately 56*60*2 = 6720. And what is the total resolution in this case? Come on, Pythagoras, let us know! In case of a picture ratio of 4:3, it is about 21 megapixels!!
So, the optimum is still not reached, there is still a reason why to increase resolution day by day.