In Physics AS, it is important to know how to work out the resolution of a given image. The resolution is…
The size, in real life, of one pixel or real life length / no. of pixels
For this reason, it is usually measured in metres per pixel.
Let’s have an example and calculate the resolution of the following picture of the River Thames:
You will have to estimate the size of the image and therefore how many metres of ‘real life’ it is showing unless told. For the case of the River Thames, I have estimated the width of the given part of the river is 250 metres. On the picture, this is represented by 20 pixels (for that, I just added them up). Now, remembering the equation for working out the resolution of a image:
We have everything to work out the resolution of the above image of the Thames. 250 / 20 given us a resolution of 12.5 metres per pixel.
It is important to remeber that anything smaller than 12.5 metres you will not be able to see.