The majority of professional photographers set their cameras to Aperture priority. They know that correct aperture combined with an appropriate focus point leads to stunning images.
So this note aims to increase your understanding of Aperture and depth of field and how it will affect your creativity.
The most general rule is choose the smalls aperture for landscape photography and the largest aperture for portraits. This is fundamentally what your camera might do if you set it to the mountain or face icon.
The term aperture is latin for hole. The larger the aperture the more critical your focus point becomes.
Apertures are expressed in fractions so the simplest way of remembering this is the smallest number equals the largest hole and the largest number equals the smallest hole.
Here is a series of images shot from the largest to the smallest aperture to show you the different effects. The focus point for all these images is the Granny.
Here you have a group of Lego people from Abraham Lincoln at the back to a businessman at the front. I have focused on the Granny and you will see that she is in focus but each character either side of her gets steadily out of focus. This effect is referred to as bokeh commonly pronounced as bowker. F2.4 is the largest aperture available for this lens.
So now the blonde mum and the skydiver are slowly coming into focus.
The blonde mum is nicely in focus now joining the Granny and slowly the hula girl is coming into focus.
More of our characters are coming into focus and you can now see the expressions on Abe and the businessman
Everything is slowly coming nicely into focus
A little bit clearer
So with f22. The smallest available aperture on this particular lens you see front to back sharpness with the businessman and Abe coming fully into focus.
Each lens in your bag will produce slightly different effects so test this yourselves and see what effects are possible.
Camera used for this is broadly irrelevant but for those of you that want to know:
Fuji XF 60mm lens