One of the three main settings you will adjust when taking any photograph, assuming you are shooting in either manual or aperture priority modes, will be your aperture value. When it comes to taking photographs of waves I personally would set the shutter speed first then the aperture, because my number 1 priority is to freeze the action (or blur).. then the depth of what is in focus.. then lastly the ISO to expose the image how I want it.
When it comes to choosing what aperture value to use I ask myself the following questions:
- What angle will I be shooting from? will I be shooting from side on or directly in front of the wave?
- How much of the image do I want in focus?
Photographing a wave/surfer from side on usually requires a larger depth of field (more depth in focus) than if I was to photograph a wave/surfer from front on.
When I started photographing in the surf using an 85mm prime lens, instead of the wide angle I started off with, I used the following site in order to understand what aperture value at what distance from the subject would give me the desired depth of field I was after. After a while of using various aperture values I got a feel for what aperture I need to get the image I was after.
As an example I’ve inserted two images below, one where my aim was to isolate a small portion of the wave using a large aperture, of f/2.5 (small depth of field), and the second image I wanted to keep in focus as much of the scene as possible, but using an aperture of f/10.