Continuing on from yesterday's post about aperture/f-stops, the photograph below is of a lake with four docks and the shoreline at the back. Unlike yesterday's photograph where only the water drips were in focus, for this shot I wanted everything in focus to create a graphic feel and flatness. It has more of a stacked look with an f-stop of f/16 than it would have had if I opened up to an f/9 or lower. And the crisp reflections in the water from front dock to the shoreline also influence the image looking flat.
The confusing part of f-stops is when the aperture is closed down it is the higher number (making everything in focus), while the lower numbers mean you are opening up (making only the object you focus on to be sharp). One would initially think that stopping down (f/16) would be the lower number and opening up (f/1.4) would be the higher number.
Just remember when you want everything in focus, change the f-stop to the higher numbers and when you only want one part of the image in focus, change the f-stop to a lower number.
And don't forget that when you change your f-stop you will have to adjust the shutter speed and/or the ISO number (aka film speed). All three of these settings are dependent on each other.