Now you understand what aperture is, and how its affects the depth-of-field in a picture, let’s put it all into practice. It’s hugely important to develop a good understanding of this area because, after composition and accurate focus, the control of depth-of-field is what distinguishes real photographers from casual snappers. Creative photography is all about making choices based on the options available to you, and trust us – you really need to nail the aperture thing! Here’s quick exercise to help you master the whole thing…….
1. Start set the right mode.
Find (or set up) a subject and make sure there’s a reasonable distance of a couple of meters between it and the background. With your DSLR camera on a tripod, compose your shot and set Aperture Priority mode (A or Av) on your DSLR camera main “MASP” mode dial.
2. Use maximum aperture.
Dial in the maximum aperture value (the smallest f/number) by rotating the appropriate control on the DSLR camera body and, after switching to Manual Focus mode, focus on the subject in the foreground (MF will stop your AF wandering about). Take a shot, and your subject will be sharp but the background will be defocused – just like it appears in the viewfinder.
3. Use minimum aperture.
Now adjust your aperture control until it displays the smallest aperture (the highest f/number). If your DSLR camera has one, depress the depth-of-field preview button to check how the background has changed, and then take another shot. Your shutter speed will be much longer (hence the need for a tripod) and this time, the subject will still be sharp, and the background will be much more in focus.
4. Final step Experiment!
Because you have a whole range of apertures in between the extremes you’ve just used, your job as a photographer is to decide which one gives the best overall effect for your subject. Leave your DSLR camera set to Aperture Priority mode, experiment with different aperture settings, and get used to thinking about depth-of-field every time you take a picture. Enjoy!
Hyperfocal distancing
On DSLR lenses with distance markings (mainly prime lenses, nowadays) you can set your focus manually to generate the maximum possible depth-of-field. This technique is called hyperfocal distancing, and is really simple to do. In Aperture Priority mode, first set your aperture (say to f/22), and then compose your shot. With Manual Focus mode selected, turn the focus ring to align the infinity symbol with the furthest f/22 marker. Now you can read off the closest distance that’ll be in focus with the nearest f/22 marker. That’s it!