Damien Demolder is a photographer, journalist and photographic equipment expert, speaker, judge and educator. He has worked in the photographic publishing industry since 1997, including 15 years at the world’s only weekly photo magazine, Amateur Photographer, where he was editor. Damien encourages moving out of the f/8 comfort zone and experimenting with less common apertures.
The apertures that photographers use are designed to suit specific purposes. Most lenses supply us with at least eight different full-stop aperture settings so that we can achieve at least eight different effects. However, a survey I did a while ago demonstrated that most photographers use only a few of those aperture settings and fail to make the most of what their lenses offer. We have a range of apertures for a reason, but most of us use the same few settings all the time. Search your archive by f/number to find out what you aren’t using and how your choices restrict the images you make.
Why we need eight apertures
I guess we all know that the main function of an aperture is to control the flow of light entering the camera – wide aperture for more light; small aperture for less. That’s just the basics though, as careful photographers consider also the quality produced when certain apertures are used. Physics dictates that the widest and smallest apertures are not those at which best image quality is produced.
The optimal settings for sharpness and resolution tend to be in the central area of the range – usually between f/4 and f/8. At these settings we generally achieve best overall sharpness, the most consistent resolution from the corners to the centre of the frame, and the least vignetting. For example, f/8 is deal for this shot where we need front to back sharpness so we can see both the man and the view behind him.
While those central apertures are indeed the best when it comes to reliable quality they aren’t very exciting. They are safe and sensible, but if you stick to them the whole time to ensure you are producing the best technical results you risk missing out on what most other people judge pictures on – creativity, drama and atmosphere.
We have eight apertures because each produces a different look. Depth-of-field control makes up a significant part of that difference and the ability of a wide aperture to force the viewer to look where you want them to look. We think of depth of field as ensuring everything from the foreground to the distance is sharp, but selective focusing with a wide aperture can ensure that only what you want people to see first is sharp. Selective focusing with a wide aperture gives you control of the viewer’s eyes and attention. A wide aperture might create soft edges and a bit of corner shading, but what it loses in quality it makes up for in the excitement of a focused subject against a dramatically blurred background.
Really wide apertures are brilliant for lifting a head-and-shoulders framed portrait out of a scene while creating a beautifully blurred background. Most of the time no one will care that f/1.2 isn’t the most technically perfect aperture. Here you can see just how much softer a wider aperture can make the backdrop:
Modern lenses are moving towards much better performance at the widest apertures and, while f/1.8 will never be as efficient as those safe middle settings, in some lenses and for some purposes it is often already good enough. Wide settings on a fixed focal length lens will produce much better quality then the same aperture on a zoom lens (with all other things being equal) so there is much less reason to avoid them.
Bring some sparkle, excitement and dynamism to your creative work by using a more daring aperture – not every time, but far more often than you might be doing at the moment.