01 October 2017

Aperture Demonstration for New Photographers

Aperture Demonstration: Canon EF 85mm f/1.8 USM Lens
Aperture Demonstration for New Photographers - With Canon EOS 6D / EF 85mm f/1.8 USM Lens

A brief aperture / background blur demonstration of 8 images captured at different apertures, but exactly the same depth of field between camera / subject and background distance.

Objective: To demonstrate what effect an aperture change will have on background blur when changing the aperture setting on the camera (with all other settings exactly the same).

Lens Apertures
Apertures selected from first to last image: f/1.8 / f/2.8 / f/4 / f 5.6 / f/8 / f/11 / f/16 / f22 (f/1.8 is the largest aperture (actual lens opening with f/22 the smallest aperture of the particular lens used). Read more on the inter-relationship between Aperture / ISO and Shutter Speed: Exposure Triangle>>

Note how the density of the background blur decrease from f/2.8 to f/22. The background blur changes will have very little effect on the focused subject (red telephone / money box).

Difference between Digital Noise and Background Blur View

When is this applicable? In almost all subjects we photograph - from portraits to wildlife to landscapes. For portraits you want to isolate the subject by using a larger aperture (smaller f/ number) i.e. f/2.8 - f/4, for wildlife; isolating animals from their immediate habitat at i.e. f/4 - f/5.6 and for landscapes where you want image sharpness across the frame with smaller apertures (higher f/ number) i.e. f/11 - f/16.

The quality and density of the blur will depend on type of lens used, focal length of the lens, distance to subject (and to background). Various other camera / environmental factors could also have an effect on the desired outcome.

Creative application will also have an effect on the background blur, i.e. long exposures or showing motion in some part(s) of an image. Another consideration is macro photography where you may want to capture a close-up flower with a very narrow depth of field relative to its background - where you may require an aperture between i.e. f/2.8 - f/11 depending on the required blur effect(s) across the frame.

Canon EOS Camera / Lens / Speedlite Flash - Other Settings Used

  • Canon EOS 6D / Canon EF 85mm f/1.8 USM lens / Canon Speedlite 430EX II
  • f/1.8 - f/22 / ISO 400 / 1/60s (85mm) Manual Focus (via Live View) Tripod

(Click To Enlarge / Slideshow)

Aperture f/1.8  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens  Aperture f/2.8  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens

Aperture f/4  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens  Aperture f/5.6  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens

Aperture f/8  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens  Aperture f/11  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens

Aperture f/16  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens  Aperture f./22  ISO 400 : Canon EOS 6D / EF 85mm f/1.8 USM Lens
Shooting Location: Milnerton Cape Town (Photographer: Vernon Chalmers)

More about the Exposure in Photography Exposure Triangle