Aperture: A Visual Explanation

Today I’m going to talk about show you what changing your aperture does to your images.  Aperture controls how much light your lens is letting into your sensor (or film) when a picture is taken.  The numbers, known as f-stops, are numbers that refer to how wide your aperture is to let a certain amount of light hit your image sensor / film.  These stops are at f/1.4, f/2.0, f/2.8, f/4.0, f/5.6, f/8.0, f/11, f/16, f/22, f/32 and beyond.  The *LOWER* the f-stop, the *WIDER* your lens aperture is open and you’re letting *MORE* light through.   This allows for higher shutter speeds and is useful in situations where you may not have a lot of light; however, this also affects your depth of field.  Wider apertures have a shallower depth of field which throws more of your image out of focus.  Below you can get a visual idea of what happens when you start to close (stop down) your aperture when taking images.  All images were taken with a Nikon D600 and the AF 28-105mm f/3.5-4.5D lens @ ISO 100.


f/4.5, 1.0 sec shutter


f/5.6, 1.3 sec shutter


f/8, 2.5 sec shutter


f/11, 5.0 sec shutter


f/16, 8.0 sec shutter


f/22, 15.0 sec shutter


f/29, 20.0 sec shutter

As you can see visually, in the wider open apertures, the background is thrown more out of focus.  As I close the aperture down to f/29 then you can clearly read the titles of all of the DVDs in the background (obviously I don’t like Quentin Tarantino films at all…) as the depth of field has increased to the point where the titles are in focus.  Note that because of the lesser amount of light in, the shutter speed decreases in all of my sample pictures as well.  Each stop in aperture halves the amount of light coming into the camera so in theory the amount of time the shutter is open should double with it though automatic settings for shutter didn’t follow this rule exactly.

Visually, wide open apertures are more suitable for portraiture as it blows the background out of focus and prevents it from being distracting.  There may be some times when you’re shooting at f/8 to f/11 on a portrait if your background is part of the story or if you’re shooting a group and want everyone to be in focus.  Keeping in mind how this will affect your shots visually will expand your creative options when shooting!

Comments (1)

One Response to “Aperture: A Visual Explanation”

  1. Megan Coutcher says:

    Thank you so much for writing this and giving the actually examples in comparison. It is nice to see the exact same picture with the apeture changed to see the effect on the picture.

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