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8/12/2019 Canon Skills - Aperture & Shutter Speed
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APERTURE &SHUTTER SPEEDHow aperture and shutter speed work in unison
Shutter speedexplained
As weve explained on the previous page, theaperture and shutter speed work togetherto determine how bright your exposures
will be. Shutter speeds are measured in seconds
(more commonly fractions of a second), but theavailable range increases in stops (although thiscan be set to jump in 1/2 or 1/3-stop steps). Eachstop doubles (or halves) the amount of time theshutter inside your EOS D-SLR remains open for.For example, a shutter speed of 1/60 sec lets inhalf the amount of light as 1/30 sec, a 1-stopdifference, while 1/15 sec is a 2-stop difference.
Fast and slow shutter speedsBut which shutter speed should you use? It depends on what yourephotographing. First, consider if your subject or part of your sceneis moving. If you use a slow shutter speed it will show a sense ofmovement (captured as motion blur), whereas if you use a fast shutterspeed it will freeze any movement in the frame. A slow (eg 1/5 sec or 10secs) shutter speed is often preferable if youre shooting a landscape
with water in and you want to capture the movement of the water. Butyoull need to set a fast shutter speed (eg 1/500 sec or 1/1000 sec) ifyou want to freeze any subjects in motion, such as sports or children.
1 / 4 0 0 SEC
0 .4 SEC
1 / 20 SEC
2 .5 SECS
This mechanism determines
how long the shutterremains open
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8/12/2019 Canon Skills - Aperture & Shutter Speed
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Optimum aperturesOptimum aperturesS hooting with your widest or narrowestaperture isnt always best. Your lens willhave an optimum range of apertures in themiddle that will produce sharp results fromthe centre to the edges, usually between f/8to f/11. Experiment to see which works bestfor your own lenses. If youre using awide-angle lens, you also dont always need
to shoot with your narrowest aperture forsharp landscape photos that are in focusfrom foreground to horizon. Stick to f/11 orf/16, then focus one third into the scene toensure shots are sharp from front to back.Only use f/22 or narrower if youre trying toget the slowest possible shutter speed.
W hen you change your lenss aperture setting, you alsoaffect depth of field (DoF). The DoF refers to the part ofyour scene thats acceptably sharp. Using a wide aperture (suchas f/5.6) will result in a shallow depth of field. This is why wideapertures are ideal for shooting portraits and wildlife as you canblur the backgrounds behind your subjects to really make themstand out in the scene. Using a narrower aperture (such as f/22)will result in a deeper depth of field. This is why narrow
apertures are perfect when shooting landscapes andcityscapes as you want to ensure your scene is acceptablysharp, right the way from the closest foreground objectsthrough to the background.
Depth of eld
f/ 22
f/ 5.6
f/ 8
f/ 4
TIP OF THE HOURGe t yoursel f
a tripod to use for slo w
s hu t ter speeds; o t her wise an y un wan ted
camera mo vemen t will transla te to
camera s ha ke resul ting in images
wi t h t he wrong kind o f blur!
Aperture explained W ID E
M ID -R A N G E N A R R O W
W hereas the shutter mechanism istucked away inside your camera,the aperture actually sits inside your lens.The aperture (or opening) of your lensvaries from wide to mid-range to narrow,measured as f/numbers (or f/stops), suchas f/4 (wide aperture) to f/8 (mid-range)to f/22 (narrow aperture). The wider theaperture the more light is let in to reach yourEOS sensor therefore brightening yourshots. The narrower the aperture the less
light is let in to reach your EOS sensor which therefore darkens your shots.
As a wide aperture lets in more light, thismeans youll need to use a faster shutterspeed for a standard exposure; this is whywide apertures are good for wildlife andsports eg f/5.6 at 1/500 sec. Conversely,a narrow aperture lets in less light, requiringa slower shutter speed for a standardexposure; which is why narrow aperturesare good for landscapes eg f/22 at 1 sec.
