lundi 6 octobre 2014

Photography lesson

Photography lesson – Shutter Effects

 

You’ve probably seen those pictures of a race car or bike rider where the subject is in fairly sharp focus but the background is blurry with streaks denoting speed. Perhaps you’ve seen a waterfall that looks like flowing silk. Or you seen a picture with someone totally frozen in place during an athletic moment.
These are a result of creatively using the shutter on the camera. High shutter speeds, such as 1/500th, 1/1000th, 1/2000th or higher (remember these are fractions of a second) create a stopped motion.
Alternatively, slow shutter speeds such as 1/15th, 1/4, or even whole seconds, creates a sense of motion through blurring of some part of the picture.
One of the issues is quite often if the shutter speed is too slow, an image can be blurry from “motion blur” which can detract from an image if the effect isn’t intentional.
Exercise: This is best done on a lightly clouded day that isn’t too dark or too bright. Find a friend with a bicycle or who likes to run. Go to an open area and set up your position. Have your friend ride or run past you many many times. You’ll need to do lots of exposures to get the shots.
First set your shutter speed as high as you can for the light – hopefully around 1/500 to 1/2000 – with the aperture as open as you can set (i.e. ƒ1.8).
As your friend moves past you, keep him or her in the viewfinder, turning yourself at the waist to constantly point your camera at your friend. Take lots of pictures for several passes. This is known as “panning.” You might want to try a couple of passes without tripping the shutter and practicing keeping your friend in the viewfinder as he or she goes past you.
Now, set your shutter speed as low as you can – I’d suggest around 1/30, remembering to set the aperture as high as you can for the light. Repeat the above panning motion to keep your friend in the viewfinder. Take lots more pictures, remembering to keep turning yourself at the waist as your friend goes by.
PS – to keep your images acceptably sharp, the rule-of-thumb is to keep your shutter speed at least the same as your focal length – ie a 50 mm lens should be used with a shutter speed of 1/50 of a second or faster. However, I find with most digital cameras you want to add another 50 % to that – so you want to shoot at 1/80 or faster (The one third of a stop equivalent of 1/75).
For sharp pictures a tripod is a very handy tool to free up your choice of shutter speeds.
Alternatively, you can hand hold a camera to surprisingly extended times with good technique: place the bottom of the camera body in your left hand and support its weight with that hand, then tuck your left elbow basically into your lower left rib cage. Finally hold the viewfinder close to your eye and use your right hand to trigger the shutter and further stabilize the camera. Breath in and let your breath out slowly while squeezing the shutter.


Source: bestphotolessons.com

 

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