Practical Artistry: Light & Exposure for Digital Photographers

88 Selecting Shutter Speed

Shutter Speed and Camera Shake

Shutter Speed and Camera Shake

Camera shake is a shorthand expression used to de-

scribe the situation in which camera movement or vi-

b

ration causes a photo to be not acceptably sharp. If the

shutter speed is fast enough, camera shake becomes a

negligible issue.

Otherwise, addressing camera shake is essentially a

mechanical issue. What, or who, is going to keep the

camera steady in place?

Of course, sometimes you can create exciting motion

effects by moving, or even tossing, your camera during

an exposure, but generally camera motion is undesir-

a

ble (see page 101 for a discussion of when you might

want to move the camera during your exposure).

Human beings find it harder to stay really, really still

than they sometimes think. Just ask anyone taking an

introductory yoga or meditation class. How still you

can hold your camera begins to be a significant issue

at shutter speeds slower than 1/250 of a second. Take

a look at the table below to see when to use a tripod in

order to control camera motion.

Many exposures seem to lead to the middle territory

where you might be able to effectively hand-hold the

camera. In these situations, check your aperture to see

if you can let more light in and use a faster shutter speed

without losing necessary depth of field (Chapter 2).

A

lso, consider boosting the ISO (see Chapter 4) to use

a faster shutter speed.

Factors you should consider to see whether you can

successfully hand-hold a photo in the intermediate

zone of shutter speeds include whether you are using

image stabilization (see sidebar), and whether you are

using a wide angle or telephoto lens. The longer the fo

-

c

al length of the lens (and the more telephoto the lens

is), the more camera motion is a problem. If you are

taking a macro photo (close-ups show camera shake

more), this should tell you to probably use a tripod. A

final consideration is how still you think you can hold

your camera.

Some photographers have an exaggerated notion of

their ability to hand-hold at slow shutter speeds. (I’ve

heard this can even be a macho thing: real men don’t

let their camera wiggle, even at slow shutter speeds.)

Before assuming you can successfully hand-hold in

slow shutter speed situations, consider that profes

-

sio

nal photo editors generally advise against it. Exam-

in

e some test photos at extremely high magnification

on your computer, looking for shaded pixels next to

edges. These “extra” lines indicate subtle blurring that

will show if you make a large print of the photo.

Shutter Speed Range Tripod Required?

1/250 of a second and faster No (may be required with lens

longer than 300mm)

Between 1/125 and 1/30 of a second Maybe (see discussion below)

Slower than 1/30 of a second Yes

Hand-holding a Camera

To hold a camera as still as possible, first get yourself into a still

position. If possible, brace yourself against the wall, floor, or a

rock.

Next, brace your camera close against your body (usually your

forehead). Use both hands to hold the camera steady.

It’s a good idea to practice holding your camera steady before

you get into a situation where you need to be still. What

works best for you? Where can you grip the camera without

inadvertently pressing buttons?

Image Stabilization

A mechanism called variously image stabilization (IS) or

vibration reduction (VR) is built into many cameras (generally,

fixed-lens cameras) and lenses (intended for use on a dSLR).

Manufacturers claim that image stabilization gives you a two to

three f-stop exposure advantage, which translates to the ability

to use a shutter speed up to eight times slower than without IS.

There’s no doubt that you can get some hand-held shots with

image stabilization in marginal low light conditions that would

be impossible without the IS technology.

If you are taking advantage of IS to use slower shutter speeds,

you should be sure to make several shots of each photo

because the technology is erratic and doesn’t always work.

In my experience, for every three shots taken using image

stabilization at slow shutter speeds, one shot adjusts properly

for camera shake and the other two do not.

Image stabilization should always be turned off if you are

using a tripod because IS can actually make tripod shots less

steady (unless your camera or lens with IS has a mode specially

designed to be used with a tripod).