Basic Photography Course

speed dial, the top part of the fraction (numerator) is not

indicated; for example, the shutter speeds 1/60, 1/125,

1/250, and so forth, are indicated as 60, 125, and 250.

When a camera with a focal-plane shutter is used

with an electronic flash, a predetermined shutter speed
must be set. At this speed the shutter and flash unit are
said to be in synchronization. When the flash and shutter

are synchronized, the shutter opening is wide open at the
same instant the flash fires. Usually, the slowest shutter
speed that syncs with a flash unit is indicated in red or
another off color or a lightning bolt symbol on the
shutter speed dial.

Function

The shutter serves two functions: controlling the

duration of the exposure and controlling subject
movement. These two functions are entirely separate
and distinct. You must determine the shutter speed
required for each condition. After determining the
shutter speed, you select the f/stop that provides the
correct exposure for the film speed and lighting
conditions. Normally, the duration of exposure is short
enough to prevent image blurring. You can always set
the shutter speed faster than the speed required to stop
image motion, but it should not be longer if you want
the image to be sharp; for example, when a shutter speed
of 1/125 is sufficient to stop subject motion, you can set
the shutter speed to 1/250 or faster, but not at 1/60 if you

want to stop the motion and produce a sharp image. Each
time you change the shutter speed, the diaphragm is
adjusted to produce a properly exposed image.

The correct sequence in determining the diaphragm

and shutter to produce a properly exposed negative is as

follows:

1. Compose and focus the image.

2. Stop down or open up the diaphragm until the

desired depth of field is achieved.

3. Select the shutter speed that will produce a

proper exposure when combined with your

aperture setting.

4. Determine whether the shutter speed is fast

enough to prevent image blurring.

5. If the selected shutter speed is too slow, reset it

to a faster speed and open up the aperture
accordingly.

When you increase the shutter speed, you

compromise and loose depth of field. Sometimes this is
the only way to produce a useable image. If you cannot

sacrifice some depth of field, there are several
alternative you can use: select a faster film, increase the
camera-to-subject distance, select a shorter focal length
lens, or change the camera angle, so the relative motion
of the subject to the camera is decreased.

Selecting the Shutter Speed

Knowing what shutter speed produces the right

effect for each picture is a skill you, as a Navy
Photographer's Mate, must acquire. Your pictures may
easily be spoiled by movement of either the camera or
the subject. In some instances, this movement can
actually improve your photographs.

Novice photographers often find it hard to believe

anything can happen during the brief instant the camera
shutter is open. This is not true; images can be blurred
when a shutter speed as fast as 1/250 of a second is used;
for example, when the camera or subject moves during
the fraction of a second the shutter is open, the image
may be recorded on the film as a blur. Blurring caused
by camera movement is noticeable in all images within
the photograph. When blurring is caused by subject
movement only, the background or some other part of
the scene will be sharp, and the subject blurred. Camera
movement blur can be corrected by supporting the
camera properly or by using a faster shutter speed.
Subject image movement can be reduced by using either
a faster shutter speed or by panning the subject.

As explained previously, when a faster shutter speed

is used, a wider aperture is required to produce correct
exposure. For this reason you should know what
minimum shutter speed is required to stop or freeze
different actions. You must take into account conditions
that exist when taking photographs. Strong winds,
vibrations, or a ship rolling from side to side must be
considered. There is a general rule you must follow for
determining shutter speed when handholding a camera.
The slowest shutter speed recommended to prevent
camera movement blur is to set the shutter speed so it
matches the focal length of the lens. When a shutter
speed does not exist for the focal length of the lens,
select the next highest shutter speed; for example, 1/30
second for a 25mm lens, 1/50 second for a 50mm lens,

1/125 second for a 100mm lens, 1/250 second for a

200mm lens, and so forth.

When a subject is in motion during exposure, the

image on the film also moves. Even though the duration
of exposure may only be 1/1000 of a second, the image
moves a small fraction of an inch during this time. The
problem you encounter is how much image movement

4-14

contents

Basic Photography Course

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DOFMaster for Windows On-line Depth of Field Calculator DOFMaster for Mobile Devices On-line Depth of Field Table Hyperfocal Distance Chart Articles FAQ Recommended Books Support Contact Links Home As an Amazon Associate I earn from qualifying purchases.	contents <- previous page next page -> speed dial, the top part of the fraction (numerator) is not indicated; for example, the shutter speeds 1/60, 1/125, 1/250, and so forth, are indicated as 60, 125, and 250. When a camera with a focal-plane shutter is used with an electronic flash, a predetermined shutter speed must be set. At this speed the shutter and flash unit are said to be in synchronization. When the flash and shutter are synchronized, the shutter opening is wide open at the same instant the flash fires. Usually, the slowest shutter speed that syncs with a flash unit is indicated in red or another off color or a lightning bolt symbol on the shutter speed dial. Function The shutter serves two functions: controlling the duration of the exposure and controlling subject movement. These two functions are entirely separate and distinct. You must determine the shutter speed required for each condition. After determining the shutter speed, you select the f/stop that provides the correct exposure for the film speed and lighting conditions. Normally, the duration of exposure is short enough to prevent image blurring. You can always set the shutter speed faster than the speed required to stop image motion, but it should not be longer if you want the image to be sharp; for example, when a shutter speed of 1/125 is sufficient to stop subject motion, you can set the shutter speed to 1/250 or faster, but not at 1/60 if you want to stop the motion and produce a sharp image. Each time you change the shutter speed, the diaphragm is adjusted to produce a properly exposed image. The correct sequence in determining the diaphragm and shutter to produce a properly exposed negative is as follows: 1. Compose and focus the image. 2. Stop down or open up the diaphragm until the desired depth of field is achieved. 3. Select the shutter speed that will produce a proper exposure when combined with your aperture setting. 4. Determine whether the shutter speed is fast enough to prevent image blurring. 5. If the selected shutter speed is too slow, reset it to a faster speed and open up the aperture accordingly. When you increase the shutter speed, you compromise and loose depth of field. Sometimes this is the only way to produce a useable image. If you cannot sacrifice some depth of field, there are several alternative you can use: select a faster film, increase the camera-to-subject distance, select a shorter focal length lens, or change the camera angle, so the relative motion of the subject to the camera is decreased. Selecting the Shutter Speed Knowing what shutter speed produces the right effect for each picture is a skill you, as a Navy Photographer's Mate, must acquire. Your pictures may easily be spoiled by movement of either the camera or the subject. In some instances, this movement can actually improve your photographs. Novice photographers often find it hard to believe anything can happen during the brief instant the camera shutter is open. This is not true; images can be blurred when a shutter speed as fast as 1/250 of a second is used; for example, when the camera or subject moves during the fraction of a second the shutter is open, the image may be recorded on the film as a blur. Blurring caused by camera movement is noticeable in all images within the photograph. When blurring is caused by subject movement only, the background or some other part of the scene will be sharp, and the subject blurred. Camera movement blur can be corrected by supporting the camera properly or by using a faster shutter speed. Subject image movement can be reduced by using either a faster shutter speed or by panning the subject. As explained previously, when a faster shutter speed is used, a wider aperture is required to produce correct exposure. For this reason you should know what minimum shutter speed is required to stop or freeze different actions. You must take into account conditions that exist when taking photographs. Strong winds, vibrations, or a ship rolling from side to side must be considered. There is a general rule you must follow for determining shutter speed when handholding a camera. The slowest shutter speed recommended to prevent camera movement blur is to set the shutter speed so it matches the focal length of the lens. When a shutter speed does not exist for the focal length of the lens, select the next highest shutter speed; for example, 1/30 second for a 25mm lens, 1/50 second for a 50mm lens, 1/125 second for a 100mm lens, 1/250 second for a 200mm lens, and so forth. When a subject is in motion during exposure, the image on the film also moves. Even though the duration of exposure may only be 1/1000 of a second, the image moves a small fraction of an inch during this time. The problem you encounter is how much image movement 4-14 contents Basic Photography Course <- previous page next page ->	As an Amazon Associate I earn from qualifying purchases.
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