Basic Photography Course

When two flash units of equal intensity and at equal

distance from a subject illuminate the same area, the
exposure for one unit should be determined and then the
exposure should be halved because twice the intensity
of light is reflected from the subject.

OPEN FLASH

Flash pictures can be made without the camera

shutter and flash being synchronized, using a technique
called open flash. In the open-flash method, the camera
shutter is set at T or B, the shutter is opened, the flash
unit fired, and the shutter closed. The open-flash
technique is sometimes used when the level of light over
a large scene is very low or at night. This method of flash
photography allows the photographing of large scenes
that ordinarily are quite difficult to illuminate with
artificial light. The photographer can walk into a scene
with the flash unit and illuminate sections of the scene
or the entire scene. Any number of flashes can be used

during the exposure while the shutter remains open. A
silhouette of your body can be recorded if your body
gets between the flash and the camera.

To arrive at the exposure for an open-flash picture

using a manual flash, determine your flash-to-subject
distance and f/stop. Keep the distance equal to the
objects being illuminated when using manual flash; for
example, when the f/stop for the scene is f/5.6 based on
a flash-to-subject distance of 10-feet, every flash within
the scene should be 10 feet from that section of the scene
being illuminated, When an automatic flash is used, the
flash automatically shuts off when the proper amount of
light is reflected from the subject, providing the object
is within its distance range. When you are using a
manual flash, the exposure for open flash is determined
as previously discussed. This is true unless two or more
flash units with equal intensities are used at equal
distances, or two or more flashes from the same unit at
the same distance are used to illuminate the subject.

MULTIPLE EXPOSURES WITH
ELECTRONIC FLASH

Interesting multiple exposures can be made with

only one or two electronic flash units. Multiple exposure
pictures, besides being artistic and interesting, are often
used to study subject motion and position. This can be
accomplished by the following procedures:

1. Darken the room and position your subject

against a black background.

2. Allow enough background area for the number

of different exposures you intend to make. When you

are using a ground glass camera, mark off on the glass,
with grease pencil, the areas where the subject should

be for each different exposure. If not using a ground
glass camera, make a pencil sketch to help you position
the subject.

3. Set up the electronic flash lights so the minimum

amount of illumination falls on the background itself.

4. Turn off all room lights and make your first

exposure. Then, without advancing the film, move your
subject to the next position for the second exposure.
Repeat this procedure for each image you want to record
on the film.

PHOTOGRAPHING ACTION WITH
ELECTRONIC FLASH

Action of any kind, no matter how slight, can add

interest to most pictures. Each type of action requires a
different camera technique, but because of the short
duration of light from electronic flash, it is ideal for
recording any action ranging from a fleeting expression
to a sports triumph. Most electronic flash units have a
maximum flash duration (the length of time the light is
on) of about 1/800th second, and a minimum flash
duration as short as 1/20000th second, thus you can
"freeze" almost any action with the flash.

Indoors, where there is little existing light, you have

no problem because the electronic flash itself stops the
action; however, outdoors in daylight, you may
encounter ghost images. Ghost images can occur when
existing light and a slow shutter speed are used in
conjunction with electronic flash. A ghost image appears
as a blur when one image is recorded by the existing

light and a second sharp image by the electronic flash.

ELECTRONIC FLASH AT NIGHT

Flash photography, outdoors at night, can produce

very underexposed photographs if not taken properly.
Outdoors, flash does not carry very far; therefore, it can
be difficult to light objects from a distance; however,
this limited coverage also gives you great control.
Indoors, part of the output of a flash unit is reflected
from the ceiling and walls back to the subject. Rarely do
you find such reflective surfaces outside, so some light

is lost. To compensate for the light lost, you must open
up your aperture when photographing objects at any
distance. Because so much light is absorbed in these
large areas, it may not be uncommon to open up your
aperture two or three f/stops. Tests should be conducted
before shooting in large, indoor areas, such as
gymnasiums and hangar bays or outdoors at night, to

5-36

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 -> When two flash units of equal intensity and at equal distance from a subject illuminate the same area, the exposure for one unit should be determined and then the exposure should be halved because twice the intensity of light is reflected from the subject. OPEN FLASH Flash pictures can be made without the camera shutter and flash being synchronized, using a technique called open flash. In the open-flash method, the camera shutter is set at T or B, the shutter is opened, the flash unit fired, and the shutter closed. The open-flash technique is sometimes used when the level of light over a large scene is very low or at night. This method of flash photography allows the photographing of large scenes that ordinarily are quite difficult to illuminate with artificial light. The photographer can walk into a scene with the flash unit and illuminate sections of the scene or the entire scene. Any number of flashes can be used during the exposure while the shutter remains open. A silhouette of your body can be recorded if your body gets between the flash and the camera. To arrive at the exposure for an open-flash picture using a manual flash, determine your flash-to-subject distance and f/stop. Keep the distance equal to the objects being illuminated when using manual flash; for example, when the f/stop for the scene is f/5.6 based on a flash-to-subject distance of 10-feet, every flash within the scene should be 10 feet from that section of the scene being illuminated, When an automatic flash is used, the flash automatically shuts off when the proper amount of light is reflected from the subject, providing the object is within its distance range. When you are using a manual flash, the exposure for open flash is determined as previously discussed. This is true unless two or more flash units with equal intensities are used at equal distances, or two or more flashes from the same unit at the same distance are used to illuminate the subject. MULTIPLE EXPOSURES WITH ELECTRONIC FLASH Interesting multiple exposures can be made with only one or two electronic flash units. Multiple exposure pictures, besides being artistic and interesting, are often used to study subject motion and position. This can be accomplished by the following procedures: 1. Darken the room and position your subject against a black background. 2. Allow enough background area for the number of different exposures you intend to make. When you are using a ground glass camera, mark off on the glass, with grease pencil, the areas where the subject should be for each different exposure. If not using a ground glass camera, make a pencil sketch to help you position the subject. 3. Set up the electronic flash lights so the minimum amount of illumination falls on the background itself. 4. Turn off all room lights and make your first exposure. Then, without advancing the film, move your subject to the next position for the second exposure. Repeat this procedure for each image you want to record on the film. PHOTOGRAPHING ACTION WITH ELECTRONIC FLASH Action of any kind, no matter how slight, can add interest to most pictures. Each type of action requires a different camera technique, but because of the short duration of light from electronic flash, it is ideal for recording any action ranging from a fleeting expression to a sports triumph. Most electronic flash units have a maximum flash duration (the length of time the light is on) of about 1/800th second, and a minimum flash duration as short as 1/20000th second, thus you can "freeze" almost any action with the flash. Indoors, where there is little existing light, you have no problem because the electronic flash itself stops the action; however, outdoors in daylight, you may encounter ghost images. Ghost images can occur when existing light and a slow shutter speed are used in conjunction with electronic flash. A ghost image appears as a blur when one image is recorded by the existing light and a second sharp image by the electronic flash. ELECTRONIC FLASH AT NIGHT Flash photography, outdoors at night, can produce very underexposed photographs if not taken properly. Outdoors, flash does not carry very far; therefore, it can be difficult to light objects from a distance; however, this limited coverage also gives you great control. Indoors, part of the output of a flash unit is reflected from the ceiling and walls back to the subject. Rarely do you find such reflective surfaces outside, so some light is lost. To compensate for the light lost, you must open up your aperture when photographing objects at any distance. Because so much light is absorbed in these large areas, it may not be uncommon to open up your aperture two or three f/stops. Tests should be conducted before shooting in large, indoor areas, such as gymnasiums and hangar bays or outdoors at night, to 5-36 contents Basic Photography Course <- previous page next page ->	As an Amazon Associate I earn from qualifying purchases.
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