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استخدام الفلاش في التصوير القريب ..
الملحق ..
كتاب التصوير الفوتوغرافي المغلق
Using flash for close - ups
It is possible to take close - ups without using flash , which is a pity , since flash is an exciting tool . Electronic flash is balanced for use with daylight color films , so you can switch from using natural light to electronic flash on a single film .
Illuminating the background
A single lightweight electronic flash can illuminate a close - up outside , but since the intensity of a point light source rapidly falls off in inverse proportion to the square of the distance , a background just behind the subject will not be ade quately lit. To avoid the picture having a nocturnal appearance , use another flash to illuminate the background .
Determining the flash exposure
The formula used for calculating the correct exposure with flash does not apply when taking close - ups . You can make a direct reading using a flash meter or use a fiber optic macro flash sensor plugged into a National flash gun . Otherwise you can determine the correct exposure for a given film speed by keeping the flash in a fixed position and varying the aperture for each magnification .
Once you start moving the flash away from the camera , however , you will need to calculate the correct combination of flash - to - subject distance and aperture . Firstly , if the guide number ( GN ) for a given film speed is not known , it can be calculated with the following formula :
New film speed New GN = Quoted GNx Quoted film speed
If a flash has a GN of 50 for 100 ASA film , and you wish to use 25 ASA film
√25 New GN 50x = 50 × 0.5 = 25
By using the GN for the relevant film speed , you can calculate the flash - to subject distance ( in centimeters ) for different magnifications as follows :
GNX100 Flash - to - subject distance = f stopx ( magnification + 1 )
You will need to calculate the distance for different magnifications for each aperture , the most useful for gaining maximum depth of field being f16 and f22 .
Flash diffuser
A clip - on flash diffuser will give a soft light without harsh shadows .
Reflector
Some electronic flashes , such as the Vivitar , have optional reflector holders for bouncing the flash .
Twin flash bracket
This boomerang - shaped bracket allows a pair of small electronic flash guns to be mounted on either side of the camera . I reduce the output of one gun by covering it with a diffusing screen .
Single flash bracket
This Novoflex bracket allows a small electronic flash to be mounted anywhere . around the lens axis . The camera and flash can then be moved toward the subject as a single unit . When the flash is moved closer to the subject , this compensates for the light loss resulting from the increase in the amount of extension .
Macro flash
This unit consists of three flashes ( two only illustrated here ) , which can be used to illuminate a subject photographed with a macro lens or a standard lens with extension tubes . Two flashes are mounted independently of each other on adjustable arms clipped onto rings . These can be rotated around the lens axis , so the position of each flash can be quickly adjusted . A third flash can be mounted on a long arm to illuminate the background .
Multiblitz Minilite 200 system
This versatile . portable , studio flash system can be carried in a compact case Each basic electrically powered unit has a color corrected flash tube , a halogen modeling light , a built - in slave unit and a socket for a reflector umbrella ( right ) .
The interchangeable heads can be quickly fitted to the bayonet mount . When several Minilites are used , only one is connected to the camera ; the others are triggered by their built - in slave units .
Barn door attachment ▷ The angle of a direct light beam can be precisely controlled by using the clip - on barn door attachment ( right ) . Another clip - on accessory is a small diffuser screen ( not shown ) . A light box ( above ) provides a large diffusing light source for illuminating highly reflective subjects .
Snoot attachment This provides a narrow angled beam . The color can be changed by inserting a glass filter into the filter holder .
Vivitar 4600 modular system
This dedicated modular flash is the first 35mm system to have completely interchangeable heads . The standard flash head ( right ) has horizontal and vertical bounce , rotation through 270 ° and variable tilting positions ( below ) .
Bare bulb head
This is an electronic substitute for an incandescent light bulb .
Zoom head
The power zoom head has four settings for use with different focal length . lenses . When it is in the 50mm position , it gives extra power and so boosts the guide number ( below ) . A power pistol ( not shown ) supports the flash away from the camera and shortens the flash . recycling time .
Open flash
If you have only a single flash you can use it to paint light on a stationary subject using the open flash technique . You will need to work in a dimly lit room , using a slow - speed film and a small aper ture . Position the flash on a stand and release the shutter on the B setting using a locking cable release to keep the shutter open . Hold a black card in front of the lens while repositioning the flash . Re move the card and fire the flash manually , and finally close the shutter .
Remote triggering
Firing the camera by using a remote trigger may be the only way you will get a photograph of a timid animal in the wild . Most simply this can be done using a long air release and setting up the camera at a site which has been baited . The only way to ensure the subject is sharply focused is to set up a pair of crossed light beam triggers and to prefocus the camera at the point where they intersect . When working at night , use a red or an infra - red light beam instead of normal white light , so that nocturnal animals cannot detect it . Use a camera with a motorized body to avoid unnecessary disturbance when recocking the shutter by hand .
Slave units
Light - sensitive slave units are used to fire cordless flash guns which are not attached to the camera . The light emitted from the main flash , which is connected to the camera , is instantaneously detected by each slave unit , which triggers off its own flash . A slave unit may be fitted with a suction disk for attachment to a flash ( left ) , a flash shoe ( below left ) or a tripod bush thread ( not shown ) . The synchro cord from the flash must be plugged into it . Optical slave units cannot be triggered by sunlight or tungsten light .
Hot shoe to flash cable adapter
If your camera has a hot shoe connection for firing a flash , and no separate flash synchronization socket . you will not be able to use a flash remote from the camera without this adapter . After it has been inserted into the camera hot shoe , a flash extension lead is plugged into the side . A flash can then be moved anywhere around the lens axis . If you wish use multiple flashes , either insert a multiple flash connector into the adapter , or use slave units on the additional flash guns .
Multiple flash connectors
If you do not have slave units for firing several flash units at once , there is a cheaper alternative - a multiple flash connector . Plug this into the camera flash synchronization socket and attach an extension lead from each flash to the connector . Above from left to right are double and quadruple connectors .
Automatic synchro - cord
This cord can be used to fire a " dedicated " automatic flash remote from the camera . One end is inserted into the camera hot shoe , the other into a flash shoe on a bracket or a light stand , for connection to a flash .
Flash ball and socket head
This head has a inch tripod thread at the base . and a flash shoe at the top . They allow quick adjustment of a flash remote from the camera .
Minolta Flash Meter III
This versatile meter gives precise readings of incident or reflected ambient light or tungsten light , a combination of both , or of pulsed light . The booster II accessory ( above ) will read directly off the focusing screen or the film plane . Here the meter is connected to the eyepiece of an SLR camera with bellows , where it can make TTL readings of flash exposures .
الملحق ..
كتاب التصوير الفوتوغرافي المغلق
Using flash for close - ups
It is possible to take close - ups without using flash , which is a pity , since flash is an exciting tool . Electronic flash is balanced for use with daylight color films , so you can switch from using natural light to electronic flash on a single film .
Illuminating the background
A single lightweight electronic flash can illuminate a close - up outside , but since the intensity of a point light source rapidly falls off in inverse proportion to the square of the distance , a background just behind the subject will not be ade quately lit. To avoid the picture having a nocturnal appearance , use another flash to illuminate the background .
Determining the flash exposure
The formula used for calculating the correct exposure with flash does not apply when taking close - ups . You can make a direct reading using a flash meter or use a fiber optic macro flash sensor plugged into a National flash gun . Otherwise you can determine the correct exposure for a given film speed by keeping the flash in a fixed position and varying the aperture for each magnification .
Once you start moving the flash away from the camera , however , you will need to calculate the correct combination of flash - to - subject distance and aperture . Firstly , if the guide number ( GN ) for a given film speed is not known , it can be calculated with the following formula :
New film speed New GN = Quoted GNx Quoted film speed
If a flash has a GN of 50 for 100 ASA film , and you wish to use 25 ASA film
√25 New GN 50x = 50 × 0.5 = 25
By using the GN for the relevant film speed , you can calculate the flash - to subject distance ( in centimeters ) for different magnifications as follows :
GNX100 Flash - to - subject distance = f stopx ( magnification + 1 )
You will need to calculate the distance for different magnifications for each aperture , the most useful for gaining maximum depth of field being f16 and f22 .
Flash diffuser
A clip - on flash diffuser will give a soft light without harsh shadows .
Reflector
Some electronic flashes , such as the Vivitar , have optional reflector holders for bouncing the flash .
Twin flash bracket
This boomerang - shaped bracket allows a pair of small electronic flash guns to be mounted on either side of the camera . I reduce the output of one gun by covering it with a diffusing screen .
Single flash bracket
This Novoflex bracket allows a small electronic flash to be mounted anywhere . around the lens axis . The camera and flash can then be moved toward the subject as a single unit . When the flash is moved closer to the subject , this compensates for the light loss resulting from the increase in the amount of extension .
Macro flash
This unit consists of three flashes ( two only illustrated here ) , which can be used to illuminate a subject photographed with a macro lens or a standard lens with extension tubes . Two flashes are mounted independently of each other on adjustable arms clipped onto rings . These can be rotated around the lens axis , so the position of each flash can be quickly adjusted . A third flash can be mounted on a long arm to illuminate the background .
Multiblitz Minilite 200 system
This versatile . portable , studio flash system can be carried in a compact case Each basic electrically powered unit has a color corrected flash tube , a halogen modeling light , a built - in slave unit and a socket for a reflector umbrella ( right ) .
The interchangeable heads can be quickly fitted to the bayonet mount . When several Minilites are used , only one is connected to the camera ; the others are triggered by their built - in slave units .
Barn door attachment ▷ The angle of a direct light beam can be precisely controlled by using the clip - on barn door attachment ( right ) . Another clip - on accessory is a small diffuser screen ( not shown ) . A light box ( above ) provides a large diffusing light source for illuminating highly reflective subjects .
Snoot attachment This provides a narrow angled beam . The color can be changed by inserting a glass filter into the filter holder .
Vivitar 4600 modular system
This dedicated modular flash is the first 35mm system to have completely interchangeable heads . The standard flash head ( right ) has horizontal and vertical bounce , rotation through 270 ° and variable tilting positions ( below ) .
Bare bulb head
This is an electronic substitute for an incandescent light bulb .
Zoom head
The power zoom head has four settings for use with different focal length . lenses . When it is in the 50mm position , it gives extra power and so boosts the guide number ( below ) . A power pistol ( not shown ) supports the flash away from the camera and shortens the flash . recycling time .
Open flash
If you have only a single flash you can use it to paint light on a stationary subject using the open flash technique . You will need to work in a dimly lit room , using a slow - speed film and a small aper ture . Position the flash on a stand and release the shutter on the B setting using a locking cable release to keep the shutter open . Hold a black card in front of the lens while repositioning the flash . Re move the card and fire the flash manually , and finally close the shutter .
Remote triggering
Firing the camera by using a remote trigger may be the only way you will get a photograph of a timid animal in the wild . Most simply this can be done using a long air release and setting up the camera at a site which has been baited . The only way to ensure the subject is sharply focused is to set up a pair of crossed light beam triggers and to prefocus the camera at the point where they intersect . When working at night , use a red or an infra - red light beam instead of normal white light , so that nocturnal animals cannot detect it . Use a camera with a motorized body to avoid unnecessary disturbance when recocking the shutter by hand .
Slave units
Light - sensitive slave units are used to fire cordless flash guns which are not attached to the camera . The light emitted from the main flash , which is connected to the camera , is instantaneously detected by each slave unit , which triggers off its own flash . A slave unit may be fitted with a suction disk for attachment to a flash ( left ) , a flash shoe ( below left ) or a tripod bush thread ( not shown ) . The synchro cord from the flash must be plugged into it . Optical slave units cannot be triggered by sunlight or tungsten light .
Hot shoe to flash cable adapter
If your camera has a hot shoe connection for firing a flash , and no separate flash synchronization socket . you will not be able to use a flash remote from the camera without this adapter . After it has been inserted into the camera hot shoe , a flash extension lead is plugged into the side . A flash can then be moved anywhere around the lens axis . If you wish use multiple flashes , either insert a multiple flash connector into the adapter , or use slave units on the additional flash guns .
Multiple flash connectors
If you do not have slave units for firing several flash units at once , there is a cheaper alternative - a multiple flash connector . Plug this into the camera flash synchronization socket and attach an extension lead from each flash to the connector . Above from left to right are double and quadruple connectors .
Automatic synchro - cord
This cord can be used to fire a " dedicated " automatic flash remote from the camera . One end is inserted into the camera hot shoe , the other into a flash shoe on a bracket or a light stand , for connection to a flash .
Flash ball and socket head
This head has a inch tripod thread at the base . and a flash shoe at the top . They allow quick adjustment of a flash remote from the camera .
Minolta Flash Meter III
This versatile meter gives precise readings of incident or reflected ambient light or tungsten light , a combination of both , or of pulsed light . The booster II accessory ( above ) will read directly off the focusing screen or the film plane . Here the meter is connected to the eyepiece of an SLR camera with bellows , where it can make TTL readings of flash exposures .
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