336
THE HASSELBLAD MANUAL
A larger unit, perhaps with a separate battery pack, is recommended when a large number of
fl ash pictures need to be made requiring more battery power.
The brightness of portable units is indicated in guide numbers, which are based on the
ISO setting that is used. Most companies quote the guide number for 100 ISO. The guide
number tells you at what distances the fl ash must be used for the various lens apertures and
can also tell you the maximum working distance. Divide the guide number by the distance.
For a guide number of 42 and an 8 foot distance, the aperture is 5.2 (
f
/5.6) the maximum
distance for
f
/2.8 is 15 feet. Guide numbers are given either in feet or in meters, so you must
work with the same units for the conversion. At any distance, the fl ash exposure is deter-
mined by the lens aperture (see Figure 18-2) regardless of the shutter speed.
Figure 18-1
Red eye. (1) Red eye is caused by the fl ash light being refl ected off the blood-fi lled
retina. (2). You can avoid this by placing the fl ash farther from the camera lens so that the
retina is shaded.
Figure 18-2
Flash exposure. Because the fl ash duration is likely shorter than the shutter speed,
exposure for fl ash is determined only by the aperture. Exposure for the fl ash is the same at
any shutter speed within the shutter’s synchronization capability.
Flash Operation
Portable fl ash units can be made for manual mode, automatic mode, dedicated mode, or a
combination of the three. Modern units, including those built into cameras offer dedicated
operation the most logical approach to fl ash photography.
Содержание Digital Camera
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Страница 2: ...The Hasselblad Manual ...
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Страница 165: ...Heidi Niemala Editorial photograph made with a 50mm lens in the basement of a pre Civil War building ...
Страница 166: ...Heidi Niemala Photographed for clothing designer with a 150mm lens ...
Страница 167: ...Heidi Niemala Editorial portrait with a 150mm lens ...
Страница 168: ...Heidi Niemala Photographed with a 50mm lens during a sand storm at White Sands ...
Страница 198: ...Jonathan Exley An attention creating image of mult time Indianapolis 500 winner Helio Castroneves ...
Страница 200: ...Jonathan Exley Lifestyle Designer Kathy Ireland Courtesy of kathyireland com ...
Страница 243: ...Marco Grob Singer Alvin Chea from theTake 6 band photographed with an HC 2 8 80mm lens on an H camera ...
Страница 244: ...Marco Grob A make up test shot made with an HC Macro 4 120mm lens on an H camera ...
Страница 247: ...Marco Grob The Stairs photographed in CapeTown for Glamour magazine with an HC 3 5 50mm lens on an H camera ...
Страница 312: ...Raya High jewlery photograph produced with an HC 3 2 150mm lens on an H camera Raya Photographer ...
Страница 381: ...366 THE HASSELBLAD MANUAL Chart A2 Area coverage in inches with single extension tubes for the 6 4 5 film format ...
Страница 383: ...368 THE HASSELBLAD MANUAL Chart A4 Area coverage in inches with single extension tables for the 33 1 44 2 sensor ...
Страница 385: ...370 THE HASSELBLAD MANUAL Chart A6 Area coverage in inches with combinations of tubes for the 6 4 5 film format ...
Страница 387: ...372 THE HASSELBLAD MANUAL Chart A8 Area coverage in inches with combinations of tables for the 33 1 44 2 sensor ...
Страница 397: ...Chart D Close up charts for 80 to 250mm Hasselblad lenses an 503 and other V system SLR cameras based on the film format ...
Страница 398: ...Close Up Photography on Film or Digital 383 ...
Страница 400: ...Jonathan Singer ...
Страница 401: ...Jonathan Singer ...
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