Canon QL FT - Page 13

• Time exposure is also possible by using the
lockable cable release.
•
The" X" index is used for synchronizing an
electronic flash unit such as the Canon Speed-
lite . Although the shutter speed at "X" is
1/ 60 sec., it is equivalent to a very short ex-
posure time during the flash of the flash unit .
Aperture
Incoming light and depth-of-field are adjusted
by turning the pre-set aperture ring to the
desired f/ stop.
• As the f/ stop value gets larger, the amount
of light reaching the film plane becomes cor -
respondingly less. For each f/ stop the light is
reduced
one· half. Accordingly , when the aper -
ture is increased by one f/ stop , the e xposur e
is
doubled, and when it is increased by two
f/ stops the exposure is quadrupled .
• Certain lenses,
have no relation to the
li ghtness being halved between the maximum
and the next f/ stops on the pre-set aperture
ring.
• The pre·set aperture ring can also be s et
between two f/ stops .
• The ratio between the aperture and the
amount of exposure , using f/ 2 as the basis,
is as
follows :
Lens Aperture
1.2 1.4 1.8 2 2.8 3.5 4 5.6 8
11 16 22
Ex posure Ratio
3 2 1. 25 1 112 113 11 4 1/8
11 16 1/ 32 1/64
11 128
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