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Without TTL Metering
At close ranges (reproduction ratios greater than
1:10),
the amount of light reaching the film decreases
as the extension between the lens and film plane
increases. When non-TTL measurement is used for
this range, the result is underexposed photographs
unless compensation has been made for this decrease.
The table at the right gives the exposure factors (com-
pensation values) with exposure increase in f/stop for
non-TTL measurement at reproduction ratios greater
than 1:10. The table at the right is for use when
various extension equipment is attached*.
To calculate the necessary correction in shutter speed
rather than in aperture value, multiply a given ex-
posure factor by the exposure time. For instance,
if the normal exposure at a 1:4 reproduction ratio is
1/8 second, the correct shutter speed is 1/8 x 2 =
1/4 second.
* When you use the lens by itself or attach a teleconverter, such
as the
TC-301,
exposure compensation is not necessary.
Reproduction
ratio
1/10
1/8
1/7
1/6
1/5
1/4
1/3
1/2
1/1.8
1/1.6
1/1.4
1/1.2
1/1
1.2
1.4
1.6
1.8
2
Exposure
factor
1.4
1.5
1.5
1.6
1.8
2.0
2.5
3.4
3.8
4.3
4.9
5.8
7.3
9.2
1
1.4
13.8
165
I 19.4
Exposure
increase
in f/stops
1/2
1/2
2/3
2/3
1
1
1-1/3
1-2/3
2
2
2-1/3
2-1/2
3
3-1/3
3-1/2
3-2/3
4
4-1/3