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Adjust luminance range
a.
Install Lumisphere.
b.
Hold meter at subject position, point Lumisphere toward camera and read needle
indication. With all lights turned on, adjust main light so that indication becomes 500
footcandles.
c.
Set
mark to 500 and read
value becomes 16 to indicate luminance range center point. If by experience the
required results can be obtained with a luminance range of 16 to 1, a maximum
luminance indication of 64 (center point 16 x 4 = 64) becomes the upper limit for
desired color reproduction. In this case, the minimum limit becomes 4 (center point 16
= 4 = 4). This means that attractive color reproduction cannot be obtained unless the
subject luminance distribution is within 4 ^- 64.
d.
Exchange Lumisphere for Lumigrid a nd check if there are any locations on the subject
brighter than 64 or dimmer than 4.
Stage 5
Determine correct exposure
Although above Stage 4b includes an exposure value measurement using the Lumisphere,
perform correct exposure measurement as a final check. With the illumination controlled as
described, this should accurately become F/5.6 1/50 sec. This 5 stage procedure allows full
control of all lighting elements.
Closeups
It is essential to increase the exposure value when the subject is closer to the camera than
10 times the camera focal distance. An example of this type of case is with a camera lens
focal distance to 50mm and a subject distance of 40cm. The reason for this is the
increased image magnification as the subject approaches the camera. When light from the
subject passes through the lens and becomes focused on the film, the following
relationship
exists
among
magnification.
31
film
plane
illumination,
ark indicated value. This
subject
brightness
and
image
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