Nikon Fisheye-NIKKOR 6mm f-2.8 - Manual (Page 13)

Be careful not to include in the picture unwanted objects such as the legs of
a tripod or the hands or feet of the photographer.
Besides the tripod socket on the bottom of the lens, the 6mm f/2.8 has
three other tripod sockets on the back so that the camera may be mounted
o n
a tripod facing upward.
Try not to let too much direct sunlight strike the lens, as this may cause
ghost images. One way to prevent this is to create an artificial “eclipse” by
using a 3-inch diameter shield attached to a thin rod or wire. Hold the shield
in front of the lens in such a way that it blocks out the direct rays of the
sun. The further you hold the shield from the lens, the less conspicuous it
will be in the resulting photograph.
BUILT-IN FILTERS- -D
A set of five filters is built into the rear end of the lens mount: skylight
(L1BC), medium yellow (Y48), deep yellow (Y52), orange (056) and red
(R60). These filters are mounted on a revolving turret so they can be moved
into place quickly one after another. Turn the knurled filter selector dial on
the side of the lens mount until the desired filter designation on the rim of
the dial clicks into place. The selector dial should not be set at an inter­
mediate position.
The skylight (LI BC) filter is used in either black-and-white or color photog­
raphy. The others are normally used to subdue the effect of certain colors
or to increase image contrast in black-and-white photography. Contrast
increases progressively from yellow to orange to red.
The table below shows the filter factors for film rated ASA/ISO 100. No
exposure compensation is necessary with the Nikon or Nikkormat cameras
which have thru-the-lens meters, since their built-in meters read only the
light passing through the lens and compensate automatically for loss of
light.
Type of film Type of filter
Filter factor
Daylight Tungsten light
Black-and-white and color L1BC 1 1
Black-and-white only
Y48 1.7 (2/3) 1.2 (1/3)
YS2 2 (1) 1.4 (1/2)
056 3.5 (1-5/6) 2 (1)
R60 8 (3) 5 (2-1/3)
} = Exposure corrections in f/stops
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