BUILT-IN Filters

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 on 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.

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 (L1BC) 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
	Y48	1.7(2/3)		1.2(1/3)
Black-and-white only	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