Pentax SMC -FA manual 200, Infrared Index of the Zoom Lens

Infrared Index of the Zoom Lens

When taking infrared photographs with the zoom lens, compensation in focus is neces- sary depending upon the focal length. The distance scale of the zoom lens has infrared indexes for each focal length.

Compensate for the focus according to the focal length in use (see page 9.).

	50		20	ft
	15		7	m
70	200	70
			200

With lenses having indexes only for the longest and shortest focal length, such as FA Zoom 70-200mm, obtain the compensation value for intermediate focal length by using the scale as a guide.

28 -105

ft	15 8	5	3	2	1.6
m	∞�	2	1.2	0.7	0.5
	5 3

The red line on the lens barrel of the FA28- 105mm f/4-5.6 (IF) is the infrared index line. Compensate for focus according to the focal length in use. See more details on page 9.

•The following lenses have no infrared index line.

FA Zoom 28-90mm f/3.5-5.6

FA Zoom 28-200mm f/3.8-5.6

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