[. . . ] The meter coupling ridge and automatic diaphragm function together to permit full aperture exposure measurement. For non-AI type Nikon cameras, this lens is also fitted with a meter coupling shoe to permit the same operation. 10 MOUNTING THE LENS A Align the green aperture index © on the lens with the mounting index on the camera and insert the lens in the camera's bayonet mount. [. . . ] Note: The Teleconverters TC-301, TC-300, TC-14B and TC-14 cannot be used with this lens. VARIABLE APERTURE As the lens is zoomed out from 35mm to 70mm, the maximum aperture decreases approx. The two aperture indexes engraved on the chrome mounting ring indicate the difference: the green index is for use at the 35mm setting, while the brown one is for the 70mm setting. For intermediate focal length settings, align the aperture ring between the two indexes. The relationship between the focal length and the maximum aperture is shown in Diagram 1. When this zoom lens is used with cameras having through-lhe-lens 12 (TTL) metering, you need not worry about adjusting the aperture. However, when an independent exposure meter is used, slight adjustment is required, depending on the focal length setting. 3 E I = 35 50 *• Focal Length 70 FLASH PHOTOGRAPHY CARE Follow the instructions below when you take pictures with the speedlight unit because the maximum aperture ot this lens varies according to the focai length settings. €¢ In TTL automatic flash photography (when using the SB 18, SB 17, SB-16A/B, SB-15 or SB-20) No adjustment is required because the variation in aperture is automatically accounted for. However, when the flash-to-subject distance is close to either the near or far limit of the auto shooting range corresponding to your working aperture, the working aperture may need to be changed as you zoom in or out. • In non-TTL automatic or manual flash photography Slight adjustment is required. You can obtain the roughly correct exposure over all focal length settings by using the intermediate setting between the green and brown aperture indexes. For perfect exposure, adjust the coupling aperture according to Diagram 1. €¢ In combination with the speedlight SB-19 or SB-E mounted on the Nikon FG-20 or EM Make sure to set the shooting mode selector of the SB-19 or camera selector of a new-type SB-E at the "A" position. Otherwise, you can obtain the correct exposure only in the telephoto (70mm) setting, while your picture will be overexposed in the wideangle (35mm) setting due to the change of the maximum aperture of this lens. With negative-type film (for example, color negative film), this shift might not affect the picture itself, because it has a larger exposure latitude. [. . . ] If you use ether in cleaning the lens, a smudge sometimes appears on the surface of a multi-coated lens. If this happens, wipe it again with a cotton cloth moistened with alcohol. €¢ To clean the rear lens element without getting dust or any other material inside the lens, first turn the zooming ring to the 35mm focal length, then use a blower to remove dust or foreign objects; then wipe the surface of the rear lens element as described above. [. . . ]