User manual SIGMA 691

[. . . ] In order to get the maximum performance and enjoyment out of your Sigma lens, please read this instruction booklet thoroughly before you start to use the lens. Zooming Rotate the Rubber grip on the zoom ring to the desired position. FLASH PHOTOGRAPHY The camera's built-in flash will cause barrel shadow if used with this lens. For best results, please only use an external flash unit. DESCRIPTION OF THE PARTS (fig. 1) 1. [. . . ] Please refer to the instruction booklet for your camera body. On the lens mount surface, there are a number of couplers and electrical contacts. To avoid damaging the lens, be especially sure to place the lens with its front end down while changing the lens. remove the hood, then replace it on the lens in the reverse position. Two or more filters and/or SETTING THE EXPOSURE MODE The sigma lens functions automatically after mounting to your camera. Please, refer to the camera instruction book. special thicker filters, like a polarizing filter, may cause vignetting. When using a polarizing filter with AF camera, use the "circular" type. BASIC CARE AND STORAGE Avoid any shocks or exposure to extreme high or low temperatures or FOCUSING AND ZOOMING This lens features Sigma's built-in Hyper Sonic Motor (HSM). SIGMA AF and CANON AF For autofocus operation, set the focus mode switch on the lens to the "AF" position (fig. 2). If you wish to focus manually, set the focus mode switch on the lens to the "M" position. PENTAX AF and SONY For autofocus operation, set the camera to AF mode and set the focus mode switch on the lens to the "AF" position (fig. 2). If you wish to focus manually, set the focus mode switch on the lens to the "M" position. NIKON AF For autofocus operation, set the camera's focus mode to AF. If you wish to focus manually, set the camera's focus mode to "M" and adjust the focus by turning the focus ring. Please refer to camera's instruction manual for details on changing the to humidity. For extended storage, choose a cool and dry place, preferably with good ventilation. To avoid damage to the lens coating, keep away from mothballs or naphthalene gas. Do not use thinner, benzine or other organic cleaning agents to remove dirt or finger prints from the lens elements. [. . . ] When operating this lens in manual focus mode, it is recommended that correct focus be confirmed visually in the viewfinder rather than relying on the distance scale. This is due to possible focus shift resulting from extreme changes in temperature which cause various components in the lens to expand and contract. [. . . ]