Tamron 179D owner manual Checking DEPTH-OF-FIELD, Precautions in Shooting

Fig. 9	Fig. 10
Altering camera between vertical & horizon-	Detaching tripod-attaching base
tal positions	1. Loosen lock knob by rotating knob coun-
1. Loosen lock knob by rotating knob coun-	terclockwise.
terclockwise.	2. Pull out lock knob slightly.
2. Turn camera and lens so as position align-	3. Turn attaching ring upward while holding
ment marks meet each other.	locking knob.
3. Tighten lock knob by rotating knob clock-	* When detaching tripod-attaching base, hold
wise.	camera and lens securely, not to accidentally
	drop your valuable equipment.

CHECKING DEPTH-OF-FIELD

When you set the focus of a particular subject, there is an area in front of you and behind your subject that will also be in focus.

The depth-of-field table shows aperture values horizontally and ranges vertically. If, for example, the aperture is F8 and the shooting range is 5m (Focal length 400mm), the depth-of-field value is 4.96 (m)-5.04 (m) where F8 in the horizontal column and 5m in the vertical column intersect. If your camera has a preview mechanism, the depth-of-field effect can be confirmed in the viewfinder. For further details, see the instruction manual of your camera.

PRECAUTIONS IN SHOOTING

Tamron AF 28 - 105 (Model 179D) employs an internal Focusing (IF) system to achieve a remarkable 0.5m (1.6 feet) M.O.D. (Minimum Object Distance) at 105mm. Because of the characteristics of this optical design, the 105mm coverage, at the distances other than infini- ty, is wider than that coverage of lenses using an ordinary focusing system.

When the built-in flash on the camera is used, symptoms such as corner illumination fall-off or vignetting at the bottom part of the image may be observed, especially at the wider-angle range. This is due to the inherent limitation of the coverage of the built-in flash, and/or the relative position of the flash to the edge of the lens barrel, which causes shad- ows on the image. Accordingly, we recommend not using the built-in flash at wider-angle settings.