What is the actual shooting distance of 17-85MM lens and how to convert it?

17-85MM lens means that the focal length of the lens is 17-85mm, and the equivalent focal length of the lens should be multiplied by the multiple of 1.6. What I want to emphasize here is that SLR lenses don't pay attention to the concept of shooting distance, because the shooting distance is from tens of centimeters to infinity. If you have to say the actual distance you can shoot, it is infinite.

Here is the concept of equivalent focal length. Because the size of the photosensitive elements of digital cameras varies from camera to camera, the imaging angles of lenses with the same focal length are different on digital cameras with different photosensitive elements. For example, a full-frame camera uses a lens with a focal length of 50mm, and the viewing angle is about 46 degrees, while the viewing angle of an APS-C camera is about 30 degrees, and the shooting angle is roughly the same as that of a lens with a focal length of 75mm on the negative of a full-frame camera. Therefore, it is impossible to compare the shooting range (imaging angle) of different cameras only by the real focal length of the lens.

But for users, what really matters is the shooting range (viewing angle) of the camera. Because we always use the lens focal length of a full-frame camera to define the shooting angle, we are also used to converting the imaging angles on photosensitive elements with different sizes into the lens focal length corresponding to the same imaging angle on a full-frame camera, and this converted focal length is the equivalent focal length.