Yes. For example if using a 200mm lens with a 1.4x TC 280mm is the basis for calculating the distance. Always use the actual focal length of the glass mounted to the camera. The crop factor does *not* come into play, however, because the sensor *crop* has *no* effect on the actual focal length (or optical properties) of the lens itself. But note that the depth of field *is* affected by the crop camera.
* Always use the *actual* focal length of the glass in figuring the distance.
* Do *not* use the crop factor in calculating the distance.
* Keep in mind that the crop factor *does* affect the depth of field
* When making AF adjustments within the camera, the lens alone *and* the lens/TC combination values are set and stored in the camera independently.