The values of tacheometric constants depend on
1
Focal length of object glass interval between stadia hairs, horizontal distance from optical centre to the vertical axis of the tacheometry
2
Focal length of eye piece, interval between stadia hairs, horizontal distance from optical centre to the vertical axis of the tacheometry
3
Focal length of object glass§ interval between stadia hairs, vertical distance from optical centre to the horizontal axis of the tacheometry
4
Focal length of eye piece, interval between stadia hairs, vertical distance from optical centre to the vertical axis of the tacheometry