arrow 804 and dot 802 are used to depict the x and y axes respectively fig8 b 8 c are graphs of the effect of tilt around the x and y axes in terms of tilt in arc minutes vs error in microns fig8 b shows the effect of tilt around the x axis versus error and image location along the y axis fig8 c shows the effect of tilt around the y axis versus error and image location along the x axis 0051 fig9 is a detailed side view of image ray traces according to a third exemplary embodiment of the present invention in fig9 the reference position of bonding tool 104 is shown as a reflected ray which travels from first position 914 on image plane 112 along first optical axis 114 shown in fig1 as direct image ray bundle 918 from first position 914 through lens element 902 note that in this exemplary embodiment lens element 902 has a relatively planar upper surface 904 and a convex lower surface 906 direct image ray bundle 922 continues along first optical axis 114 where it then passes through upper surface 904 of lens element 902 and in turn through convex surface 906 direct image ray bundle 922 is then reflected onto total.