When internal coaxial illumination is combined with a standard zoom system, there are certain conditions that must be met to guarantee satisfactory performance, as defined by no dark corners at the image plane.

Because the last lens of the system acts as a condenser, the useable illuminated area on the object is restricted to approximately 11mm for the Zoom 6000 and 20.5mm for the 12X zoom.

To prevent dark corners, this area must be magnified to overlap the diagonal of an area sensor or length of a line scan.

Example: Zoom 6000, 1/2" format(8mm diagonal, 4.8mm vertical), customer input largest dimension = 10mm.

Required mag = 4.8 / 10 = .48X

Illumination = .48 * 11 = 5.28mm diameter lighted spot on an 8mm diagonal sensor – too small, therefore there will be dark corners – and the wizard will come up with a "no match".

Adjustments:

Need 8 / 11 or .72X to fill an 8mm diagonal

Can decrease the largest dimension to 4.8 / .72 = 6.67. This will fill the sensor, corner to corner, and the wizard will be happy.

Normally, with a zoom system, one locates at low mag and then "zooms up" to see detail. If you are willing to live with dark corners in the "locate" mode, then put in the acceptable largest dimension (6.67), and pick the solution where the lowest available mag allows you to reach .48X. As you "zoom up", the mag will increase and the dark corners will disappear.

Or you could go to the 12X zoom where the useable illuminated spot is 20.5mm. Here, the original .48X mag would produce a lighted spot on the sensor of .48 * 20.5 = 9.9mm, which is greater than the 8mm sensor diagonal, and the wizard, again, would be happy.

Precise Eye (coax)

While the Precise Eye lacks the zoom feature, it has the same 11mm useable illumination feature from the Zoom 6000. Therefore, the magnification, multiplied by 11mm, must equal or exceed the diagonal of the sensor (or length of the line scan).