F-Theta Lens and HeNe Issues

[rltw]

I'm using Linos F-Theta lens, some with the PG coating, some without. The laser source is 1064nm (Fiber) and the lenses are appropriate for the wavelength. The issue is when using the guide laser, which - although it's not really - we refer to as the HeNe, as the mark moves closer to the boundry of the marking window, the guide laser traces the mark closer in both the X and Y axis to the center. That is to say... If I am marking a 25mm square box near the top left, or any corner, of the marking window, when I test the mark w/ the galvos and the HeNe, the mark is traced closer in both directions to center. Now, without any changes, the 1064nm laser is fired the actual ablated mark is further away in both directions from center.

I believe, because of very limited, very simple testing that the reason for this is that the Linos F-Theta lens is treating the visible HeNe light different than the IR 104nm light.

This is trouble for visual setup, etc.

Any ideas or suggestions would be greatly appreciated...