Letus Extreme and A1 tips?
 

I just got the Extreme last week and was curious if anyone out there had any tips on getting the best image.

I have the focus set at 5.2 feet and can see the ground glass "sand paper" appearance.

I am curious how far to zoom in to avoid vignetting. I notice that if I zoom in too far I get some serious color aberration.

NOISE: I am getting some very minor noise that I would like to avoid if possible.

Any and all tips are GREATLY appreciated. THANK YOU in advance.

-Doug D.