I just picked up a Swiss Wild optical rangefinder. needs to be calibrated. I have found the adjustment screw on the left side of the rangefinder. when I adjust it, the image adjusts vertically. however, I can't seem to get the two images to be horizontally mirror images (calibrating on the moon). the only way I can get two images perfect is to adjust the right rangefinding knob. then it says about 3500 meters. if put at infinity the images are off a little bit horizontally. is there another adjustment point?