The secret is the porro prism adjustment setscrews hidden under the rubber armor close to the edge of the prism covers, as shown in the picture at the lower right. Use the screwdriver to carefully lift the rubber covering to reveal the setscrews. If you don’t stretch the rubber any more than necessary to reveal the setscrews, the rubber will snap back to original position when you are done. The setscrews may be rather difficult to move, and some downward pressure may be necessary to prevent stripping of the setscrew slot.
The setscrews move the image in the same direction as the screw. So when screwing the right setscrew inward (clockwise as viewed from above), the right image will move downward and also to the left. Unscrewing the right setscrew (couter-clockwise) moves the image upward and also to the right.
The left setscrew works in the same manner for the left image. Turning the setscrew clockwise moves the image in the left side down and to the right, counter-clockwise moves it up and to the left.
Typical minor miscollimation can usually be corrected by tightening just one setscrew. The key is to determine which side needs to move, and how much it needs to move. Make adjustments in very small increments, moving the setscrew as little as possible, and frequently checking progress by using the above visual tests. To correct for horizontal miscollimation, where excessive left-right difference exists between the left and right views, requires moving both setscrews. Move them both inward to push the images downward and toward each other. Make sure that you end up with perfect vertical alignment. A slight amount of left right movement between the two images is acceptable- in other words, the left image should be slightly to the left, and the right image, slightly to the right. Under no circumstances should the images cross over to the opposite direction- this will quickly cause a headache if viewing for any length of time.
Using the above techniques should allow you to obtain perfect collimation. The ultimate test is to view the night sky. Bright objects such as Jupiter should be well merged, with no double images. Perfect collimation will allow you to view for extended periods with no eyestrain or headaches.
