Conversely, if the collimation screw gets too tight, then loosen the other two
screws by the same amount.
7.
Once the star image is in the center of the field of view, check to see if the rings
are concentric. If the central obstruction is still skewed in the same direction,
then continue turning the screw(s) in the same direction. If you find that the ring
pattern
is skewed in a different direction, than simply repeat steps 2 through 6
as described
above for the new direction.
Perfect collimation will yield a star image very symmetrical just inside and outside of
focus. In addition, perfect collimation delivers the optimal optical performance
specifications that your telescope is built to achieve.
If seeing (i.e., air steadiness) is turbulent, collimation is difficult to judge. Wait until a
better night if it is turbulent or aim to a steadier part of the sky. A steadier part of the sky
is judged by steady versus twinkling stars.
NOTE: THE ADJUSTMENT SCREWS ON THE SECONDARY MIRROR
ARE VERY SENSITIVE. USUALLY A TENTH OF A TURN WILL
COMPLETELY CHANGE THE COLLIMATION OF THE SPOTTING
SCOPE. DO NOT FORCE THESE SCREWS IF THEY WILL NOT
TURN. IF TIGHTENING ONE SCREW IN THE DIRECTION YOU
NEED TO GO IS DIFFICULT, SIMPLY LOOSEN THE OTHER TWO
SCREWS BY EQUAL AMOUNTS TO BRING ABOUT THE SAME
CHANGE. DO NOT BE INTIMIDATED BY TOUCHING UP
COLLIMATION AS NEEDED TO ACHIEVE OPTIMAL HIGH-
RESOLUTION VIEWS. IT IS WORTH THE TROUBLE!!!!