Meade Instruments LX200 - Manual (Page 90)

Meade Instruments Corporation - Meade LX200 Instruction Manuals
good performance. Take special care to read and understand this section well so that your LX200 will give
you the best optical performance.
Note: The 7" Maksutov-Cassegrain LX200 does not require collimation. For final optical tests, every Meade
Schmidt-Cassegrain is precisely collimated at the factory before shipment. Our company is well aware that
through shipment and normal handling, the optical alignment can be lost. The design of the optical support
system make the method of collimation easy to do. Even the uninitiated can make an alignment of the
optics to the same high precision that is performed in the Meade Instruments Optical Laboratories.
Fig. 26: Coillimation of the Optical System (1), (2), (3) Set screws for adjusting collimation.
To check the collimation of your LX200, center a bright star that is overhead, or use a reflected "hot spot"
of reflected sunlight from a chrome car bumper or a telephone pole insulator, with the supplied 26mm
eyepiece. To make a correct evaluation of the alignment it helps if the telescope has been allowed to either
cool down or warm up to the temperature where the instrument is set up. Temperature differences between
the optics and the outside air can cause distortion in the images.
With the star or hot spot centered, de-focus the image. You will notice that the out of focus star image looks
like a ring of light (the dark center of the ring is the shadow of the secondary mirror). Turn the focus knob
until the ring of light fills about 1/8th of the eyepiece field. Take note that if you keep cle-focusing the star
past about 1/8th of a field, that the ring will look perfectly concentric (even on all sides) even if the optics
are out of alignment, preventing you from seeing any misalignments. If the ring of light does not seem to be
even on all sides, or if the dark center seems to be offset in the in the ring of light, follow the method below:
To make collimation easy, the only adjustments possible on the 8", 10" or 12" LX200 come from the three
set screws (shown in Fig. 26) located at the edge of the outer surface of the secondary mirror housing.
DON'T FORCE THE 3 COLLIMATION SCREWS PAST THEIR NORMAL TRAVEL AND DO NOT
LOOSEN THEM ]VIORE THAN 2 FULL TURNS (COUNTER CLOCKWISE DIRECTION), OR THE
SECONDARY MIRROR MAY COME LOOSE FROM IT'S SUPPORT. YOU WILL FIND THAT THE
ADJUSTMENTS ARE VERY SENSITIVE: USUALLY, ONLY TURNING A COLLIMATION SCREW 1/2 A
TURN WILL GIVE DRAMATIC RESULTS.
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