Meade Instruments LX200 - Manual (Page 17)

Meade Instruments Corporation - Meade LX200 Instruction Manuals
directly into the eyepiece holder for straight-through observations. In this case, however, the image will
appear inverted and reversed left-for-right. (Note that the eyepiece holder is standard equipment on 7", 8",
and 10" models, but is an optional accessory for the 12" LX200). With the diagonal prism and mirror,
telescopic images appear correctly oriented up-and-down, but still reversed left-for-right. For terrestrial
applications, where a fully corrected image orientation is desired, both up-and-down and left-for-right, the
optional #928 45° Erect-Image Diagonal Prism should be ordered separately. Eyepieces and the diagonal
prism are held in their respective places on the 7", 8", and 10"telescopes by a moderate tightening of the
thumbscrews on the diagonal prism and eyepiece holder.
[ toc ] 4. Checking the Collimation of the Optics
The optical systems of all Meade Schmidt-Cassegrains are precisely collimated, or aligned, before leaving
the factory. However, if the telescope has received a severe jolt in shipment the optics can become de-
collimated, a situation which may result in serious image degradation. Recollimating the optics is, however,
a simple procedure which is easily performed by the telescope user. We urge all LX200 owners to
confirm the collimation of their telescope, and to recollimate the optics if necessary.
There is no collimation procedure required for the Meade 7" Maksutov-Cassegrain telescope. Factory
alignment assures optimal viewing accuracies.
[ toc ] 5. 12" Tube Swing-Through Limit
The length of the 12" LX200 optical tube prohibits the correcting plate end of the tube from swinging
through the fork arms as the tube will hit the mount. When the telescope is aligned, the software will stop
the telescope from moving into the mount. If the telescope is not aligned, there are also mechanical stops.
When in LAND or ALTAZ modes, this limit does not restrict any sections of the sky, since the limit is set at
45° from straight down. But when in the POLAR mode, some parts of the sky might be restricted,
depending on the latitude of the observing site.
Observing sites with latitudes higher than 45° will not have any restrictions. Latitudes below 45° will have
the southern horizon restricted somewhat. To determine the amount of sky not available, subtract the
latitude of the observing site from 45. This will give the number of degrees of southern horizon that the 12"
LX200 will not move to. For example, if the latitude of the observing site is 35°, then 10° (45-35) of
southern sky is unavailable for observations.
[ toc ] 6. 7" Tube Swing-Through Limit
The length of the 7" LX200 optical tube prohibits the correcting plate end of the tube from swinging through
the fork arms–the tube will hit the mount. When the telescope is aligned, the software will stop the
telescope from moving into the mount. If the telescope is not aligned, there are also mechanical stops and
some parts of the sky might be restricted if using a wedge, depending on the latitude of the observing site.
Observing sites with latitudes higher than 45° will not have any restrictions. Latitudes below 45° will have
the southern horizon somewhat restricted when using a wedge and polar aligning. To determine the
amount of sky not available, subtract the latitude of the observing site from 45, this will give the number of
degrees of the southern horizon that the 7" LX200 will not reach. For example, if the latitude of the
observing site is 35°, then 10° (45-35) of southern sky is unavailable for observations. No restrictions of
observable sky occur in the altaz mode of alignment and operation.
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