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Review of the LXD 55 10" Schmidt Newtonian The OTA and GEM both arrived in excellent condition. No speckles on the mirror or blemishes on the exterior surfaces, their QC may have improved recently. However, a star test revealed that additional collimation was necessary on the secondary mirror.
THE MOUNT AND TRIPOD The mount and tripod can handle the weight of that big 30lb OTA just fine. However, the entire setup should be balanced very well in both RA and DEC to avoid motor strain. I have spent some time analyzing the motor construction and its parts and once again it was surprisingly well built for the price. Additionally, the Autostar will not perform if unbalanced and warns of "overloading". The balancing on this scope needs to be very accurate to perform well, but once completed the telescope move easily in any direction. The motor drives should last many years if treated carefully. The real bonus with this package is Autostar, which worked as advertised and becomes quite easy to use after a few hours. All objects were centered nicely in a 26mm eyepiece. Attention needs to be paid to accurate leveling, time and location data and the drives should be "trained" and "calibrated" every time the batteries are changed. Calibration tests should also be done as the battery life expends. This will ensure a higher degree of pointing accuracy. A note on the batteries, I've been using the telescope under 3 degrees Celsius, battery drain and performance worsen significantly. At this temperature ordinary batteries are flat or useless in 8 hours. Using alkalines at these temperatures will give you about double the useful battery life. Meades claim of 40hours battery life with 8 D size batteries must have special conditions. If you live in cold climates consider the optional 115v AC home outlet cord or a deep cycle 12v battery. The "heavy-duty" aluminum tripod, as it is described by Meade, is adequate for most "observing" situations. Using rubber suppression pads, the dampening down time with a 26mm EP is under 1 second in the GOTO slewing mode, where the motors step down as the object centres. In the max (9) speed manual mode dampening is 2 to 3 seconds. It is because of this acceptable performance with my observing program that I haven't replaced the tripod or made any modifications. However, I would suggest the LXD 55 series mount and tripod is best suited for low to medium power "observing" situations. Eyepieces under 10mm have a dampening down time of 3 to 4 seconds, worse the constant shaking while focusing. It is hard to focus accurately at higher powers, but an electric focuser would partially solve this problem.
OPTICS These Schmidt Newtonians are marketed as fast optics with wide field
of view. They certainly are, but it means the scopes lend themselves
towards favoring situations where these characterics are desirable.
For example medium to low power deepsky observing, comet hunting and
fast astrophotograhy. And away from high magnification situations like
detailed study of the moon and planets and high magnification Astrophotography.
Besides the mount and tripod wont support this kind of work without
modifications. Before testing for optical aberrations I made sure that the collimation was close to perfect using the "star test". With these fast Schmidt Newtonians if the collimation is not superb you'll get noticeable astigmatism and coma. This can suggest that the optics are not very good, but in fact it may only be your secondary or primary mirror is out of alignment. My first test was for astigmatism using the star test method. I could not detect any on either side of best focus. Next I looked for any spherical aberrations, which shows the star as a blurred disk instead of a sharp point. The stars were very sharp all the way to the edge of a 26mm EP. However, the stars do have a small star-crossed appearance, this is particularly noticeable with bright stars in astro-photographers. This aberration is the result of the three mirror clamps holding the primary mirror. For myself this is not a problem as I am primarily an observer more than an astrophotographer. There is some coma towards the edge of the field of view. With a low to medium eyepiece this isn't noticeable unless your slightly out of focus. More noticeable with very high magnification (6mm) if your focusing on stars at the center of the EP. To some extent this is to be expected in a fast f4 Schmidt Newtonian like the Meade LXD 55 10". One area that I was very impressed with was the complete lack of any chromatic errors. The correcting plate with UHTC coatings is very purple in color and I was concerned about color errors in some wave lengths. This was misplaced, star colors across the spectrum are superb and accurate.
IN SUMMARY However, it is noticeably weaker with very high magnification work, both optically and mechanically, especially prolonged detailed study of bright planets. This is not recommended because of the constant shaking while focusing and vibration transfer from the tripod. An electric focus would be essential for this kind of observing long term. Additionally, Astrophotography may prove difficult and disappointing at high power. The LXD55 10" SN would not be recommended as a first or entry level telescope. Its sensitivity to incorrect balancing and collimation could be frustrating to many new amateurs. Additionally, image problems with very high power could prove disappointing to some new astronomers. Nevertheless, in the final analysis the Meade LXD 55 10" Schmidt Newtonian package is a lot of telescope for the price, especially when you consider Autostar. If your primarily an observer and its fast, wide field optics your looking for its unbeatable in its price range. For inquires I can be contacted at alanprowse@hotmail.com
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