Ghosts in the Machine: the Astro-Tech AT111EDT...
Jun 13 2015 11:23 AM by jrbarnett
My NexStar 5 Journey
Jun 13 2015 10:29 AM by orion61
Review of the William Optics 102 GT
May 25 2015 11:22 AM by Perseus_m45
Review- Printing Astro photos on Metal with Bay...
Apr 16 2015 02:36 PM by ScenicCityPhoto
Categories See All →
- CN Reports
- User Reviews
- How to . . .
- Observing Skills
- Astronomical History
- Optical Theory
- Vision and Related Experiments
- How to Gain the Support of your Family for your Astronomical Pursuits
- Evaluation Tips
- Special Events
- The Elements
- New Articles in [!monthname!]
- Telescope Articles
- Submit a Review / Article
- Monthly Guides
- Behind the Scenes
- About Us
- Copyright ©
- Terms & Conditions
- Tiny Eyes on the Skies
- From the Editor's Desk
- What's Up . . .
- The Light Cup Journals
- Who is this Super Light Cup?
- Cloudy Nights T-Shirts
- Imaging Contest
- Small Wonders
- Previous Imaging Contest Winners
- This Month's Skies
- Mike's Corner
- The Cloudy Nights Friends and Family Discount
- Uncle Rod's Astro Blog
- Fishing for Photons
- Binocular Universe
- Article Submissions
Meade's 102mm Achromat on LXD500 Mount. A refractor for the budget-minded and a great telescope for the urban astronomer
In today's age of computer controlled, micro-precision mounts, and expensive refractors with optics constructed from exotic elements to eliminate false color; the traditional achromatic doublet refractor has lost considerable popularity among amateur astronomers. In truth, why would an amateur even consider an achromatic telescope? With false color usually a major problem, is it not better to either purchase a good reflector, cassegrain, or save those pennies for a high-end apo? There are two reasons that the age-old achromatic refractor is still a telescope to consider: sharp, contrasty views, and price.
Meade's 4-inch achromat on the LXD500 mount. Piggybacked as a "finderscope" is an Orion 80mm Shortube, despite this additional weight, the LXD500 mount still provides adequate stability. Despite false color, the achromat provides the sharp, contrasty views for which refractors are renowned.
I first came across the Meade 102mm Achromat when I sold my computerized cassegrain in December of 2000. The achromat was proudly shining in the showroom of my local telescope dealer, and I simply could not resist its fabulous appearance. The model I obtained was a used version, and included the Meade 1702 Electronic Drive System (reviewed below). Of note, this telescope is the 1998 version and as such had the $995.00 price tag. I have yet to read any information that notes whether Meade cut more than the prices with the newer versions of this scope.
Overview and Initial Impressions
The telescope physically looks great with its stark white, seamless optical tube and battleship gray mount. The majority of the instrument is constructed out of quality aluminum, save for a few various knobs, which are plastic. Overall, however, none of the parts seem structurally weak and the entire unit has a degree of sturdiness in a lightweight package appeal. The total weight of the telescope is 47 pounds, but seems much lighter. This weight is even less a factor thanks to the ease at which the unit can be disassembled for field use and transport, with the heaviest component being the equatorial head at only 19 pounds (the tripod can be easily left attached to the head, in which case the mount's weight is around 25 pounds). With such lack of bulk and compactness of the telescope, I thought the instrument would make an ideal scope for the city amateur astronomer, as moving the unit up stairs or maneuvering it to avoid glaring lights would be easily done. The telescope can also be traveled with to some degree. With ingenuity, the entire optical tube, equatorial head, and tripod could be accommodated in a single large suitcase (definitely not a carry-on, however).
The Optics & Optical Tube
The telescope is as advertised: an achromat. Perhaps because of this fact, I initially held low expectations of its optical performance, yet I had been very pleased with other achromats I owned in the past. Needless to say, I was pleasantly surprised.
Reflecting a very bright flashlight off of the optics reveals the green-violet hues characteristic of multicoated lenses. Despite the fact that bright reflections off of an objective designate insufficient optical coating, the refractor provided high-contrast, sharp views even in areas abound with heavy light pollution and glare.
The optics with my sample of the Meade 102 are fairly well coated. While there is some reflection of bright light (such as a flashlight), the reflection is less apparent than it is in my 80mm Shortube. The objective lens cell features three allen-head screws allowing for collimation of the optics, but I found that no adjustments necessary. Looking down the optical tube reveals a good coating of flat-black paint and three well-placed baffles, while using a flashlight shows no noticeable internal reflections. Under a star test, the Meade 102 Achromat demonstrates a clean airy disk with fairly sharp edges. The disk remains nearly identical in appearance and position on both sides of focus. With low and mid power eyepieces, the chromatic aberration experienced when viewing through the scope is rather mild. Only on stars or objects brighter than about 2nd magnitude is the spurious, violet halo noticeable. Yet with high power, the chromatic aberration becomes quite distracting, even with relatively dim stars.
The sharpness and contrast, though, are the definite strong points of the instrument. Stars appear as beautiful little pinpoints at low and medium powers, and the focus simply snaps into place unlike the constant fickle I experienced with all three of my cassegrains. The background sky is a rich dark color in the telescope, even when peering into the yellow-white haze of my southern skies using fairly low powers. For comparison, my Orion 80mm Shortube seems to have less chromatic aberration, but perhaps that is because the Shortube is a much faster instrument (f5 compared to the Meade 102mm Achromat's f9) and thus is less apt to be used for high power viewing.
The LXD500 Mount & Tripod
The optics make up only one-half of the telescope, and without a good mount, even the best optics in the world will be practically useless. Fortunately, the LXD500 mount accompanying this telescope is quite good and is suited for visual observing. The latitude adjustment on the LXD500 accommodates a range from 15 to 70 degrees, making it acceptable for use nearly anywhere in the world. Firm, rubber-edged aluminum knobs provide a series of fine adjustments for polar alignment of the mount, to include micro-adjustments in both vertical and horizontal, as well as a micro-adjustment for the latitude position. After many times setting up the scope, I have found all of these micro-adjustments work very well, although the fine-latitude adjustment can be a little tight. Knurled washers are also featured on all of these adjustments, so that the mount can be locked in place once good polar alignment is achieved. Lock levers are featured on both axes. Once the telescope is balanced, however, the mount provides smooth motions and keeps the telescope pointed at its targets no matter what position. The only time I have had to use the lock levers is when using a large, Nagler-type eyepiece, for the additional weight would otherwise require rebalancing the scope. Two 7-pound counterweights are included with the unit, but only one of these is necessary unless you will be adding equipment additional to the finderscope and optical tube. I am pleased to say that the mount easily accepts the additional 5-pound weight of my Orion Shortube, and performs very well. With the tripod fully extended, the setup becomes a little shaky. If you use an observing chair or stool, however, the tripod will need to be extended only partially, thus providing a fairly stable support. On one evening I was going over some features of the moon at higher powers. Despite winds of 15 miles-per-hour and higher gusts, the mount kept the image very still with only some jitters during wind gusts.
The LXD500 mount is not without its share of problems, however. With my somewhat rough handling of the mount in transporting it inside and outdoors, the latitude position does tend to work slightly out of adjustment, but this is easily amended with each observing session. Bigger problems rest with some of the knobs. Both lock levers can be rather easily unscrewed from the mount if turned too far in the unlock position, and many times have I turned them the wrong way intending to lock the scope in place when the little lever fell out. My biggest complaint with the mount is the axis slow motion controls. Their simple plastic design simply does not work too well and provides only marginally acceptable control for using the telescope with high power. Worse still, the ridged knobs tend to get in the way of the mount, rendering observation in certain conditions (such as southeast) impossible. Fortunately, as with the other problems, the solution to this difficulty is very simple: remove the slow motion controls. They are attached with a single thumbscrew and if the mount is well balanced at the start of an observing session, good control can be had manually. A problem that cannot be corrected is the fact that the LXD500 mount is a light-duty system, and because of the mount's absence of good slow-motion controls and lightweight nature the centering and observing of targets at high powers could be somewhat frustrating.
Of note, the Meade instruction booklet states that there are (or were) two versions of the LXD500 mount: one having bronze gears and one having aluminum gears. My version of the LXD500 mount has the bronze gears, and I would highly recommend that anyone considering an instrument that includes this mount be sure that their LXD500 is one with the bronze gears.
The Meade 102 Achromat comes with several accessories to include: a 6x30mm finderscope, 25mm plossl eyepiece, and a 90-degree diagonal prism. The 6x30mm finderscope is fairly good, although was originally badly out of focus. By rotating the objective cell of the finderscope, I was able to achieve good focus, but stars still appear very mushy towards the edges. For general centering of brighter stars and planets, the provided finderscope works adequately, but I'd suggest replacing it for serious observing. For this reason, I put the finder into storage and adopted my 80mm Shortube and its 6x30mm finderscope for centering objects in the telescope. The 25mm plossl eyepiece is an excellent accessory, provides pleasingly wide fields and is very sharp. The provided 90 degree prism diagonal is another story altogether and is by far the worst aspect of the entire telescope. I would definitely not trust the cheap plastic design of this diagonal for supporting any large eyepiece. Additionally, the locking screw of the provided diagonal works its way loose, making it easy to mistakenly have an eyepiece fall out when moving the scope around its polar axis. I was sure to loose this accessory at first opportunity and use a high quality Lumicon 90 degree mirror diagonal instead. My telescope salesman was very generous in giving me $25.00 for the cheap Meade prism diagonal.
1702 Dual Axis Electronic Drive System
According to Meade literature, with the incorporation of the 1702 drive system, the LXD500 mount becomes suitable for astrophotography or CCD imaging. While I can see that this electronic drive may have been intended for such use due to its serial port for an autoguider, the fact is that neither the drive system nor the motors are up to such delicate tasks. The motor drives tend to slip in griping the simple bar that extends from within the mount, providing for somewhat random operation (this is not a gear problem, but the inadequacy of the motors provided with the 1702 drive system). The 1702 drive system can be used for high power observing, but is not even remotely capable of turning the LXD500 mount into an astrophotography or CCD imaging rig. I really cannot recommend spending $195.00 on such a drive system.
Observing with the 102mm Achromat & Conclusions
The real test of any telescope is its use and performance for observing. I have used this scope for five months
now and have been fully satisfied. From my typical suburban backyard, the telescope shows M81/82 as two fabulous
galaxies in one eyepiece field. M82 appears as a slightly mottled, elongated glow, while under careful scrutiny
I am almost certain that M81 seems to show a hint of its spiral arms. M98 shows up clearly, but is easier with
the help of a narrowband light pollution reduction filter, and M104 easily reveals its famed dark lane. The telescope
has some serious capability as a deep sky instrument. I have used it to log a number of NGC galaxies including:
NGC 3077, 3953, 4088, 4100, 4102, 4754, and 4762. Most of these show some character with careful scrutiny. On the
planets, the scope is somewhat lacking. Due to the chromatic aberration, higher powers render planetary details
invisible, to include obscuring Saturn's rings. Still, using Wratten filters, the spurious color can be suppressed
enough so as to make the telescope acceptable for enjoyable glances at the planets.
The Meade 102mm Achromatic Refractor and LXD500 mount combination make for a great telescope for visual use at low and medium powers. While some reviews of Meade refractors have noted problems with the optics and lens cells, I have noticed no problems in these areas with this scope. The unit does demonstrate some chromatic aberration that is severe enough to warrant limited use for the observation of bright targets and planets, but on deep space, the telescope truly excels. I have to remark that this is perhaps the ideal deep-sky telescope for amateurs bogged down by light pollution, for the enhanced contrast the instrument offers compared to other designs allows the telescope to punch through washed-out areas of the sky. Indeed, a high quality apochromat will be able to do the same and perform better on the planets, but the cost difference is significant ($695.00 for the Meade 102mm Achromat on an LXD500 compared with an average cost of $2000 for a 4" apochromat, optical tube assembly alone). A good example of how well telescope performs is the fact that in four years of amateur astronomy, I have owned eight telescopes. This Meade 102mm Achromat is only the second one I have been satisfied enough with to keep.
Meade 102mm Achromat Recommended Accessories
- Better finderscope ($35.00 - $65.00) for 6x30mm, recommended brands: Orion, Antares
- Quality Mirror Star Diagonal ($50.00 - $100.00) recommended brands: Lumicon, Televue, Orion
- Meade #812 Polar Alignment Scope ($50.00)
Meade 102mm Achromat Quick Review
|Positive Aspects||Problem Aspects|
|Sharp Optics||Provided mount is for light-duty use|
|Good Contrast||Poor Performance on planets|
|Great physical appearance||Provided mirror diagonal is almost junk|
|Light weight and portable||Small aperture could fast lead to aperture fever|
|Relatively low cost|
Although cloudy skies combined with a bad mosquito situation have combined so as to really limit my observing, the Meade 102 Achromat continues to be my primary telescope. As a testament to how satisfying this achromat really is, I decided not to purchase an apochromat, instead considering perhaps a Celestron 9.25" or an Orion 10" Dobsonian (yes, "aperture fever" never does quite go away).
Several readers told me that the problem with the stability of the scope rests not with the equatorial head, but much more with the tripod. I can very much agree, although the equatorial head on my version still does have some play. A good way to improve stability, as many readers informed me, is to replace the thin aluminum tripod legs with sturdy wooden ones. I will be making this change in the near future. I have noticed that Universal Astronomics offers wooden surveyor's tripods that appear very well built and are listed as being available for telescope or binocular mounts. I suspect that the wooden legs of their tripods would be easy to fit onto the LXD500 mount. I would be most interested in receiving word from readers who have changed out the aluminum legs in order to determine what company makes wooden legs that are easily attached to the LXD500.
Another easy mount fix that readers brought to my attention is the changing of the annoying slow motion controls to cable type. If someone can refer me as to who they purchased a cable type slow motion control that is compatible with the LXD500 mount, I will include that information here on a later update.
I have also received word from a small number of readers who note that their 102 Achromat optical tube assembly came with something loose inside the lens cell. From other reviews of this telescope, this appears to be an occasional problem. Fortunately, in all cases, it is reported that Meade has been fair in fixing the problem, although the wait might be a little longer than most would desire.
Finally, I was thinking that it might be easy to add a few thin slices of Teflon in the focus assembly so that the focuser can be improved. I urge those of you who have skills in tinkering with telescopes (unlike myself), to try this improvement; and be sure to let me know if you can make such an improvement.
I continue to enjoy using my Meade 102 Achromat, and can continue to recommend it to other amateur astronomers who seek a very portable telescope that can offer the crisp views for which refractors are known for. At the bargain prices some people have reported, this telescope is, in my book, one of the best values on the amateur astronomy market today.
Side note: I received word of a rumor that Meade was discontinuing the manufacture of the Meade 102 Achromat. After some investigation by my part, I could find little evidence of this other than a single major dealer no longer carrying this telescope in stock.
- Special thanks to those readers who contacted me with tips, suggestions, and comments.
This photograph of the sun was the result of a whimisical experiment with the Meade 102 Achromat equipped with
an Orion Solar Filter. A Canon "Sureshot" 35mm automatic camera was hand held to a 28mm Orthoscopic eyepiece
to take the photo. This is an unenhanced image that was recorded on standard 100 speed Kodak 35mm film.
Jay Michaels is an avid amateur astronomer who enjoys plumbing the skies for deep sky treasures. During the day and when stormy skies render observing impossible, Jay will be manning his full featured meteorological station, WXPSJ1 or training his German Shepherd. Jay also enjoys cheering on every space shuttle launch, as his location only seven miles from the Kennedy Space Center allows for wonderful launch views from his driveway.