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Meade LXD55 - AR6 Achromatic Refractor
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About a year ago I purchased a Meade LXD55 - AR6 Achromatic Refractor. This is my first "real"; telescope, and I thought long and hard about it before buying this particular telescope. A lot of people out there (on the internet especially) advised against a go-to scope as a first telescope, and the conventional wisdom was to get a 6-8 inch Dobsonian mounted reflector instead. Also advised heavily was to go to star parties and look through other people's scopes before you decide to buy one for yourself. Well, I haven't been to a star party yet, although I plan to sometime in the future. And I thought that I had my reasons for getting a computer controlled German Equatorial Mounted scope. First of all, I planned to use the telescope to do prime focus deep sky photography and had already procured a really cool vintage Nikon F1 camera for just that purpose, and I thought that the GEM was what I needed.
Well, as it turns out, the conventional wisdom is probably pretty wise. I haven't done very much prime focus photography yet. The main reason being that it's pretty hard to do, and the pictures that I have taken don't look very much like the ones you see in Sky and Telescope (duh). Yet. But, I haven't given up either. Mostly I've just looked through the telescope and learned how to set it up and use it almost competently. In the process of figuring it all out I've worked out a pretty easy method for getting the whole thing aligned and "going to". I've found that the process in the owners' manual (and most other places you find it) is made unnecessarily complex with several critical steps.
This process takes a lot of the critical set up out of the process of getting your LXD55 scope polar aligned. It works, and you should try it.
Of course you need to set up in a place where you can see Polaris, and of course you need to have everything lined up so that the polar alignment scope, finder, and main scope are all pointed at the same thing when you are in the German North position, but I'm not going into that. It's in the owner's manual, and you could probably do it without any instructions anyway. Anyway, assemble the GEM to the tripod, and point it roughly at the North Star, move the tripod around if you need to and look through the polar alignment scope to make sure that Polaris is well inside the field of view. No need to get too anal about centering anything up yet because the weight of the scope and counterbalances is going to make it shift a little when you add them. Also, there is no need to get too worried about leveling the base. I've seen it stated that leveling the base accurately is VERY important, but it's not really. Now, go ahead and finish assembling the rest of the telescope just like the manual says, but with one big exception: Don't use the battery pack that came with the scope if you want acceptable performance. It just doesn't do the job. I use a 12 volt wall wart from Radio Shack which works great for less than $20. If the weather is warm, and you are just dying to get started then the battery pack will barely work, but it's really a waste of 8 d cell batteries in my opinion. (The motors make a labored, sluggish sound when running on the batteries, even brand new ones, even when it's warm. If it's cold the computer will just shut down.) Alright, you're all assembled, now it's time to line everything up for real.
Here's Nifty Trick Number One. Look at the position of the next star from Polaris in the little dippers handle in relationship to Polaris. Make a note of this star's position as being at 3 o'clock or 5 o'clock or whatever, according to its position relative to Polaris. Now look through your polar alignment scope and rotate the scope around the polar axis until the little circle on the graduated vertical reticule marking is at this same position in relationship to the crosshairs at the top of the reticule. 3 o'clock or whatever the star in the little dipper was at. Now with your scope still in this odd position use your fine adjustments to put Polaris in the little circle that is part way down the graduated reticule. This will make the cross hair reticule and thus the equatorial mount's polar axis point right at the polar axis in the sky, which is not quite at the location of the North Star. This is the critical adjustment, not leveling the tripod. It took me a while to figure this out, which caused much frustration in trying to get the scope to point and track with any accuracy at all. Now unlock your declination and right ascension clutches again and turn the scope until it is upright and pointing at Polaris, and then lock your clutches back down again. Don't fret about getting either axis perfect, it just doesn't matter. Just point the scope at the North Star and pretty much upright and lock it down. Now turn on the Autostar and let it initialize, and enter the time as close as possible (again the exact time isn't important, but get as close as possible) and select "Easy Alignment" (2 star).
Now Nifty Trick Number Two. When the scope slews to the alignment stars, don't even look through the scope, just hit Enter and wait for it to finish, and for the Autostar to proclaim that the alignment was a success. Now chose a fairly bright, easily identifiable star that is not too far from the celestial equator and do a "go to" to that star. Most likely, the scope will not be accurately pointed at your chosen star (but it should be pointed to the general area in the sky where the star is, if you put in the right date, time, and time zone). So, after the scope completes it's "go to" to Pollux for example, unlock both clutches again and manually point the Scope at Pollux (Or whatever star you have chosen). Once you have it well centered up in the main scope's field of view (using fairly high magnification), lock down both clutches again. Now, put in your lowest powered eyepiece and you should be able to do reasonably accurate go-tos that will put those hard to find deep sky objects near the center of your field of view.
If you are thinking about buying one of the LXD55 series of telescopes you might be interested in my opinion about the one I've been using for the last year.
Generally I'm happy with the overall package. It was all that I could justify spending on a telescope, and I feel like it was good value. Now, however Celestron has similar deals on Computerized GEM mounted scopes that would certainly be worth considering. They just weren't available at the time I bought my scope.
I think that if I had it to do over and I was still going to buy an LXD55 I would get one of the Schmidt Newtonian models instead of the 6" refractor that I did get. My refractor gives some very satisfying views of brighter objects, and I don't really have a problem with the optics, but I think that a faster scope would give better views of the dimmer deep space objects. But really, the biggest reason why I would get a Newtonian OTA now is that the refractor is so difficult to look through when it is pointed near the Zenith. With the scope I have, you literally have to sit on the ground to get low enough to look through the scope a lot of the time. If the tripod were about a foot taller that situation would be considerably improved, but it might be too unstable. I plan to build a taller tripod and find out.
The Computerized mount is really great when you are trying to find something that is too dim to see with the naked eye. However, I think that perhaps this particular mount may not be suitable for astrophotography, because the periodic error is very pronounced at high magnification. Also it looks like it would be very hard to guide out even with an autoguider, because it is very quick and about half the diameter of Jupiter. I'm just guessing here, because I've never used an autoguider, or manually guided. Also at lower magnifications like at prime focus it might not be a problem. Someday I'm going to try it and find out for sure. Also, at low speeds the mount is very slow to react to commands from the hand box. This seems like it would make it hard to guide manually. Maybe it wouldn't.
This telescope is a good bit of trouble to set up and take down. Now that I've practiced, I can get it going in about 15-20 minutes, and put it away in 10-15. That really isn't so bad, and I'm sure it's no worse than any other GEM mounted scope. The point is that, on the occasion that you would just like to take a quick look, it just isn't feasible because of all the time involved in setting up and putting away the scope. That's why I'm working on building a Dobsonian.
I'm certain now, that one scope can not do it all. I'm also pretty sure that it's going to take me quite a while to become proficient enough to do any kind of satisfying deep space astrophotography, and this scope just may not be suitable for that purpose anyway.
So, what is my conclusion? One should probably attend a star party or two and look through other peoples' scopes before you decide on buying one for yourself. Also, I would probably get a Dobsonian for my first real telescope. Those new Orion Dobsonians that have digital setting circles look pretty cool.
I did take this picture through my lxd55, but the moon is pretty easy.