Meade 8" Deluxe F/6 Lightbridge Truss-Dob Telescope?

Question

Anyone know what the telescope above is like. Are there any advantages/ disadvantages to having a Truss-Dob to an ordinary Refractor or reflector?

Answer 1

If you are planning to get a dob scope, this is a good choice. Total weight is only 44 lbs, but it breaks down into light components. It looks easy to set up, comes with a cooling fan to help speed that process along. Altogether a good choice.

The open truss reduces weight, but a good dark sky site will be helpful, too. If stray light where you are is a problem, a shroud made from a black trash bag would do nicely.

F/6 makes it fast enough for many dim objects, and the 8" aperture makes splitting many double stars possible.

Yes, a good choice. You should be able to see all the Messier objects with it, though a few will be challenging. I have never been able to see the horse head nebula in anything less than 12" but other swear they can. That would be an interesting test for such a scope. You will need *very* steady and dark conditions, but if your eyes are sharp and you know what you a looking for it is on the very edge of possible.

Good luck!

HTH

Charles

Answer 2

For the 12-inch and 16-inch, and possible the 10-inch, I can see distinct advantages in moving them around and putting them in small cars.

For the 8-inch, I can't see what the problem would be with a solid tube like the Orions. I'm not familiar with them, but I believe they tend to be longer than the old Meade Starfinder tubes, so maybe an Orion 8-inch wouldn't fit in the back of a Mini (like it shows in the Meade ads), but I still think that the truss is more practical with the bigger ones.

And Meade is a funny crowd. I've never had any problems with local dealers, but the service at the main centre gets mixed reviews. Granted you only hear when things go wrong, but ensure you have full warranties and a reputable dealer.

Advantages? Portability and (dare I say it) quality. And they look great! Disadvantages? Obviously having to set up and collimate. It wouldn't take long, but you wouldn't like to disassemble it with cold fingers, either.

Answer 3

It's a very nice telescope------- it breaks down into smaller parts so it is easy to carry in and out.

However------- also look at an Orion DOB, and a Zhumell DOB--- I would recommend a 6" or 8" Orion Intellascope as a good quality "pushto" computer DOBsonian.

You need to collimate a reflector--- not really very hard to do. And the BANG for the buck is better in a reflector of 6" or 8" in size-------- lots more light gathering power than a 3.5 inch refractor. (However a good refractor is usually better on planets------- and yields a somewhat sharper image than a reflector. BUT-------- good APO type refractors are very expensive!)

Answer 4

Sir:

The advantage of a Truss-Dob telescope lie within the
area of usefullness. As you go to larger and larger mirrors
in telescopes, the weight factor begins to get really serious
when one considers the necessity to move a scope from
dry storage, outside to a suitable viewing spot.

Instead of having a solid tube housing around the mirror and the second stage mirror + viewing focuser mounting, the Truss type Dobsinian uses rigid spars or hunks of rods or tubing to form the outer shell of the telescope and hold the second stage mirror + viewing focuser at the proper distance for viewing and focus. It is essential that those parts be held rigidly in place over the mirror base or views will wiggle in and out of focus, in and out of view - because of the high powers of magnification that are often used.

Dobsinian type telescopes use a rocker type cradle to hold the telescope tube in place while also allowing it to swivel in elevation and also in azimuth. This differs considerably from the normal heavy duty tripod assembly that is used with larger telescopes of the 8 inch mirror or objective lens variety. Some of those heavy duty mounts weigh 100 Pounds or more, and are unweildy to carry here and there. This cumbersome quality tends to limit the number of times that someone might actually take the telescope outside and use it. It is much more practical to choose a device that is light weight and easy to move around, thus making usage very simple.

Answer 5

Hi Tailfish -

It is a good choice. The only disadvantage to truss dobs is that they tend to pick up ambient light more easily because there is no tube to limit the light to the target - so you may get an image with a little less contrast. This can be avoided by wrapping fabric around the trusses as a "pseudo-tube" - this may also cut down on dew issues on the mirror.