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Both my wife and I are casually interested in astronomy....not in a big way....but we will do things like get up at 2 a.m. to look at the red lunar eclipse, or to watch a meteor shower. Each time we do it, I say "we've got to get a telescope". During the recent lunar eclipse, I was watching it through the 20X scope on my bolt rifle, and that thing is too heavy to hold up like that for too long. I have wanted to buy a telescope for the last 25 years, and I finally got one. I consulted with a friend of mine who is an astronomer at NASA JPL and who owns a couple of his own personal telescopes. I was all set to buy something with onboard software and a "go to" system, but my friend advised me to go for unplugged mechanical simplicity in exchange for better optics, more magnification, and better light gathering.

So that's what I did. I ordered an Orion® SkyQuest™ XT8 Dobsonian Reflector telescope last Friday online from telescope.com, and it came today. It took me about an hour to assemble everything, but it wasn't that complicated. It was surprisingly affordable. I bought a bundled deal that included some extra eyepiece lenses and some other extras, and it was about $100 more than the plain telescope, but even with the extras it was $455.00, and the shipping was free.

This thing is monstrously large. With an 8" reflector and a dark enough sky, it can pick up very faint objects. Apparently, you can see the individual colors of binary stars, the spiral arms of galaxies in clear detail, the crab nebula, not to mention the planets in our solar system. Although it is pretty big, it breaks down into two components were are easily carried if I want to take it to a more remote location. I'm going to try it out for the first time tomorrow night in my back yard......if the weather holds. Even with the light pollution, it should still be pretty amazing. Here's what it looks like:





So do any of you have telescopes, and if so, what have you got, and what are you watching?

My wife has been begging me for one! That looks like a beauty. Is it compatible with a camera?

That's a nice looking gadget. Silly question but how do you look through that thing? Does it hookup to a computer?

We have a little refractor that got used a few times after a gave it to my wife years ago. The light pollution in each of our homes has been pretty bad, making using any 'scope a challenge, and I guess she was not as interested as she thought when she asked for it, so it even went unused during the recent eclipse. If I tried to wake her up in the middle of the night to look at an eclipse or meteor shower, I would be writing this from a hospital bed.

I too have always wanted a decent telescope, but don't know anybody who knows about these things so appreciate that you do. Let us know how you like it!

The Annoyed Man wrote:I have wanted to buy a telescope for the last 25 years, and I finally got one. I consulted with a friend of mine who is an astronomer at NASA JPL and who owns a couple of his own personal telescopes.

Will it fit on a rifle or should I say will a rifle fit on it.

You have probably never heard of aperture fever. You will.

The ability to resolve detail is governed by the aperture of your telescope. The bigger the main lens, in your case 8 inches, the more detail you will see. A telescopes maximum magnification is limited to about 50 power per inch. Thus you are limited to about 8 x 50 or about 400 power.

No matter what size telescope you have, some one else will have a bigger aperture, and will invite you to look through it. Don't. Otherwise aperture fever will set in.

Just one time I looked through someones 20 inch dob and my 8 inch scope was never the same.

Your choice of a dob is perfect. Low cost, big aperture. It looks very well made, which was not always the case with dobs 30 years ago. They have come a long way.

With an 8 inch you are right at the borderline of whether you can see the Cassini division in the ring (rings) of Saturn. With my 8 inch I cannot. With the improvements in manufacturing over the years maybe you will be able to see it. You will have to let us know. You should be able to see the polar ice caps on Mars, especially when it is in opposition. Hurry and see if Orion is still visible as the great nebula there is the best one to view. Unfortunately I saw it through the George telescope once and well you know aperture fever.

Enjoy.

I have a Kowa model T5-611 20 X 60 power mounted on a Bogen Tripod.

Primarily used for birding, but it's also great as a spotting scope for target shooting.

A good source of optic info can be had from Land, Sea and Sky in Houston.

Wodathunkit wrote:My wife has been begging me for one! That looks like a beauty. Is it compatible with a camera?

Apparently they can be made compatible with some kind of adapter, but I don't have that item yet although I do have a decent DSLR. My friend did say that photography with simple dobsonian telescopes can be challenging because A) the light values some of the observed objects are so small, and B) the scope doesn't automatically track the object being observed as the earth and the object move in relationship to one another. However, I think that with a good digital camera you can overcome some of those obstacles.

rbwhatever1 wrote:That's a nice looking gadget. Silly question but how do you look through that thing? Does it hookup to a computer?

The eyepiece inserts into that mount that is 90º left of the "muzzle" end of the tube. The eyepiece is not attached in the pictures. The object that is located where the "front sight blade" would be is a red-dot sighting device, without magnification. You look through it and place the red dot on the object you want to observe to orient the scope (or in some cases, the area of sky you want to observe (as the telescope is capable of "seeing" objects not visible to the naked eye), and then you look through the mounted eyepiece. To the best of my knowledge, it cannot be connected to a computer.

Like I said, if the weather permits tonight (there's some chance of large thunderstorms), I'll get it out to the back yard and see what I can see.

george wrote:There used to be group of astronomy typres that met out at the George Observatory south of Houston. That would be a great place to get involved and ask questions.

I don't know (yet) of any observatories or astronomy clubs in the DFW area, but I plan to find out. That idea had already occurred to me. When I was growing up, my family became close friends with Max Delbrück's family, one of the benefits of growing up in Caltech's environment. Our families went on an annual camping trip to Joshua Tree National Monument each year, and each year, one of the features I always looked forward to were the night-time walks that Max would lead out into the desert away from even the light pollution of the primitive campsight, where he would give an always informative talk about all the stars that we could see with the naked eye.

On one such weekend, our informal star-lecture group bumped into an astronomy club which had brought out all their telescopes to the middle of the desert. One guy had a dobsonian like mine, but much larger.....maybe a 12" or 14" reflector....and that was the first time in my life that I saw a spiral galaxy in clear detail. It remains today one of the most beautiful things I've ever seen. My wife had never been to France until the time I took her there in 2005. All of her life, she had seen a million pictures of the Eiffel Tower, but never the real thing. On the day we went to visit it, I deliberate took us by a route where she would not be able to see it until we rounded the corner of a large museum building, and then BAM!, it burst into view. The magnificence and the startling reality of it made her cry. That is how I felt when I first saw a spiral galaxy in clear detail through a telescope. For me, it is a religious experience. Literally. What better way to grow in the knowledge of God than to take in the beauty of His far-flung creation?

suthdj wrote:Will it fit on a rifle or should I say will a rifle fit on it.

To put things into perspective, my Remington 700 .308 all up with scope and rings weighs 11.5 lb. This telescope all up with tube and base weighs 41 lb. If not for the internal workings of the scope itself, I could put my .308 inside the telescope tube and close the dust cap. Conclusion, I probably won't be using this thing as a spotting scope at the range any time soon.

philip964 wrote:You have probably never heard of aperture fever. You will.

The ability to resolve detail is governed by the aperture of your telescope. The bigger the main lens, in your case 8 inches, the more detail you will see. A telescopes maximum magnification is limited to about 50 power per inch. Thus you are limited to about 8 x 50 or about 400 power.

No matter what size telescope you have, some one else will have a bigger aperture, and will invite you to look through it. Don't. Otherwise aperture fever will set in.

Just one time I looked through someones 20 inch dob and my 8 inch scope was never the same.

Your choice of a dob is perfect. Low cost, big aperture. It looks very well made, which was not always the case with dobs 30 years ago. They have come a long way.

With an 8 inch you are right at the borderline of whether you can see the Cassini division in the ring (rings) of Saturn. With my 8 inch I cannot. With the improvements in manufacturing over the years maybe you will be able to see it. You will have to let us know. You should be able to see the polar ice caps on Mars, especially when it is in opposition. Hurry and see if Orion is still visible as the great nebula there is the best one to view. Unfortunately I saw it through the George telescope once and well you know aperture fever.

Enjoy.

philip964, I'm already there. I've already looked through a larger than 8" dobsonian. BTW, I thought of it in terms of "aperture envy".

The funny thing is that I saw your response literally right after talking to my wife about larger telescopes. I bought what I could afford for now, but I already plan to invest a few $K into something larger down the road. This one was $455 for a bundle which included a couple of additional eyepieces, a 2X barlow lens, a lunar map, a moon filter, a cardboard Star Target, the red dot reflex sight, a "Star Theater" DVD, and a copy of the Starry Night software on CD. Since the base telescope without the additional stuff costs $350, I figured this was a decent price. (I already had an older version of Starry Night 6 digital download on my desktop unit, so I'll install this copy on my laptop.)

In any case, I can see that this is going to be trouble. I don't have the budget to cover both a gun AND a telescope addiction.

philip964, if you are aware of any groups that meet in the DFW area, can you PM me or post it here to let me know?

Thanks.

TAM - It looks like a nice telescope. I don't have one of my own, but have used my brother's for many years. He is a very experienced astronomer.

I would like to give you a couple of hints to improve your viewing pleasure.

First the large scope that you have and the high power magnification make it harder to find your object and keep it in the field of view [just like a rifle scope].

I always found it hard to find the star, planet etc in the view finder and have it centered in the eyepiece. I think that's more a matter of practice.

It sounds like the red dot might elimination a lot of that issue.

You might want to look into a motorized mount that tracks with the earth's rotation. With high magnification and small field of view the stars and planets move faster than you would think.

This is especially important if you want to take photos since most take long time exposure.

Don't assume that the higher the magnification, the better you will be able to see. I am sure that you know that from your shooting experience.

It looks like they designed the scope with the mount near the bottom. Hopefully this adds some stability so that bumping into the scope doesn't move it too much.

The temperature change between the house where your scope is stored may be different that outside where you are viewing. Sometimes it helpful to put your

scope out for a couple hours to equilibrate. You will get clearer viewing that way. Happy viewing!

Here are a couple of pictures taken by my neighbor's son. His telescope is also an 8 inch reflector.

http://glogg.jupiter-io.net/display.aspx?ID=24

http://glogg.jupiter-io.net/display.aspx?ID=123

WildBill wrote:Here are a couple of pictures taken by my neighbor's son. His telescope is also an 8 inch reflector.

http://glogg.jupiter-io.net/display.aspx?ID=24

http://glogg.jupiter-io.net/display.aspx?ID=123

I'm instituting a self imposed moratorium on this thread or I'm gonna go bankrupt. Awesome photo.

I thought I had that slavering beast of a "I want a Dobson" safely locked away in a dim, dark recess. I avoid web sites, blogs, and articles that might release it. And then I get blindsided on a gun forum!?!?!?

Sheese!

Bill, Orion sells a version of my telescope with a motorized mount, but it costs $1,030 compared to the $450 I paid for mine. Out of curiosity, I phoned them after reading your comment to see if the motorized base was offered separately, and it is not. The lady told me that in their manufacturing process, each telescope is put together as a package deal as offered on the website (telescope.com), and that they do not manufacture the base components separately from the telescopes themselves. I was not rude and did not point out to her that they DO sell separate motor drives for other kinds of telescopes on their website, but I did tell her that I thought it was a mistake not to offer dobsonian mounts separately. I said that there must be a ton of customers who previously paid $350-$450 for an 8" dobsonian that are NOT going to pay another $1030 for a second copy of the same telescope just so they can get the motor and drive gear, but who would probably be willing to pay a third to half of that amount down the road in order to motorize the base they already have. I certainly would be willing....not now, but in the not too distant future.

One upgrade I'm probably going to invest in down the road is a laser-pointer finderscope, but it's not absolutely necessary. The main thing is, I've got to be patient and take the time to learn how to use this telescope as is. I realize that celestial objects will be moving relative to me, and I have already seen what that looks like in a non-motorized dobsonian. It's not THAT big of a deal to give the mount a small nudge once in a while to bring the observed object back into the center of the field of view.

The scope's altitude bearings are located such that they provide near perfect balance of the tube. There are retention springs on either side where it mounts to the base that ensure that the proper amount of tension is kept against the bearing surfaces of the pivot points. The resistance to rotation in the base is controlled by how tightly you screw down the nut onto the bolt that connects the bottom plate to the swiveling plate. The bolt rides in a polymer insert as it passes through the swiveling plate, to reduce friction. And then both the tube mounted altitude bearings rest on teflon bearing pads, and the rotating base sits on similar pads located on the bottom plate. So the entire assembly has enough resistance to movement to dampen out unintended changes, but enough ease of movement to make it fairly easy to change the angle in either plane.

Base Assembly Instructions:
[youtube]http://youtube.com/watch?v=pxo9uVqDOFc[/youtube]

Mounting the Tube to the Base:
[youtube]http://youtube.com/watch?v=qdNhdKqWX-k[/youtube]

I also found this video, shot through an XT8 dobsonian using an iPhone 4 to record lunar footage, in a 20 mph wind:
[youtube]http://youtube.com/watch?v=D7zEfKpC8WU[/youtube]

Lastly, here's some good advice on telescope selection for first time buyers:
[youtube]http://youtube.com/watch?v=sAzhOSbxMiI[/youtube]

I also found this useful review of Orion XT8 dobsonians: http://www.universetoday.com/91221/tele ... reflector/