Posts Made By: Alex McConahay

>>>>Let's hear it from Herb.

Herb is busy celebrating the demise of the Religion and Politics forums. Please don't ask his advice on this one.

Alex

If you get a good quality, rich field refractor, you can get anywhere from low power to high. With a ETX or other small Mak you can get generally higher power views, but you cannot generally get the wide field views.

You might want to get two different diagonals for whatever you get--one for correct image daytime, and the other for high light transmission night time observing.

Alex

Yes, you can do what you describe. I don't know where you can find a commercial one, (I used to have one for my Olympus)....But you can make one fairly easily by taking a rear lens cap and gluing it to a 1.25 to 2 inch eyepiece adapter. (Cut a hole in the rear lens cap!!!) Then, when you put the cap on the back of the lens, and stick an eyepiece into the 1.25 adapter, you have an eyepiece holder attached to your lens. (Or you can use a piece of pvc or copper pipe with a 1.25 ID.)

You won't get as good a view as you might expect because Camera lenses and telescope lenses have different requirements (as covered elsewhere).

Focus your contraption by sliding the eyepeice in and out, and moving the regular focusing ring on the camera lens. And you may have to make sure you have an adapter such that you can position the field stop exactly the right distance behind the end of the lens.....but with that warning, you can do what you describe.

Alex

Lee,

I is interesting that you ask these questions. THey are certainly the types of things telescope owners like to discuss on a cloudy night. THerefore, I think, that they tend to interest beginners. However, I am not sure that I give much thought to them any more as a practical astronomer with some experience. In short, they just aren't anything you have to worry about. A six to eight inch Dob cools to usefulness quick enough. Probably as quick as anything except a refractor. Collimation takes a minute or two once you learn how to do it. (It takes a whole lot longer to read the directions on how to do it than it does to actually do it--once you learn it. It takes a bit to learn it, though.) Either the eight or the six are on the same scale of bulk. The six is a bit easier, but either fits in a car pretty easily, and neither takes up all that much closet space. And neither takes much more than plopping down and sticking an eyepiece in it. (Collimation two minutes, aligning the finder, 30 seconds..... Eyepiece, fifteen seconds. Ready to view.)

>> I'm going to go to work and I'm gonna try not to look for answers until I get home. I'm gonna be good.<<

And, by the way, the computer at work is for work only--not for checking out Astromart.

Alex

Our club has built six or so roll offs. We looked at Sky SHeds a long time ago, but made substantial modifications to their p[lans and others to get them to work in the desert. THey are running about $3700 with concrete foundations and pier. That is up from earlier, because of standard skyrocketing materials cost.

Alex

The Eos Rebel is a great astro camera.

Whatever you do, go for something that has an interchangeable lens (a DSLR) rather than a point and shoot. That gives you a ton more flexibility and power.

The number of pixels is important if you plan to print large or crop. Otherwise, realize that the biggest image you will see most of the time is your computer screen, which is in the neighborhood of 1200 across its widest dimension.

Alex

Assuming it ends in a 1.25 or 2 inch focuser--sure, just get a camera adapter and t-ring from the nice people at Anacortes.

Alex

If it is a standard newt, the problem is likely in the eyepiece. Do you have this problem with all eyepieces?

Alex

Okay--so, here we are talking about how accurate the center of the dot has to be. I didn't follow the final results, maybe, but it was something like half a millimeter last I looked.

The spot on my laser collimator is at least a mm across--probably more. And, I actually don't spot it, I have a paper reinforcer with at least five or six mm across--

And, by the way, when I am looking at the dot illuminated by the laser--it is something like four or five feet away at least--

Okay, so here comes the question-- Just how closely can you measure the laser hitting the center dot with these conditions?

Alex

If you go out at exactly midnight (or any other time) each night you will see the summer triangle a bit further west than it was last night.

However, if you go out earlier one night than the last, it will appear further east than it was.

The summer triangle does some other weird stuff, though, especially as the summer wears on. As the summer goes on, the sun sets earlier and earlier. Therefore, if you go out an hour after sunset (which happens earlier each night) and look up, you will see the summer triangle hasn't appeared to move much. this is because you are actually looking at it earlier in the evening (further east) but it has moved further west. Therefore, it looks like it is hanging around a long time.

Alex