Posts Made By: Alex McConahay

Luis,

I have not tried the Lumicon. But my thoughts:

Why would anyone go with an off axis guider on a refractor. It can be so difficult finding a guide star, and getting into position to guide off of it, complared to a separate guide scope.

I know about differential flexure, and you have a good point that your mount is already heavily loaded----but still, Off axis guiding is such a pain in the butt.

I can see that it is a good idea with mirror shift in an SCT--but I do anything to avoid Off axis guiding.

Alex

Besides whatever else you have been told, one other point.....If you are in a truly dark site, flocking does not add anything (especially if you have taken care of any obvious bright spots (like unpainted screws, etc.)

Alex

Eightinch Dob wins in almost every way I can think of unless you have astrophotography in mind.

Alex

In the simplest of worlds, you are right.

Hopefully, though, we have moved past a child-like, oversimplified, view.

For instance--why did we have a day of prayer after an "act of God" destroyed New Orleans. Did God not know what he was doing in the first place when he destroyed the city? Are we supposed to change His mind after the fact? What was He after?

(And please don't tell me, in a child-like way "God works in mysterious ways!").

DOes God--the Dad in your story-- purposely set us up for failure. Does he purposely stand in front of a plate glass window and say--"Throw the ball!!!"

I don't think so.

Alex

This link has info regarding launch and photography

http://www.spacearchive.info/

Alex

Yes. You can put setting circles on alt-az mounts. THey tend to use degrees of azimuth and altitude, though, not RA and Dec.

Alex

Here's one from southern Riverside:

Alex

Get something good and strong to carry the head in.

Obviously you need the dovetail plate and radius blocksand/or rings to attach the main tube to your saddle plate. You do not need Losmandy accessory rings, balance system, etc. for attaching guide scopes, etc. (at least as part of the basic mount. You may want them for other purposes.)

I think the metal motor covers seem to help over the plastic ones, and certainly over the old rubbery kind.

The knurled knobs don't add much functionality. I've never seen need for the clutch handles.

You may want to consider the upgraded worm gear if you are taking pictures.

I don't knkow what kind of plate they send (if anything) with a new scope that attaches to the two ears that stick out the side of the tripod head. (Maybe they don't send anything--does the electronics box connect directly to it--I forgot, It has been so long since I used the tripod.) However, it is nice to put the electronics box in this position if possible. One can be made very easily, or, I understand there are several after-markets for this.

Alex

Try DSLR Focus, but realize that you have to have a computer hooked up. (Also, I find the product is still very buggy with my 20D.)

You can also try to snap a picture, call it up on the screen, and zoom in. Then adjust focus, and try again as needed.

The STI products work pretty well, but are expensive.

Alex

Ben,

You said So a typical 8" cassegrain telescpe has a focal ratio of 80" (of course the ratio is f/10).. when you meant to say So a typical 8" cassegrain telescpe has a focal LENGTH of 80" And, if you meant focal length, you are right.

The amount of light one gathers is generally dependent on the aperture. It determines how faint a star one can see. But, as has been pointed out, the larger apertures usually come with shorter focal ratios (lower numbers). This is partly for convenience--it they did not, the tube wouold be too long, and the ladder too high.

So, why does one want more focal length--Well, focal length determines magnification, for any given eyepiece. The more focal length, the more magnification.

Also, it is harder to make a quality short focal ratio telescope. It is much easier to make an F10 than an F4.5.

Alex