Posts Made By: Alex McConahay

Ron, and others--

Yes, there are still some spots available in the workshops themselves. (But they are going.) You could register on site, or to be sure you get one of the remaining spaces, goto

http://www.rivastro.org/ras_imaging_event.html

The hotel rooms at the resort sold out a while back (although there have been occasional cancellations you might get, so you can try) but there are other hotels in town. There were 19 or so RV spots left last week. And there are other campsites around, including in Anza Borrego State Park (I think the reserved campsites there are gone, but there are plenty of others.)

This is a great star party--It has pools, and showers and restaurants, and a bar, and a pretty good conference going.

And yes, John Rhodes will be there with an Ethos, I'm sure.

And yes, you can actually sit around and shoot the breeze with Jim Burnell (who co-wrote Handbook for Astronomical Image Processing) as he takes pictures under the desert skies.

Alex

I doubt you could back up the smoking dope charge. Ganja is not for the folks at Money. I would suspect they traffic in much higher and more refined substance abuse.

Alex

The other answers are correct. But you might also try using the CCD calculator from Ron Wodaski

http://www.newastro.com/newastro/book_new/camera_app.asp

Alex

I've owned both.

A motorhome is a lot easier to drive and use. You can have people sleeping and eating and such as you drive down the highway. You can drive the speed limit, and not be limited to the slower 55 mph. And you can tow a boat or something.

On the other hand, if (once you are at your destination) you want to go somewhere on a day trip, you have to nearly break camp. Of course, there are ways around this--like towing a car with your motorhome. This can be real inconvenient visiting a National Park, say, where you park the RV, and then decide to take the scenic road through the park to visit the attractions.

A motorhome is a large vehicle with an engine and lots of things to go wrong. It is not good for much else. On the other hand, a trailer takes a decent size tow vehicle, which also is not much good for other things. If you already have a tow vehicle, (like a pickup or large SUV) then it is not that big a deal.....But that is a consideration.

I think people who have tried both wind up with a motorhome in the long run.

Alex


Unless I were going

Well, it's a drive from Arizona--but you might try Nightfall:

http://www.rtmcastronomyexpo.org/nightfall.htm

Alex

F ratio is a mathematical relationship between the focal length and the aperture. Simply divide the focal length by the aperture, and the result is a "F Ratio."

Just to oversimplify:
Longer F ratios (Higher numbers like F10) are easier to make well. They are simply less demanding. They are easier to collimate. They generally give more magnification for any given aperture. The tubes will be longer (for any given design). At times so long, they will be difficult to mount.

Shorter F ratios (Lower ratios like F4) are harder to make well. They require tighter collimation and focus and show coma (an abberation where the stars away from the center have a gull wing shape instead of a pinpoint. They do have a wider field of view, though, for any given focal length.

Fact is, you are trading field of view for magnification.

Imagine the light at the primary as the base of a triangle. A short, wide triangle is a low F Ratio. A tall, narrow triangle is a high F Ratio.

As for which one to buy----tell us what you wnat to do with it.

Alex

Floyd,

I'm not familiar with PHD but most guiding programs can put out a text file or something of their corrections. You can put that into an Excel graph and actually watch your mount's error. Give it a shot if you can, and let's look at it.

Alex

You will be able to find all the objects you would need in the six. But in the eight you will be able to see more detail, and actually study them. You will upgrade from a six, and leave it behind. But an eight will be with you forever. (Not to say you won't upgrade from it, but you will keep the eight for when you want a quick look.) I just cannot see that the six is that much lighter or smaller to make it a concern.

Alex

Have you seen Richard Berry's CCD Cookbook?

Alex

What design and size of scope, what length eyepiece. It is possible you are seeing the central obstruction in a newt or SCT.

Otherwise--what is the pattern of the obscuration?

As to whether you are crazy--well, let's talk about the eyepiece.

Alex