Posts Made By: Alex McConahay

Steve,

Could you be a bit more specific. I can't see reference to a cure for TDE in that article......Maybe I'm not looking hard enough. I do see a reference to the sandpaper for beveling.

Alex

I regularly have mine pushed one stop. My buddies (who really know what they are doing, and tell me how to do it--I just follow their lead) say that grain is no problem.

I must admit I have not done comparisons, though.

Alex

David,
I would say that your laser collimator needs to be collimated, except that your cheshire is doing the same thing.

Here are a couple of things you can try.

Find a kitchen counter or a floor or something that is very flat. Turn the laser on, set it on the counter or floor, and point it against a nearby wall. Roll your collimator along the counter or floor. Does the beam trace a perfectly flat line against the wall? If yes, it is collimated....If no.....collimate it.

Check your slop in the focuser. Can you change where your laser point hits by merrely pushing on the collimater?

Rack your focuser in and out. Does this change where the point hits?

Alex

David,

I cannot quite figure out what you are asking.

In general, most of us say that if you divide the focal length (in mm) of the imaging optic (telescope)by 50, you will get the "power" of the scope for a 35 mm camera. A 900 mm lens gives you approximately 18 power. This 50 is the best match in perspective of the normal one power that the eye sees. That of course is why a 50 mm lens is considered "normal" However, the image size on film is not necessarily related to the size that your eye would see, and of course, the amount you blow up the print, or project it on the wall, and then how far from the wall you are sitting or how far you hold the print from your eye will determine its relative magnification to your eye. In short--the term "magnification" does not really apply.

However--are you asking what size is the image of a full moon on 35 mm film using a 900 mm lens? You will get an 8.2 mm image.

Does that answer your question?

Alex

Larry,

Think it out just a litle. The administration, acting as bully, picked Iraq as it's victim. As in most schoolyard bullying brawls, it chose a good one to pick on. Iraq's leadership is despicable.

Then the administration worked itself into a lather, using a lot of rumor, and then worked the rest of the country up, too. Luckily, a bunch of other countries (not just France) have asked real questions and kept some cool. But you sound like you are losing yours. Get out of your battle gear, and maintain your cool. People will die if you (and a bunch of other people) do not think this out a little better.

Alex

Tom,

I am from Southern California, but I do not know of any public observatory open out that way.

Palomar is not very close to Palm Springs (I'd guess a couple of hours by car). I should guess there would be a few campers set up in the area around Palomar (the "Observatory" campground, a couple of miles from the observatory and having nothing (except proximity and name)to do with the observatory would probably be your best bet).

A second alternative, about an hour away from Palm Springs, (on the side opposite to Palomar) is Joshua Tree National Park. In the Cottonwood campground you can usually find space this time of year. (The other campgrounds are full of rock climbers and it is their season right now.) Cottonwood is close to the SOuthern Entrance (an hour east of Palm Springs on I-10) and not at all near the northern entrances where most people go.

Try the Web site for the Astronomical Society of the Desert. (Do a Google Search)

Finally, it is not a Star Party weekend for the Riverside Astronomical Society, and I do not know if anybody will be on site--but check out Rivastro.org and go to the information about the Landers Observing Site. Somebody is often there the weekend before the new moon (although there is nothing official). And even if they are not there, you can set up anywhere you like and are always welcome.

P.S. If you are in the mood for observatory museum looking--you might want to try Mt. Wilson. Also about two (maybe three hours) from Palm Springs--and a much better tour than the 200 inch.

Alex

Jeff,

Telescope control and guiding do not take much. $200 will set you up fine with a used one. SOmething with a Pentium 150 or better. Small screen is no problem. USB, CD, etc would be good to have.

If you plan to process your images with the same computer, however, you may want to get more computer just in the interest of time and frustration. However, processing is best left to home computers on rainy nights.

Alex

William,

I hate the idea of the green laser. I go to a lot of trouble to find a dark sky, and have somebody who thinks his observing program is more important flashing a big green light into the night?????

(However, I like the idea of using a cheap goto as a sky atlas.)

Alex

Stuart,

My first choice would be an 8-24 zoom for that scope. Next would be a good barlow (or powermate).

Considering what the Ranger is, a small, portable, well made, rugged, relatively small aperture, short focal length telescope with wonderful optics--I think you have what you need with that zoom and powermate. I have a TV 8-24, and with it, I can go everywhere from 20 to 60 power. The barlow runs that to 120, or 150 with the powermate--right about at it's limit.

You bought that scope for it's ability to go anywhere with what is packed into it's little soft bag--DOn't defeat that putpose by bringing a bunch of other things.

I might consider a 32 plossl, or a quickfinder one power finder to use as a finder.

That is my two cents.

Alex

Bill,

Please explain how you came to your conclusions. It sounds like you know what you are talking about.

In my novice view, there are two problems with the picture. Polar alignment is not one of the problems. If it were polar alignment, something would be dead on--and everything else would rotate around it.

As for the spikes, I agree it may be some kind of reflection, but I would guess it is simply the initial shake of the the camera--the brightest things can be exposed and leave their mark on the film, and then as the camera settles, they are still making their mark on the film--but in a different place. And they settle, burn out the exposure, while the rest of the dimmer stars leave their trails. The dim stars are not bright enough to show in this initial streak.

The other error I see is that the right ascension speed is not dead on. It seems like the mount did not follow exactly like it should. It is probably not periodic error, (but just may be) because it does not come back to where it should be--it just progressively moves thorugh the exposure.

Alex