Posts Made By: Alex McConahay

I've posted this before several times, but it is one of my favorite photos of Mauna Kea.

Watch out for the volcano!

Alex

Ben,

It is already being done--not that you should not do it, but you could probably learn from those who do.

For instance, the software is already written, and the prices are already determined, and imaging does not require 40 inches. And if you had a 40 incher, how would you differ from a big university program?

good luck, though.

Alex

I think that is why I only fight this issue when I get really disgusted by the difference between the two monitors?

What should I set it to in order to get it to look good on whatever monitor I use? Or you use? Or the video projector down at the Astronomy Club when I do a presentation?

After all, I see the difference between my two monitors--How do I know what it is going to look like on yours? It is not that I just want it to look good here--I want it to look good on your monitor also? Or whatever monitor is looking at it out on the web.

Are you saying I should set up for Adobe SRGB?

And as far as matching my two monitors--would it not be easier to put them next to each other?

Alex

I was out at the club Observing area this weekend, and Friday got clouded out. SO the group of us there went through the 2006 Astronomical Calendar and used the Conjunction Finder in the Sky, and answered my question.

Our list came down to:
We, of course, will be in Egypt for the Eclipse.
Then the Transit of Mercury
Then the Saturn/Venus COnjunction
After that we just kinda argued about the various other little things.

Thanks, though for all your input.....It appears you all got what we got.

Alex

Thanks for the compliments--

Since it is unguided, explain how this is done, many short "clicks"

It is a combination of things that allow me to take the photo unguided. (By the way--and forgive me if I am saying what you already know--it was tracked, just not guided. "Tracking" follows the stars, but little imperfections mean that no tracking is perfect. "Guiding" helps one correct what mistakes are made by the "tracking"
mount.)

In the first place, if you really blow it up to full size you can see that the stars are not exactly round. SO, simply sizing down helps.

Secondly, I am using relatively short focal length. (700 mm I think) Therefore, the demands are not as great as they would be in a longer focal length with more magnification.

Next, I did have a good polar alignment on a solid pier. (However, I did not do a drift alignment, I just set up and used the polar alignment scope--which on the Losmandy is very good.) I also had a good balance, and the mount was running well. The G11 is a good mount.

But mostly, you are right, the longest exposure was 90 seconds, and there was not enough time to have real obvious drift. As you will note from the original posting, the photo was a composite of some 36 exposures, with the longest at 90 seconds.

It should be noted that the final composite would have been easier to make had I guided. There was some drift from one exposure to the next. It took more than an hour to gather all the exposures, and in that time, the whole setup had drifted more than fifty pixels--a bit too much for the software to do the aligning. So, I had to align by eyeball instead.

Had I been guiding, the photo would have been better, but I could not find a guidestar for the ST-4 to work with. I think the ST-4 was acting up and giving me spurious readings. Since the scope was tracking well anyway, and I was going for short exposures, I just figured I'd capture what I could without guiding.

Alex

I use 30 pounds with my Losmandy G-11 and 10 inch Meade Starfinder. And that is marginal.

I would not even pretend to use my CG-5 for the 10.

Will your mirror cell accommodate the weird contortions a German Equatorial mount goes through?

Alex

While you guys were arguing, I gave the International Sun Registry $35, so you know what you can call it from now on.

Alex

Barlow next, and then an even longer (than 25)for wider views--(although watch out you don't go too long so you don't get the black spot). Save up for wider apparent field of view in future eyepeices.

It is pretty easy to overpower a scope when you already have a 10 mm eyepiece. The next shortest starts to give you too much magnification. Reember, you are looking for detail and not size.

Alex

Try O-III, making sure that is an Oh, and not a Zero.

I found 2 of them just now at Anacortes.

They are "Narrow Band" Filters. This means they let through only a narrow band of light. Out of the whole spectrum of electromagnetic energy that may be available, they let in only one small part. This happens to be a part that is particularly strong in some types of objects. (I forget which). The light is strong in these objects because it is the color of light emitted by doubly ionized Oxygen--which makes up that particular type of object.

Since all light is diminished except that color of light, the contrast is increased, and the object shows up better.

Alex

Look up the Columbus club that meets at Perkins Observatory. I had the opportunity to see a Saturn Opposition with them a few winters ago......Nice folk.

Alex