Posts Made By: Alex McConahay

April 7, 2012 06:12 PM Forum: Equipment Talk

More backfocus please

Posted By Alex McConahay

I don't think I quite understand--(I get confused easily and I cannot remember if Backfocus is intravel or outtravel):

As you are moving your focuser out, do you run out movement before your star comes to focus?

Alex

April 11, 2012 10:38 PM Forum: Equipment Talk

More backfocus please

Posted By Alex McConahay

Richard,

Before you go adding optics, relay lenses, and all that--maybe you need to consider just what all you have in the train that is pushing the sensor so far back. These scopes are made with ten inches of backfocus. That is a lot. What all do you have back there? Could something be removed, or coud you substitute a thinner version of it?

Alex

April 22, 2012 08:10 PM Forum: Telescope Making

Mirror Figuring Question

Posted By Alex McConahay

North Carolina is too far away to invite you to bring it over (To California) for a test.

It is hard to say what is happening on the mirror. It may be a difference in temperature from one reading to the next. It may be a slight difference in your interpertation (or non-repeatability of your technique). Are you dealing with an astigmatism, or are you referring to a whole mirror test here? What software do you use to reduce your Foucault data to give you your results. The program I am most familiar with lets you put in three sets of readings and average them out. Unless you are pretty good, and your tester is pretty good, it is easy to get slight variations between tests.

I do know that a mirror is never done. You just eventually have to pry it from the cold, dead hands of the optician and put it in a telescope eventually. The ATM'er will want to continue to tweak that last little bit of perfection, while the observer just wants to look through the thing.

Alex

May 1, 2012 01:40 PM Forum: Mounts

Remember the first time you heard the word Hyundai

Posted By Alex McConahay

Certainly look good. Notice no periodic error rating.

Alex

May 2, 2012 09:29 PM Forum: Off Topic Discussions

Decisions Decisions.......

Posted By Alex McConahay

It is a busy time.....

The Sunday before RTMC is an annular eclipse--It will have full annularity about four or five hours away from Big Bear. Just a week after RTMC will have the Transit of Venus (of course tht is visible from all over)... Palomar is quite a place to see if you have not seen it. However, there is no more than a few hours of stuff to visit, even if you have some ins.

If you are into science with your telescope, you will want to go to Society for Astronomical Sciences in Big Bear (which may be your original conference), or into astroimaging, the Hap Griffin workshop at RTMC would be of interest.

And if you are in Southern California, remember it is also the home of Mt. Wilson--another daytrip from Big Bear.

Alex

May 12, 2012 05:15 PM Forum: CCD Imaging and Processing/Deep Sky

M95 Processing Question

Posted By Alex McConahay

Over and above reprocessing from the get go with cleaner darks or flats (depending on where the problem came from) you can:

Use the clone tool to past clean pixels over the black pixels.
Use the healing band aid to replace the black pixels.

You also have some blooming that needs attention and a gradient that gets lighter at the top right.

Don't get me wrong--this is a good pic. Just that nothing is ever perfect.
Alex

May 12, 2012 10:22 PM Forum: Off Topic Discussions

Oil Prices Down/Calif Gas Prices Way Up

Posted By Alex McConahay

The maintenance consists, in large part, of switching over from winter formulations to summer formulations. So, yes, there is a lot at the same time.

Alex

May 17, 2012 05:47 AM Forum: Off Topic Discussions

Tell me more about gender equality?

Posted By Alex McConahay

What part of it do you think is hogwash? That a girl wanted to play baseball, or that some team refused to play against her?

Alex

May 17, 2012 09:09 PM Forum: Solar System Observing

Eclipse progression

Posted By Alex McConahay

I believe you have the order correct----however, I do not believe you will have the Diamond ring, etc....phenomenom at all. That is my guess. Not an educated one, just my guess.

This eclipse will only be 93.499 % diameter, and 87.421% surface (from where I will be). I do not believe this will dim the sun enough let the edge phenomenom show through.

I have asked in various places, and am told that one must use a solar filter throughout the annularity. This is not a total eclipse. We will not get the corona, or the Beads, etc. No earthshine off the moon.

We'll know SUnday if I am right.

Alex

May 22, 2012 10:29 PM Forum: CCD Imaging and Processing/Deep Sky

Hap Griffin Workshop at RTMC

Posted By Alex McConahay

I am about to drive the trailer out the driveway on the way to RTMC and I get two requests----Is there still room in the Hap Griffin Workshop?????

Yes, you can still register and attend, but the registration website is closed down. So, please check in at the Riverside Astronomical Society booth, or see me personally when you get to Camp Oakes.

Alex