Image of the day

Captured by
Douglas Rollain

Lion Nebula SH2-132 - RC71

About Astromart

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Alex McConahay

January 2, 2010 04:29 PM Forum: CCD Imaging and Processing/Solar System

ISS transits the moon

Posted By Alex McConahay
I'm about done with this phase of my life. Time to move on.

I have posted a movie on my webpage. You can see an edit of the captured video footage, and in another link a movie (7 Meg) of David, Jim, and my efforts for the evening.

The links were added at the bottom of the page, so just jump down to the bottom and click away.

http://alexastro.com/Alex%20Home%20Page/SolarS/solarsindex.html

Alex

January 12, 2010 01:33 PM Forum: ASTRONOMY

Identifying Constellations & 1st Magnitude stars

Posted By Alex McConahay
I don't consider myself particularly competent as an observer, but I could pretty much figure out about two thirds of what I am looking at on any given night. I should say that I actually learned more after I got a goto scope since I had to learn the names of the stars that I was using to build my alignment for the night.

Alex

January 14, 2010 01:40 PM Forum: Eyepieces

Widefields: Are They Worth It?

Posted By Alex McConahay
Rod,

What is "worth" has a lot to do with this question.

The Ethos, etc. provide a superior view. That is surely nice to use for most of us.

If I had to choose between it and a new sport coat and slacks, I'd go with the Ethos. If I had to choose between it and meals for my family for a month, I'd go with the meals.

Financial means radically change the definition of "worth."

Alex

January 15, 2010 01:53 PM Forum: Digital SLR AstroPhotography

Another Horse

Posted By Alex McConahay
Beautiful, and I appreciate your color treatment.

Alex

January 18, 2010 12:26 AM Forum: Beginning Astronomy?

Need help with eyepiece height

Posted By Alex McConahay
In adddition to the other advice (basically that focal ratio has as much as anything to do with it)--

THe design of the rocker box, bearings, and baseboard will also affect the eyepiece height.

The design of the tube, in combination with the size of the secondary/height of the focuser, will also have a slight effect.

Together these can make a difference of as much as a foot in eyepiece height from one set of design criteria to another.

And while we are at it, remember that you may want to optimize for just below straight up and down--very rarely do you look into "Dobson's hole" anyway. And stepping on a two step ladder, or up on a block may not be all that big a deal.

Alex

January 22, 2010 07:49 PM Forum: Off Topic Discussions

Manual 35mm SLR Camera

Posted By Alex McConahay
Sunny 16 Rule

On a sunny day, your lens aperture should be open to F16, and your shutter speed should be 1 over the ASA. And I say ASA since that is the way the Sunny 16 Rule is written. You may translate ASA into ISO to "modernize" it.

In short, on a sunny day, with ISO 400 film, take your picture at F16 and 1/400.

With that as a guide, modify your settings for oter lighting conditions.

But, if you keep the needle in the middle, you should be getting just that exposure.

Otherwise, just click away.

Alex

January 23, 2010 02:31 AM Forum: Equipment Talk

Counterbalance issues...

Posted By Alex McConahay
Any reason you cannot raise the bearings?
It is always better, if possible, to balance it without counterweights.

Alex

January 23, 2010 02:42 PM Forum: Beginning Astronomy?

Celestron 9.25 w/cg5-gt

Posted By Alex McConahay
Join the club!

No, seriously, go join a club. There will be plenty of people to help you get that thing working.

THere are a number of lists of clubs available. Just Google ' "Astronomy Club" + [Hometown]' where you substitute your hometown in the brackets. Or post here where you live.

ALex

January 23, 2010 02:45 PM Forum: AstroMart FAQ

PM list no longer updates?

Posted By Alex McConahay
Mine is fine.

Alex

January 24, 2010 12:01 AM Forum: Equipment Talk

Mount decision ?

Posted By Alex McConahay
I am assuming the "Double Yoke" is the standard Fork Mount? Am I right?

John, before trying to answer this for you, please tell us how you plan to use the scope. Imaging has different requirements than visual.

ALex

Funding Member

Sponsors


View all sponsors

Search