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RICHARD COFER

VdB 141 Ghost Nebula

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Posts Made By: Alex McConahay

March 16, 2010 12:14 PM Forum: CCD Imaging and Processing/Deep Sky

First image with my Ovision modded G11

Posted By Alex McConahay
Good pic.

I estimate my Ovision improvement has cut my PE substantially, (maybe in half, from 5 to 2.5 arc seconds). I did the test last night, but did not have the right number for my scope's focal length in the calculations. So, I have to re-do them.

Alex

March 18, 2010 04:35 AM Forum: CCD Imaging and Processing/Deep Sky

East to West drift while guiding?

Posted By Alex McConahay
This has been mystifying me for a while.....

Possible polar misalignment is showing up as east-west drift.

Possible that your guider is not actually guiding between exposures while the main camera is downloading.

Flexure.

If you get a real answer, I'd like to know.

Alex

March 19, 2010 04:41 AM Forum: CCD Imaging and Processing/Deep Sky

East to West drift while guiding?

Posted By Alex McConahay
You know, an awful lot of the things we are mentioning (besides flexure) are darn good explanations for things moving around. The key to the issue is that the autoguider is not correcting them!

If it were the wrong divisor, the autoguider would have simply sent signals to "catch up" or "Slow down" and it would not be noticeable.

Same thing if it were polar alignment. (I still think there is something that makes sense--a mount out of alignment will show N-S we know--but an AUTOGUIDED mount may also drift a bit---but that is for another thread.) The autoguider would have corrected for it by speeding/slowing the drive.

It must be flexure.

I know I cured my problem (of the same type) when I went OAG with my 9.25.


Alex

March 21, 2010 02:01 PM Forum: Digital SLR AstroPhotography

M 46

Posted By Alex McConahay
Planetary looks bigger than I expected.
Nice job.
Alex

March 22, 2010 04:03 AM Forum: CCD Imaging and Processing/Deep Sky

First image with my Ovision modded G11

Posted By Alex McConahay
Here is the Ovision results for my home observatory G11:

Alex


March 22, 2010 04:05 AM Forum: CCD Imaging and Processing/Deep Sky

First image with my Ovision modded G11

Posted By Alex McConahay
Here are the Ovision results for my Desert mount.
(be aware that the Losmandy run was longer--so has more peaks and valleys (more worm cycles).

Alex


March 25, 2010 04:45 PM Forum: Digital SLR AstroPhotography

Digitized images from old magazines

Posted By Alex McConahay
I get it that you are trying to find some old photos of M109 to see how the work in the olden days compares to your recently taken photo.

May I suggest a library, where you might find an old book on the heavens. A number of high school libraries, college libraries, etc. might work. In addition, your local club probably has a guy who has been collecting all his old magazines for thirty or forty years. I even keep old Meade Catalogues from when I first bought equipment.

FInally, compare your work to the Palomar Sky Survey (available in various places, I understand) and other work that was done in the middle of the last century.

Alex

March 27, 2010 05:41 AM Forum: Digital SLR AstroPhotography

The best way to print...

Posted By Alex McConahay
Send it to your local Walmart, Costco, etc. and have them do it.

Alex

April 8, 2010 01:32 AM Forum: Deep Sky Observing

Marking up a star atlas

Posted By Alex McConahay
I spent a very constructive weekend one time marking a brand new copy of Sky Atlas 2000 with the constellation stick figure patterns. It has proven quite worthwhile. I tried once using post-its, but they did not last.

You might find it valuable to run off a copy of a sky chart out of a planetarium program, and do your marking on that. That way if your interests change, you do not have a bunch of distracting markings.

Alex

April 12, 2010 01:27 PM Forum: Deep Sky Observing

Dark skies VS Aperture???

Posted By Alex McConahay
In the last couple of months, I read (Astronomy Technology Today, or Astrophoto Insight--or maybe just off the web) that an eight inch under dark skies matches a thirteen under brighter skies. And this was an actual test, with formulae and calculations, and all that.

I should say that I have forgotten the details. The part I remember for sure is that dark skies win. Easily.

Alex

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