polar alignment

JY · Post by JY » Mon Jun 20, 2005 3:37 pm

Excellent explanation on drift alignment, thanks for the link

JY

ariefm71 · Post by **ariefm71** » Mon Oct 16, 2006 11:11 pm

cheap software for drift alignment using webcam: http://wcs.ruthner.at/index-en.htm

yanyewkay · Post by **yanyewkay** » Tue Mar 06, 2007 6:21 pm

sorry for digging up an old post. I was searching for how to do drift alignment.

just a quick qn.. the method recommended.. does that mean I can't do it with a red dot finder?

my scope comes only with a RDF

kingkong · Post by **kingkong** » Tue Mar 06, 2007 7:27 pm

it's not practical to use a finder for drift alignment...

the best drift alignment tutorial i find is:
http://www.petesastrophotography.com/in ... nment.html

you can practice on the drift align simulator. just make sure you set to the right type of scope you'll be using for real.
http://www.petesastrophotography.com/tu ... ngsim.html

yanyewkay · Post by **yanyewkay** » Wed Mar 07, 2007 12:39 am

that means I have to buy an illuminated recticle eyepiece? *faint* more $ to spend...

yanyewkay · Post by **yanyewkay** » Wed Mar 07, 2007 12:43 am

that means I have to buy an illuminated recticle eyepiece? *faint* more $ to spend...

EDIT: oops.. don't know why there's a duplicate post. can mods/admin help delete this?

aquillae · Post by **aquillae** » Wed Mar 07, 2007 2:08 am

yes, illuminated reticle eyepiece is a must for drift alignment.

unless you're using a webcam for drift alignment, you can use the software to display both star and a crosshair on the screen.

ariefm71 · Post by **ariefm71** » Wed Mar 07, 2007 2:37 am

yanyewkay · Post by **yanyewkay** » Wed May 09, 2007 4:11 pm

back to the same topic of polar alignment AGAIN!
can anyone explain to me what the 3rd pic is talking about? under the part "UNDERSTANDING HOW IT WORKS"
http://www.petesastrophotography.com/tu ... nment.html

also which stars do you guys choose for your polar alignment?

Post by **perseid** » Wed May 09, 2007 4:52 pm

If you have a camera that has exposure of over 2 minutes, you can do the "digital" way of alignment.

Instead of using an illuminated recticle, I use my DSLR camera to do my polar alignment.

Here is the way.

1) Attach your camera to your telescope, like you do when taking images. Focus as good as possible.

2) As with the manual alignment, place a star near the zenith in your camera field of view. Set your exposure around 200ASA (too high ASA, stars may be washed out).

The total exposure time is 2 mins and 10sec. First 10 seconds of exposure, just leave your camera and the mount drive on.

For the next 60secs, press either RA+ or RA- button with 2x sidereal speed. After 60secs, press the other way.

You should get an image such as these.

Your first image may be similar to the one on the left. As you can see, initially the star is on the left side, but after 2 minutes, the star has drifted to the right. Don't worry about which direction the star move, either N, E, S or W. Just adjust the polar axis of your mount, slightly to the east or west. Then repeat the procedure. You can stop the alignment process when you only get a straight line, and not "v" shape.

You can do the same thing for declination alignment. Just point your camera as near to the eastern or western horizon.