Polar alighning with a lazer pointer

[danielsun]

Just bought myself an EQ5 and being a dob man this polar alighning stuff is new to me .Although i have got the basic jist of it i was finding it hard to get acurate until i had a brain wave and thought of turning up an adapter sleeve that holds my lazer pointer and having it slide in the front of the polar scope hole on the mount, which should allow me to get it fairly acurate, and probably even better with a telrad.
Just wodering if anyone else has used this method of polar alighning.

[h0ughy (David)]

how will this work? You wont be able to see octans?

[danielsun]

Maybe use bino's to see were the lazer is pointing.
Would that work?

[danielsun]

Or, find sigma octans (or is it beta?) which is able with the naked eye and just go off to the side, should be able to get close-ish as a starting point.
I dont know if just have a cheap polar scope because i can barely see anything though it!

[gbeal]

Along a similar line, try this posting on NZ Astronomers
http://groups.yahoo.com/group/nzastr...ssage/8114?l=1
It is by Dave Moorehouse, and is similar in concept to what your posting is about.

[[1ponders] (Paul)]

Why not just drift align Daniel

If you are going to image then you might as well get used to it 'cos polar scope alignment isn't reeeally accurate enough for that. Sure you can auto-guide but the less adjustments your mount has to make the better.

It's a bit like collimating, once you know how it's easy and for viewing only nights if you mark your leg spots on the ground you won't have to keep doing it. I only re-drift if I'm imaging. Plonk and play is usually close enough even using the AN.

[rogerg (Roger)]

Originally Posted by danielsun

Just bought myself an EQ5 and being a dob man this polar alighning stuff is new to me .Although i have got the basic jist of it i was finding it hard to get acurate until i had a brain wave and thought of turning up an adapter sleeve that holds my lazer pointer and having it slide in the front of the polar scope hole on the mount, which should allow me to get it fairly acurate, and probably even better with a telrad.
Just wodering if anyone else has used this method of polar alighning.

This is exactly what I bought my green laser pointer for a couple of years back. I put the scope pointing where it thinks the SCP is, put the laser pointer on the scope such that it's pointing exactly in line with the RA axis, then adjust the Alt & Az until the green line (visible in the eyepiece) point exactly at the SCP.

Very easy to get a surprisingly accurate polar alignment - litterally 5 minutes and possible without the scope even turned on. At about 80x with the eyepiece I use, I can see exactly where Sigma Oct and other stars are to know exactly where the green should be pointing.

The only thing it relies upon is your mount having somewhere you can rest the laser pointer that is exactly (or as close as possible you can get) in aligment with your RA axis, and you knowing where the SCP is.

Once I've aligned this way, I start taking images and correct throughout the night as appropriate - I take an image that happens to be at the meridian for 40 minutes, correct for the drift, do the same for an image at the east horizon. I can do 5 minute DSLR exposures no problem with the initial alignment, so I figure I might as well use the time I'm doing the drift fine tuning to take photo's.

Roger.

[pluck]

This is actually not a bad idea - how often do you find yourself plonking your eq(x) down and trying to approximate its azimuth orientation (especially on unfamiliar ground)? I wouldn't be surprised to find a vendor doing this in the not too distant future. The possible problems ? - obstructions (e.g. trees etc.) and of course laser danger.

Otherwise, good one !

P.

[danielsun]

So maybe not such a crazy idea after all.
Thanks everyone for yor feedback.