photo:telescope_alignment
telescope polar alignment and balancing
Why do we need to do this?
a nicely aligned telescope allows the equatorial mount to track the motion of the stars accurately which makes viewing easier and allows for much better quality astrophotos.
although one could use guiding software to correct for alignment errors in long photographs, alignment error will result in field rotation whereby the stars in the outer parts of the image will develop a curved track.
Initial approximate polar alignment:
ensure your finder scope is in alignment with your telescope by locating a bright star in the telescope and then align the finder scope.
aim the equatorial mount at the celestial pole relevant for your hemisphere - in the Northern Hemisphere, aim for Polaris, in the South you have to guess based on the orientation of the Southern Cross (Crux) and Achenar +/- the Pointers (alpha & beta Centauri).
ensure the base of your equatorial mount is LEVEL
ensure the mount is set for YOUR latitude
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then use one of the more precise alignment methods to fine tune it.
for Melbourne, Australia
3 star alignment:
Drift alignment method:
preferably need an illuminated reticle eyepiece to assist in determining direction of drift and align the cross-hairs N-S and E-W;
essentially first step is to adjust the mount's azimuth until an equatorial star at the meridian stays bisected by an reticle line for 5 minutes
then repeat and adjust the mount's altitude until an equatorial star 20deg above the East horizon stays bisected by a line for 5 minutes.
mnemonic for the Nth hemisphere using meridian & East horizon stars: S-E-L ie. if star drifts South mount is too East &/or too Low
see an online video of how to do polar drift alignment:
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Clay's Kochab's clock method:
photo/telescope_alignment.txt · Last modified: 2013/05/18 10:47 by gary1