question on guiding

What is exactly meant by "guiding" and "unguiding" an exposure?


Mauricio
http://www.geocities.com/carimau

Hi Mauricio,

"Guiding" means controling the motion of the mount, either visually or by CCD autoguiding, to ensure that the scope tracks the sky perfectly.

"Unguided" means just letting the mount drive the scope without checking how well it tracks.

No drive system will track the sky perfectly. There are always some errors due to slight imperfections in the drive gears, inaccuracies in the polar alignment, mount axies not at right angles to each other, just to name a few.

For this reason, most people use some form of guiding when taking long exposures through a telescope.

Hope this helps,

Maurice