13Nov/110
Almost perfect Polar alignment
When using an autoguider, there is no need to start with an accurate polar aligment. In general I strive for a polar aligment that leads to a DEC drift of less than 10"/min.
Yesterday, during full moon, I practised my polar aligment method. The classic drift method but using a webcam behind my 550mm refractor increases accuracy even more.
After the polar aligment which took me 30-60 min, the resulting DEC drift was really small. I did a superlong DEC drift measurement of more than 8hours, while sleeping. The total DEC drift was 80", about 0.25"/min. Useless, as RA guiding error caused by periodic error is close to 40" in 10min. But fun nonetheless.