the importance of polar alignment

[raymo]

I want to illustrate to newbies just how critical good PA is to the
obtaining of good images.
The attached image of IC 2602 was grabbed in the brief period
between clouds. I was taking 2.5sec subs whilst getting the focus
as good as I could in the short time available. I ran out of time, so
had no time to change the exposure. I had, due to lack of time,
just plonked the scope down facing probably within 4 or 5 degrees
of the pole, and done a 2 star align.
The point of all this, is that even with 2.5 sec exposures at the prime focus of my f5 Newt, the stars are significantly elongated. In case anyone wonders how so many stars are visible, this is a stack of 8 2.5 sec subs
at ISO3200. Magnify image to better see the elongation of stars. 175 or 200% shows it well.
raymo
P.S. Was wrong photo, have changed it.