This image of the Crescent Nebula NGC6888 was taken through a ten inch reflector using PHD
auto-guiding. Five minute sub frames and matching dark frames were used.
The exposure times were five minutes for each RGB colour filter , thirty minutes for Olll and
sixty minutes for H-alpha. The Crescent nebula lies in the constellation of Cygnus at a
distance of about 5,000 light years: