Another clear night for a short while and after much buggerng about with new ED80 I ended up going back to my Sigma APO instead. Windy conditions made my available sky limited so I opted for the American Nebula again. This time I took into account white balance to compensate for the Astronomik CLS filter.

Click for larger image9x3mins, ISO800, 149mm, F4.6. Canon 450D + Astronomik CLS + Sigma APO 70-300mm.
Note for Will: Here are the links I mentioned. TIFF and Canon 450D RAW of one of the single unprocessed subs that went toward producing this image of the American Nebula. The cyan cast is caused by the Astronomik CLS filter.
14.56MB .CR2 version70MB .TIFF versionHope you have broadband!
Labels: Astronomik CLS, Astrotrac, Canon 450D, Sigma 70-300mm APO