This is the result of merging two images. I shot the Plaskett Dome on July 26, 2007. The star trails were created by using images taken from Cattle Point on August 8, 2007. I took an azimuth reading during the shoot at the DAO and used it at Cattle Point in order to reproduce similar conditions. Setting up the altitude was more difficult since there is no scale on my Manfrotto mount.

Location: DAO (foreground), Cattle Point (background).
Optics: Canon EF 17-40mm f/4L USM.
Camera: Canon 20Da on Manfrotto mount.
Exposures: Foreground- one single JPEG of 15 sec, ISO 400. Zoom-lens set at 17mm f/4.
Background- 87 light frames of 1 min, ISO 800, shot in RAW. Zoom-lens set at 17mm f/4.
Process: RAW images converted to JPEG in Canon Digital Photo Professional. Star trail created in Photoshop. Gaussian blur applied to star trail. Two images merged in Photoshop.