A clear evening sky gave me the opportunity tonight to see planet Venus floating right below the beautiful naked-eye star cluster, the Pleiades (M45). The combination was beautiful through my binoculars, just before 8:30 PM EDT. I decided to make a quick try at recording the scene with my camera and 400mm telephoto lens mounted on a tripod. The problem, of course, is that an exposure of any decent length will cause the stars to form curved lines as they appear to move through the sky. Even my brief five-second exposure was no different… it looked great in the camera’s built-in LCD preview panel but pretty sad on the big computer screen. So I used a bit of crude Photoshop work to round out the stars. The result won’t make the pages of Astronomy or Sky & Telescope magazines but it’s not too bad and saved the shot. This, and a very intriguing result from the nearby Orion Nebula (M42), makes me eager to get out on another clear night and spend some time with the camera mated to a tracking mount or piggybacked on a telescope!
The Photoshop work, by the way, was a duplicate layer used with “blending mode” set to “Darken” and then used as an offset filter. The offset filter is nudged around until the best combination of masking and brightness is found. I found the process described in a forum discussion on Cloudynights.com.