half-sized image (925 x 610) full-sized image (1850 x 1219)
The California Nebula is a large, dim spread of ionized hydrogen gas in Taurus. Its apparent size is nearly the same as the full moon, and it is difficult to see even under dark skies. An H-alpa filter and long exposure brings out the details of this wispy nebula in all its glory.
This image is a demonstration of both old and new techniques -- the luminance frame is a mosaic of two images made with my Takahashi FS60C, CCD camera and an H-alpha filter, each of the two mosaic panes being 120 minutes of exposure. Those two images, when combined, produced a high-contrast black and white image. The color for the image came from a wider-field film exposure done nearly two years before, with a TV-85 refractor and Kodak Elite Chrome 200 film. The two images were different sizes and orientations, and it took considerable resizing, alignment, and processing to bring the two together for this final view. But it was worth it!
Image details:
Luminance:
Takahashi FS60-C at f/4.4 (with flattener/reducer for FS78)
StarlightXpress HX916 CCD Camera
Astro-Physics AP900GTO German Equatorial Mount
SBIG CFW-8A Color Filter Wheel
Two images, each 120 minutes (12 10-minute images stacked) through a Shuler H-Alpha filter
Taken November 2003 from my backyard in Escondido, California
Color:
TeleVue TV-85 refractor at f/5.6 with field flattener
Kodak Elite Chrome 200 film
Losmandy G-11 German Equatorial Mount
SBIG ST-4 autoguider
45 minute single exposure
Taken October 2001 from Lake San Antonio, California (CalStar star party)
Image capture and sequencing was done with MaximDL/CCD, sub-frames were Sigma combined with Russ Croman's Sigma plugin for MaximDL/CCD, and the final LRGB layering, mosaic assembly, and image adjustments were done in PhotoShop 7.0.