Study - Ha on Monochrome vs One-Shot Color
I have taken shots of the same target under the same exposure time. We can directly compare the resolution loss of using only the Red channel of a OSC camera vs a monochrome.
Cameras: SBIG STL-11000M & Starlight Xpress M25C
Filter: Astronomik 6nm Ha
Scope: TeleVue NP127is
Mount: Paramount ME
Exposure Time: A single 15 minute shot each.
Location: My backyard in Goodyear, AZ
CCDStack Processing:
Debayer of Red channel only of OSC FITs image.
Dark applied to the SBIG shot. No flats.
Registration of the two images
DDP scale
No sharpening was applied
Photoshop was used to create the animated GIF images at various zoom levels.
Hydrogen Alpha shots can be done using OSC, but these examples show how much detail is truly lost. If you are happy with cutting your resolution down to 50%, the detail is comparable. Conclusion is that nothing beats a monochrome camera when it comes to under-sampled narrowband imaging.
The slight curvature issues are due to using a field flattener on the STL image and the focal reducer on the M25C image.
Date: 12/08/2008
Size: 3 items