Hydrogen alpha images are monochromatic, a single ultra narrow spectral line centered at 656.28nm.
The solar disc is brighter than the prominences. Atik camera typical exposure times are 0.001sec for the disc and 0.03sec for the prominences. However, the Atik camera failed after just 2 weeks use.
Canon camera typical exposure is 0.003sec at 800ASA. The prominences are in the red channel and the disc is in the green channel (by leakage of bright, monochromatic, red light) while the blue channel is usually discarded.
More recently, an Olympus E410 has been used for full disc views because it has the advantage of live view for focussing and adjusting the etalon, but its relative insensitivity to H-alpha light means it is not ideal. I am on the look-out for a good H-alpha camera, when my finances recover.
Colours are later added during image processing and are abitrary.
20071230 0148 Ha: |
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20080126 0129 |
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| Easter Sunday Prominences |
Solarscope Etalon technical data
Cloud sensor(Farm Cove Observatory is very close to the solar observation site)
Web site and photography: John Wattie
