Captured over 4 nights, late May 2020, 4h 9m integration.
Dave
M27, Dumbbell Nebula
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Please upload large images to photo sharing sites (flickr, etc) rather than trying to upload them as forum attachments.
Please share the equipment used and if possible camera settings to help others.
Please upload large images to photo sharing sites (flickr, etc) rather than trying to upload them as forum attachments.
Please share the equipment used and if possible camera settings to help others.
Re: M27, Dumbbell Nebula
Thanks for the plug, Dave. I'm still working on the documentation.
I developed that tool to help explain why my 11.6-hour M81 was skewed toward the red. The problem is that the atmosphere attenuates blue and green wavelengths more severely than red at any given altitude above the horizon. If it were possible to capture the red and green and blue frames simultaneously, such as with an OSC camera, then this would not be an issue, but since mono camera users capture a series of red frames first then green and then blue the altitude is different for each filter. All said and done before you go to post-processing you need to analyze all the frames to get the SNR balanced across the stacks. That is what my Analyzer tool does. For my M81 the red stack had a slightly higher SNR so I removed a few red frames. For Dave's M27 he had too many red frames as well as green frames.
I developed that tool to help explain why my 11.6-hour M81 was skewed toward the red. The problem is that the atmosphere attenuates blue and green wavelengths more severely than red at any given altitude above the horizon. If it were possible to capture the red and green and blue frames simultaneously, such as with an OSC camera, then this would not be an issue, but since mono camera users capture a series of red frames first then green and then blue the altitude is different for each filter. All said and done before you go to post-processing you need to analyze all the frames to get the SNR balanced across the stacks. That is what my Analyzer tool does. For my M81 the red stack had a slightly higher SNR so I removed a few red frames. For Dave's M27 he had too many red frames as well as green frames.
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Re: M27, Dumbbell Nebula
Beautiful image- great color and sharp stars- congrats!!!
Re: M27, Dumbbell Nebula
Thanks Bruce.
Dave
Dave