M13 Hercules Globular Cluster
Posted: Mon May 02, 2022 2:43 pm
I just did see that Oopfan (Brian) also made a M13 posting. Here is my version from 2 nights back (plus data from 2021).
Capturing and processing globular clusters really is like a different kind of discipline in comparison to galaxies or nebulae. I used 30 second exposures and with my f/10 scope, that's right around the "switching point" where drift becomes visible but where the pixels are not "full".
And with processing it's a balancing act between not using (or almost not) noise removal because the small faint stars disappear but at the same time stretching rather aggressively to show those same stars. And of course not to blow out the core.
Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC mount
Baader IR/UV Cut filter
Optolong L-Pro filter
Zwo ASI071MC Pro camera
Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
Baader IR/UV Cut: 50 x 30sec / Gain 90 / Offset 10
Optolong L-Pro: 100 x 30sec / Gain 90 / Offset 20
Per set: 20 x darks, 50 x flats and 50 x darkflats
Stacked with DeepSkyStacker
All in 1 stack
Processed with Siril and Photoshop
Siril: Background Extraction, Histogram, Crop
Photoshop: Curves, Levels, Camera Raw Filter (blacks, white balance, shadows, color saturation, clarity, sharpening, noise reduction)
Capturing and processing globular clusters really is like a different kind of discipline in comparison to galaxies or nebulae. I used 30 second exposures and with my f/10 scope, that's right around the "switching point" where drift becomes visible but where the pixels are not "full".
And with processing it's a balancing act between not using (or almost not) noise removal because the small faint stars disappear but at the same time stretching rather aggressively to show those same stars. And of course not to blow out the core.
Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC mount
Baader IR/UV Cut filter
Optolong L-Pro filter
Zwo ASI071MC Pro camera
Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
Baader IR/UV Cut: 50 x 30sec / Gain 90 / Offset 10
Optolong L-Pro: 100 x 30sec / Gain 90 / Offset 20
Per set: 20 x darks, 50 x flats and 50 x darkflats
Stacked with DeepSkyStacker
All in 1 stack
Processed with Siril and Photoshop
Siril: Background Extraction, Histogram, Crop
Photoshop: Curves, Levels, Camera Raw Filter (blacks, white balance, shadows, color saturation, clarity, sharpening, noise reduction)