Messier 53 -- Globular Cluster in Coma Berenices
10 May 2023, 02:30 UT, Stuart, Florida USA.
Clouds: partly cloudy
Seeing: below avg 4/10
Transparency:
Celestron CPC Deluxe 1100 HD telescope, f/10. Mallincam DS10C color camera, bin 2, 14 bit, exposure 7s, gain 5000, UV/IR cut filter, no guiding. Stacked 100 light frames with dark, flat, and bias frames.
Notes:
1. Bin 2x2 may not reveal limiting star magnitude. Try bin 3x3.
2. Next time...try lower gain, and longer exposure (but probably < 25 sec to limit star trailing) to capture the dimmest stars and produce a richer image. [Adjust to pixel size ~= 12μm (by binning or camera substitution) for this OTA to capture stars near limiting magnitude, per Thom. fowler ref. Minimize gain to increase dynamic range in images.]
Image scale: slightly oversampled -- 0.68 arcsec/px (Dawes Limit: 0.42 arcsec).
Altitude: 76°
Processing: Pre-processed and stacked in Siril with calibration frames. Final processing in Photoshop (stretch, RC-Astro NoiseXterminator, Topaz Denoise, resize).
First attempt with Siril 1.2.0, and like it better than the original version produced via DSS. Siril provided richer core, better color, and easier stretch.
Conclusions: Capturing the calibration frames was well worth the effort, and it may be possible to improve the light frames and the final image by adjusting camera settings to enable capturing more dim stars.
Messier 53 -- Globular Cluster in Coma Berenices
10 May 2023, 02:30 UT, Stuart, Florida USA.
Clouds: partly cloudy
Seeing: below avg 4/10
Transparency:
Celestron CPC Deluxe 1100 HD telescope, f/10. Mallincam DS10C color camera, bin 2, 14 bit, exposure 7s, gain 5000, UV/IR cut filter, no guiding. Stacked 100 light frames with dark, flat, and bias frames.
Notes:
1. Bin 2x2 may not reveal limiting star magnitude. Try bin 3x3.
2. Next time...try lower gain, and longer exposure (but probably < 25 sec to limit star trailing) to capture the dimmest stars and produce a richer image. [Adjust to pixel size ~= 12μm (by binning or camera substitution) for this OTA to capture stars near limiting magnitude, per Thom. fowler ref. Minimize gain to increase dynamic range in images.]
Image scale: slightly oversampled -- 0.68 arcsec/px (Dawes Limit: 0.42 arcsec).
Altitude: 76°
Processing: Pre-processed and stacked in Siril with calibration frames. Final processing in Photoshop (stretch, RC-Astro NoiseXterminator, Topaz Denoise, resize).
First attempt with Siril 1.2.0, and like it better than the original version produced via DSS. Siril provided richer core, better color, and easier stretch.
Conclusions: Capturing the calibration frames was well worth the effort, and it may be possible to improve the light frames and the final image by adjusting camera settings to enable capturing more dim stars.