M27 Dumbbell Nebula, Vixen 81s + Altair 183C
Posted: Sun Jun 30, 2019 12:41 am
Living at 53°N, this image was captured when there was no astronomical darkness. The 1h 40m capture of lights took place between 00:40 and 02:20 on 29th June 2019. High res image here https://www.astrobin.com/full/412451/0/.
Equipment: Celestron AVX, Vixen 81s, Altair 183C, Altair 1.0x flattener.
Preparation: 2 alignment + 4 calibration stars + All Star Polar Align. A Bahtinov Mask was used for focus.
Software: SharpCap, FITS Liberator, SiriL, GIMP.
Capture: RAW12, Black Level 30, Gain 200, Exposure 60s, unguided. Bortle 6 site.
Data: lights 100x60s, darks 60, bias 100, flats 100.
Processing: SiriL was used to calibrate, register and stack (best 90% based on FWHM) the frames and carry out crop, background extraction, colour calibration, colour saturation, remove green noise & histogram transformation. Minor edits and colour balance carried out in GIMP.
FITS Liberator was used to check that a bias frame at gain 200 & black level setting of 30 had a centralised histogram plus test frames to establish the exposure setting gave a reasonable histogram for capture.
Dave
Equipment: Celestron AVX, Vixen 81s, Altair 183C, Altair 1.0x flattener.
Preparation: 2 alignment + 4 calibration stars + All Star Polar Align. A Bahtinov Mask was used for focus.
Software: SharpCap, FITS Liberator, SiriL, GIMP.
Capture: RAW12, Black Level 30, Gain 200, Exposure 60s, unguided. Bortle 6 site.
Data: lights 100x60s, darks 60, bias 100, flats 100.
Processing: SiriL was used to calibrate, register and stack (best 90% based on FWHM) the frames and carry out crop, background extraction, colour calibration, colour saturation, remove green noise & histogram transformation. Minor edits and colour balance carried out in GIMP.
FITS Liberator was used to check that a bias frame at gain 200 & black level setting of 30 had a centralised histogram plus test frames to establish the exposure setting gave a reasonable histogram for capture.
Dave