The Blue Flash Nebula in Delphinus


This image uses OIII data collected in 2015 for the nebula, and OSC RGB data collected in 2010 for the stars. The OIII data was colorized to blue in PixInsight and merged with the RGB OSC data in Photoshop.



Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27. PEC on.
Cameras: SXVR-H694 (OIII data); QHY8 (OSC RGB data)
Exposure: Total exposure time 8.3 hours version; 22 x 20 mins OIII plus 12 x 5 mins RGB OSC. All bin 1x1.
Filters: Astrodon 3nm OIII
Date: Data was collected over 4 nights in June and July 2015 (OIII data), plus 1 night in July 2010 (OSC RGB data).
Imaging automation and capture: Sequence Generator Pro

Guiding Hardware: ASI120MM, Celestron off axis guider. Guiding scale 0.92 arcsec/pixel. 1 second guide exposures.
Focusing: Rigel Systems GCUSB/nStep on stock C11 focuser
Guiding Software: PHD2. Aggressiveness 80, Hysteresis 0, Minimum Move 0.7, Max RA 1000, Max Dec 600. Guiding binned with WDM connection. Dec set to hysteresis. Dithering set to Extreme with Settle < 1.2.
Guiding performance: FWHM of subs about 1.2 arc seconds, RMS in PHD about 0.7 arcsecs.
Light pollution: Bortle 8 (white zone, NELM about mag 4.5)
Image scale at capture: 0.6 arcsecs/pixel = f/5.7
Scale of presentation: 0.6 arcsecs/pixel
Processing: Bias, darks, and flats. OIII data stacked and processed with PixInsight, with a few minor modifications in Photoshop. RGB OSC data stacked in DeepSkyStacker and processed in Photoshop. Data merge in Photoshop.