Super widefield of M52, Bubble Nebula and Nova Cas 2021


A super widefield astrophoto I took in a bright & short moonless July night (2021). This is just 12 mins of unguided data! I used a reduced FSQ85-ED and a D180A. Can you spot the bright supernova Nova Cas 2021 below the star cluster M52? It was really bright that night and I couldn't resist and after the short imaging session I bought out my 100mm fluorite refractor and my widest 40mm eyepiece to observe it. The seeing was phenomenal that night.

Capturing the Light

As summer nights, here in UK, are bright and short my FSQ-85ED was equipped with its dedicated reducer making it a f/3.8 astrograph. No guiding was used as the encoders of the CEM25EC mount can handle the 3 mins exposures I used perfectly fine.

Processing Details


  • ImageCalibration

  • Debayer

  • StarAllignment

  • DynamicCrop

  • ScreenTransferFunction

  • HistogramTransformation

  • BackgroundNeutralization

  • ColorCalibration

  • MultiscaleLinearTransform

  • CurvesTransformations


  • Initial post processing


  • Further post processing

Tech Card

Date / Location

16th July 2021, Warwickshire, GMT+0, United Kingdom, TEMP: 20C, Bortle Class 4 ~SGM: 21.20 mag./arc sec2


Camera: Nikon D810A

Imaging Telescope: Takahashi FSQ-85ED

Correcting Lens: Takahashi Reducer-QE 0.73x (composite focal length at 328mm and focal ratio at f/3.8)

Mount: iOptron CEM25EC

Image Quality

14 bit RAW (NEF)

Exposure time per image / number of composities and sensitivity

ISO 1250, 4 x 180" subs

Total Integration Time


Calibration Frames

16 Darks, 16 Bias, 24 Flats


PixInsight 1.8.8-8