Equipment:
– Meade 70 мм quadruplet apo astrograph
– Meade LX85 mount
– Optolong L-eNhance 1.25″ clip EOS
– Canon 550Da camera.
30 frames per 120 seconds.
Calibration and stacking with DeepSkyStacker. Bicolor (RGG, only nebula).
Location: Russia, Anapa, backyard.
Single frame example (on-camera JPEG):
The source material and the result of the addition (NGC 7000 stacked.fts) are available here.
The material turned out to be very difficult due to the lack of movement during shooting – diagonal noise (“broom”) appeared in the image. More precisely, there was movement, but due to an inaccurately aligned polar axis. An attempt to combine frames only from the beginning and end of the shooting did not provide much improvement. Horizontal banding also appeared in the image. Therefore, the material went into storage until I learned how to eliminate such artifacts.
I opened the resulting addition result using Graxpert, converted the histogram (Stretch Options > 20%), saved the image (Save Stretched & Processed). First of all, you need to remove the stars from the image via StarNet++, and also save them as a separate image.
Next we work with the nebula:
– removing diagonal noise using the FixelFFT plugin.
– reduce diagonal noise via ImageJ (Process > Noise > Remove Outliers, Which Outliers – Dark).
– remove horizontal stripes using Fitswork (Processing > Background Flatten > Lines to Equal Values, value 0.63).
Next, we apply noise reduction to the nebula, add saturation, and put stars on top.