A filter such as a dual band Oxygen III (OIII) and H-alpha filter inserted along the optical train lets the light from the nebula (and the stars) pass through, but block out everything else, particularly light pollution. This image was taken in Bacoor, Cavite in July 2021, with an ASI 533 cooled astronomy camera and a 50 mm f/4 Tamron lens (at 210 mm focal length), with 27 frames of 240 seconds sub-exposure, for a total of 1.8 hours of exposure, tracked and guided using a DIY tracker. Only light and flat frames were used in this image, no darks and bias frames. This image was stacked and processed in SIRIL.
For a complete list of astrophoto images, click here.
Night Sky in Focus | Astronomy and Amateur Radio © Anthony Urbano | Manila, Philippines