The article states that this is the most detailed shot of the Ring Planetary Nebula ever taken from Earth:
"This photograph combines data obtained through six different filters. Most of the data come from the 1.23 meter Zeiss reflector of Calar Alto Observatory, used in the official time of the Andalusian Network for Technological and Scientific Public Outreach (RECTA), together with the Documentary School of Astrophotograpy (DSA). The images were obtained with different integration times through narrow-band filters centered on the emission lines H-alpha and O-III, until completing 18 hours of exposure time as a whole. These data were complemented with wide-band images (filters Johnson B, V and R) obtained with the 3.5 meter Zeiss telescope of Calar Alto, equipped with the camera LAICA, with a total integration time of 3 hours, under poor weather conditions. Also, the image contains 45 minutes of archival infra-red observations performed with the same telescope and the infrared camera Omega 2000, centered on the emission line of molecular hydrogen (2.12 micrometers), that helps to better define the wavefronts in the external, faint halo of the nebula. The narrow-band images were combined with the wide-band ones coding them as three different color hues: cyan for O-III, red for H-alpha (that, combined with H-beta, gives a violet color as a result), and red for molecular hydrogen. The data were processed by Vicent Peris, Jack Harvey, Steve Mazlin and José Luis Lamadrid with the program PixInsight. The image covers 10 by 11 arcminutes on the sky. Celestial north is up, celestial east is left."
I've observed this visually through an 8" telescope. It was a small oval translucent hollow stone in the sky.