6670 x 4460 px | 56,5 x 37,8 cm | 22,2 x 14,9 inches | 300dpi
Data acquisizione:
27 luglio 2023
Altre informazioni:
This is a portrait of the constellation of Cygnus the Swan, with the extensive patches of red hydrogen gas that permeate this area of the Milky Way emphasized. The field is oriented along the Milky Way. Deneb is the bright star at left. Below it is the North America Nebula, NGC 7000. To the right of Deneb is the Gamma Cygni complex, IC 1318. At bottom are the arcs of the Veil Nebula, NGC 6960 and NGC 6992-5. The nebula at far right middle is NGC 6820 in Vulpecula. Much of the other nebulosity here is numbered in the Sharpless catalogue. The dark region to the lower right of Deneb is the Northern Coal Sack. The bright area along the "neck" of Cygnus is the Cygnus Starcloud. This is a blend of exposures taken in "normal" broadband light (though affected by dew on the lens) and exposures taken in red H-alpha light, to bring out the nebulosity. This is a stack of only 4 x 3-minutes through an URTH Night filter to cut sky glow and bring out nebulas somewhat, plus a stack of 15 x 3-minutes with a 12nm Astronomics Hydrogen-Alpha clip-in filter, all with the Canon RF28-70mm lens wide open at f/2 and at 50mm, and the filter-modified Canon R camera, at ISO 400 for the broadband images and ISO 3200 for the H-a images, the latter set taken as the first quarter Moon was setting. The camera was on the Astro-Physics Mach 1 mount. Unfortunately, dew formed on the filter for the broadband images taken after the H-a set, allowing only 4 to be used, and most were dew-struck. But that added the star glows for "artistic" effect, for better or worse! The H-a images were converted to monochrome B&W and blended in with a Lighten blend mode with just the R channel on, and with Blend If and Fill Opacity controls to affect the degree of blending and to prevent the nebulas from becoming too monochrome red. Photokemi Nebula Filter and Star Reduction actions also brought out the nebulosity. A mild Orton glow added with Luminar Neo. Stacked, aligned and blended in Photoshop. Taken from hom
