Comet NEOWISE (C/2020 F3) in a tracked close-up on July 20, 2020, showing the straight blue ion tail and the curving whitish-yellow dust tail. Even the ion tail was visible in binoculars and traceable out for 12° or so, or two 10x binocular fields. Here in the processed image it extends up into and beyond the Bowl of the Big Dipper, a distance of 20°. The curving dust tail extends about 15°. A bit of cyan colour is visible around the head of the comet. The bright galaxies M81 and M82, very tiny here, are at upper right. The two pairs of stars either side of the comet head are Tania (left) and Talitha (right), in pairs with the two stars each labeled Borealis and Australis. They form the feet of Ursa Major, but are also part of the asterism known as the Three Leaps of the Gazelle along with another pair to the west off frame at left. This is a median stack of six 1.5-minute successive exposures with the Canon EOS Ra at ISO 800 and Sigma 50mm lens at f/2.8, on the iOptron SkyGuider Pro tracker but unguided. Stacked and aligned automatically in Photoshop with the Scripts>Statistics function. Applications of Curves brings out the fainter tails without blowing out the bright head. I applied extensive sets of gradient masks to help remove the sky gradients toward the bottom (horizon). However, inevtiably some sky gradient colours remain. An application of ON1 Dynamic Constrast and a high pass filter helped bring out the ion tail details and subtle banding structure in the dust tail. Other than that I did not apply any local adjustments to the ion tail to accentuate its brightness relative to the dust tail. But as always, the long exposure of a camera reveals more than the eye can see. I shot this from Crawling Lake in southern Alberta on a near perfect night, though some light cloud or possible airglow still discolours the sky.
Comet NEOWISE (C/2020 F3) with the Northern Lights and a STEVE arc aurora to the left, all over the Waterton River at Waterton Lakes National Park, Alberta, on July 13-14, 2020. This was from the Maskinonge picnic area. The Big Dipper is at upper left. A very faint green picket fence aurora is at right above the comet, a characteristic of STEVE arcs. This was an astounding night for sky phenomena! This is a blend of a stack of six exposures for the ground and water to smooth noise, blended with a single short exposure for the sky, all 15 seconds at f/2 and ISO 3200, with the 20mm Sigma Art lens and Canon EOS Ra camera (with the Nikon-mount Sigma lens adapted to the EOS Ra with a Metabones F to RF adapter). LENR employed on all shots to reduce thermal noise this warm summer night.
