Une étoile circumpolaire trail composite avec Northern Lights, le 13 octobre 2017, tourné à la maison dans le sud de l'Alberta. La Grande Ourse est en bas au centre ;
5400 x 3605 px | 45,7 x 30,5 cm | 18 x 12 inches | 300dpi
Date de la prise de vue:
13 octobre 2017
Informations supplémentaires:
A circumpolar star trail composite with Northern Lights, on October 13, 2017, shot from home in southern Alberta. The Big Dipper is at bottom centre; Polaris is at top centre at the axis of the rotation. The bottom edge of the curtains are rimmed with a pink fringe from nitrogen. This is a stack of 200 frames taken mostly when the aurora was a quiescent arc across the north before the substorm hit. An additional single exposure is layered in taken about 1 minute after the main star trail set to add the final end point stars after a gap in the trails. So the aurora is a blend of 201 images. The ground is a mean averaged stack of 5 exposures to smooth noise. Stacking was with the Advanced Stacker Plus actions using the Ultrastreaks mode to add the direction of motion from the tapering trails. All are part of a 1000-frame time-lapse. Each frame is 3 seconds at f/2 and ISO 6400 wth the Sigma 14mm lens and Nikon D750.
