The International Space Station in a dawn pass, as it flies away to the east after passing overhead. This was the morning of July 15, 2017. Blended in are images taken 20 minutes later of a pair of Iridium satellite flares in the dawn, the one below (Iridium 54) being the first to appear, at a predicted magnitude of -7, while the one above (Iridium 90) appeared one minute later at magnitude -3. Venus is the bright object at lower left in the dawn twilight above Aldbaran and below the Pleaides. Capella is at far left. The waning Moon is overexposed at far right. This is a bit of cheat as the Iridiums were taken later than the ISS shots, but with the camera not moved and shooting a time-lapse through the entire sequence, from ISS appearance until the expected Iridium appearances later. The sky for the Iridiums was brighter and bluer than for the ISS set, so that had to be corrected for in brightness and selective colour adjustments. This is a useful image for comparing the ISS and Iridiums to Venus for brightness. However, by the time the ISS got into the east here, it had dimmed quite a bit from its peak in brightness overhead. The set for the Iridiums is a composite of 8 exposures, all 10 second exposures at f/2.5 with the Rokinon 14mm SP and Canon 6D. The set for the ISS trail is a composite stack of 24 exposures for the ISS, masked onto a single background image of the sky taken just before the ISS entered the frame. This kept the stars as points rather than trails, while the ISS trailed across the sky. The gaps are from the 2 second interval between 10-second exposures. All with the Canon 6D and 14mm Rokinon lens at f/2.5.
A multiple exposure composite showing the arc of the Full Moon of July 9/10, 2017 low across the southern sky on a summer night from dusk to dawn. This illustrates the low arc of the Moon across the sky in northern summer, from southeast at left to southwest at right. The sky is a blend of three long exposures: • for the dusk 10 p.m. sky (left) with crepuscular rays in the clear twilight, • the 2 a.m. middle-of-the-night sky with the Moon nearly due south (middle) with stars and iridescent colours around the Moon in light cloud, • and the dawn 5 a.m. sky (right) with increasing clouds hiding the Moon. The Moon disks come from a series of short 1/15-second exposures, to record just the disks of the bright Moon. I took shots every minute but selected images taken at 10-minute intervals here for the composite. Taken from home on a warm and dry summer night with no dew! Stacked and blended in Photoshop, with Lighten blend modes and gradient masks. Shot with a 15mm full-frame fish-eye lens and Canon 6D.
