The past few days have offered several opportunities for photographing objects in the sky.
Mercury (Magnitude –0.2) and Venus (Magnitude –3.9) are very low in the evening twilight right now and a bit difficult to see with the unaided eye—but a camera can do a better job at picking out the small but bright planets. The two planets are separated by about 7°.
At the same time, Jupiter (Magnitude –2.0) and the Moon made a close pass last night with about 2.5° of separation. These, of course, were much easier to see.
And, a few days ago, the International Space Station (ISS) flew in front of the Sun as seen from my house. I didn’t even have to travel—just set up the camera in the driveway. The entire flyby takes less than one second. Warning! A proper solar filter is required. I use a filter made by Kendrick Astro Instruments.
Most of my Milky Way photographs are shot using a wide-angle (24 or 28 mm focal length), or ultra-wide-angle lens (16 mm focal length). These create an image that shows a large portion of the Milky Way. But sometimes it’s fun to zoom in a bit and focus (no pun intended) on a much smaller section of the sky.
A few days after the full Moon provided a great opportunity to do this. The Moon would not rise until about an hour after astronomical twilight ended and, more importantly, there were very clear skies.
I used a Nikon D750 body with a Nikon 85mm f/1.8 lens for this session. This is designed to be a portrait lens but I find it makes a pretty good astrophotography lens as well because of the excellent light-gathering f/1.8 aperture and the corner-to-corner sharpness resulting in nice round stars. At least, that is, when I get sharp focus and accurate tracking.
I shot 10 images of 120 seconds exposure time and used Long Exposure Noise Reduction (LENR). I was unable to use the 10th exposure because the sky was already getting brighter even though the Moon was still below the horizon. The result was 9×120 seconds or 18 minutes of light gathering.
I have several different applications (both Mac and Windows) for star stacking and alignment and chose to use Starry Sky Stacker this time with good results. Once I had the stack completed I used rnc-color-stretch for histogram stretching with final postprocessing done in Lightroom 6/Photoshop CS6.
This is the final result. I think the colors might be a bit too saturated—but I don’t dislike the result. Artistic license invoked here.
A few nights ago I had an opportunity to photograph the Milky Way under exceptionally clear skies. I wanted to do two things: One was to replicate an image I shot a few years ago and the other was to get a Milky Way/landscape composite with a moonlit foreground.
I headed out to Wupatki National Monument (an International Dark Sky Park) and set up in a dark parking lot with a moonlit landscape. The Moon was still well above the horizon and I took several long exposure images to get a good foreground. After the Moon had set, I shot the Milky Way (using a star tracker to eliminate star trails). Back at home, I would then merge the two images. The result is the image below showing the Milky Way aligned above the distant San Franciso Peaks with mesas rising on either side of the shallow valley. What also shows up is the large amount of light pollution in Flagstaff. Flagstaff is the worlds First International Dark Sky City but it takes a lot of work to keep the skies dark. I fear we may be losing the battle.
After completing this set of images, I moved to my next location to take my final shot. This is a single, 30-second image at high ISO (ISO 3200) with the tripod carefully centered on the stripe down the middle of the road. Comparing this shot with the one taken a few years ago indicates that the older image was blessed (if that’s the right word) with airglow in the lower part of the image giving it a much more interesting character. The newer image lacks this airglow but does have a more interesting horizon.
And now the North American Monsoon has begun to ramp up across the southwest and clear skies will be a rarity for the next few months. Time to start photographing storms and lightning!
It’s that time of year when the Milky Way is visible through much of the night. It is best observed when there is no Moon in the sky—and from very dark skies away from areas of light pollution. I wanted to capture both the Milky Way in a very dark sky and to capture Moonlight gently lighting up the still partially snow-covered mountains. So I headed out to Kendrick Park for some midnight sky photography.
The result is this composite of two images. The first was taken of the San Francisco Peaks as the moon was low in the west at around 1118 MST. This was a bit more than an hour before moonset (0030 MST). An exposure of 300 seconds at ISO 800 and an aperture of f/8 was used.
The second image was taken at 0047 MST shortly after the moon had set allowing the fainter stars in the night sky to appear. This image was also 300 seconds at ISO 800 and an aperture of f/5.6. To prevent streaking of the stars an iOptron Sky Tracker was used. The two images were then blended together.
Last week the two-day old crescent Moon (only 3.7% directly illuminated) provided a photo opportunity as it set over Upper Lake Mary. During the months of May, June, and July, the thin crescent Moon lines up with the long axis of Upper Lake Mary. This results in nice reflections of the Moon on the waters of the lake—but only if there is little or no wind. A bonus this month was the small planet Mercury was also setting in the northwest.
The image also shows the unlit part of the crescent Moon illuminated with Earthshine, also known as Da Vinci Glow. Yes, that Leonardo Da Vinci. Mercury can be seen just above the treetops on the far right side of the image.
With exceptionally clear skies it was a good time to capture images of the zodiacal light. Here is what Wikipedia has to say about this astronomical phenomenon.
Zodiacal light is a faint, roughly triangular, diffuse white glow seen in the night sky that appears to extend up from the vicinity of the Sun along the ecliptic or zodiac. It is best seen just after sunset and before sunrise in spring and autumn when the zodiac is at a steep angle to the horizon. Caused by sunlight scattered by space dust in the zodiacal cloud, it is so faint that either moonlight or light pollution renders it invisible.
Both images above clearly show the cone of light extending upward. In the upper portion of both images is the Pleiades star cluster with the planet Mars just below and to the left.
It’s unfortunate that Arizona’s dark skies aren’t as dark as they could be. Increasing population and expanding cities throws more light into the night sky. And our state legislators seem to think that bright billboards are more important than the dark skies needed by the many telescopes located in the state.