When the moon, in its monthly travel around Earth, moves across a bright star, it is called an occultation. On this date, the moon is moving toward the bright star Regulus. Here is a superposed series of pictures taken over 1 hour as Regulus apparently “approaches” and then is eclipsed by the moon.
In 2007 a comet passed through our neighborhood and allowed me a chance to try the high dynamic range (HDR) imaging techniques that were being developed at that time. The idea is to combine a range of exposures to get a large range of detail. In this case 10 exposures covering the range from 1 second to 8 minutes are combined, selecting the best tonal information from each. This allows the otherwise obscured ion cloud surrounding the dusty nucleus to become visible as a faint blue-green glow. I was able to use this image as an HDR example in a conference presentation I made on this topic the following week.
The constellation Orion is a distinctive pattern in the winter sky. Look for the three-star belt, with another three-star sword hanging from it. Here he is with some of his less visible friends. The large red arc is Barnard’s Loop, which encircles the Orion Nebula (lower of the two red areas) and the Horsehead and Flame Nebulas.
Betelgeuse is the red giant star at Orions shoulder, not to be confused with the circular red Rosette Nebula to the left. The bright blue star at the lower left is Sirius (the Dog Star), the brightest star in the sky, and sailing above it in the blue river of the winter Milky Way is the red wisp of the Seagull Nebula.
After the hiatus while I compiled my Nightscape Odyssey notes and photos, I now return to my longer term project: “Coffee Table Nightscapes”, a collection of photos acquired over the years, often on business trips or summertime travels. I don’t pretend to be a competitor to APOD, where you will find spectacular astronomical imagery each and every day; rather, this is a low key way to share a few pictures that I enjoyed taking, with people that may appreciate them.
I resume the series with this image that someone else took. The Veil Nebula is a striking object in the sky and a popular target for astrophotographers. The view in the eyepiece of the telescope shows a faint fuzzy gray wisp of cloud, but cameras record something else. I was curious about what its actual visual appearance would be, if we could actually see it in full color.
The Veil Nebula is a supernova remnant– a star exploded, casting off a shell of gas that expands outward. The gas is hot and ionized and emits light at characteristic wavelengths. Hydrogen glows red at a characteristic 656nm, and also a blue-green at 486nm. Ionized oxygen emits green-blue light at 501nm. Most pictures of the Veil show a bright red cloud because the red H-alpha light is easy to record on film and CCD sensors. It is a challenge to display the blue-green colors because it falls in the gap between the blue and green-sensitive layers of film, and other imaging systems.
Figuring out how to make an image that was “colorimetrically correct” took me down a particular path of color science that resulted in a paper presented at the annual Color Imaging Conference. This image was my primary example among others, that were featured in the poster presentation (scroll to the end to see them). If you are still not convinced, try getting through the full technical details published in the Journal of Imaging Science.
The pictures I will be subsequently sharing are not this technically demanding. Whether simple or complex, simply enjoy them for their visual and inspirational value.
If you are interested in my occasional contributions to Thor’s Life-Notes, I invite you to follow along.
A mostly clear night, and a new lens to try out! A lens I was hoping to use to capture wide-angle views of the Milky Way, and of northern lights, should I ever be in a position to do so.
I headed to Baylor Park, which is the home of Eagle Lake Observatory, operated by my astronomy club. I wasn’t there to use its facilities (though others were). I just wanted a clear view of the sky outside the city, somewhere I could practice techniques for making timelapse sequences, preferably alone, where I could make mistakes without an audience.
The internet has evolved tremendously since its early days when I first tried to use web pages to show the results of my nighttime photography. Back then, our (dial-up) Internet Service Provider (ATT) offered a home page and a URL subspace to their customers. I took advantage of it and crafted some pages to hold my pictures and stories. Later, I acquired my own domain, nightscapes.net, found a host, loaded my stuff onto it and even got some professional help to re-organize when it became unwieldy.
I learned that maintaining a website can be a lot of work; the technology evolves, links and scripts break, web page conventions, html standards and visitor expectations change. I’m not a programmer (despite a lifetime of doing it), and my interests are in the art and science of images, not the latest network and browser technologies for supporting the latest desktop/laptop/tablet/phone displays.
So I was excited to discover a website service oriented toward photographers, a platform with a small army of support people who maintain it, with features that display photographs at their best, regardless of display or browser, keeping up with the latest updates to internet programming standards. They offer additional services for professional photographers (“buy print”, etc), and at an earlier time I might have subscribed to them.
But I am happy now to keep the shopping cart icons suppressed and not distract from the images themselves.
I have transferred my collection of nightscapes accumulated over the last two decades, over to smugmug, where you can find it at thorolson.smugmug.com. I know people don’t power-browse through large collections of pictures, so I consider this to be really more of an archive, to continue my project of making a digital coffee table book of my favorites.
But I will also use the site to display my more recent work, as I complete it. It will be a relief to have a way to do so without the overhead of manually creating and integrating new web pages for them.
I intend to make posts to this, my personal website, when I add new photographs. I invite you to subscribe or “follow” me, which will send you an email when new posts are made. I am not very prolific in my art, so you will not be inundated, and if you are intrigued by the types of pictures I like to take, well, I take enjoyment in sharing them and would love to have you as a follower.
By the miracles of modern technology (a technology I contributed to!), it is possible to self-publish a book without a minimum printing run of thousands or more. I recently took advantage of one of these services to make a limited edition of my collection of stories and essays, Nightscape Odyssey, posted previously on this site.
It was tricky to get the layout just right; it took two proofs, but I’m happy with the result and the experience was satisfying, especially taking delivery of the final copies. Even more satisfying was giving them away as gifts.
If you didn’t get one, it was because you probably aren’t one of my nephews or nieces, whom I felt should have some artifact of their odd uncle’s interests, and stories about what road trips were like way back when. Don’t worry though, if you really want a copy of this book, the same company that published them for me can make one for you! You’ll have to pay the going rate however, and you may find it more than you want to shell out for just another coffee table book. (https://www.blurb.com/b/10435240-nightscape-odyssey)
But if you don’t insist on an actual physical hard-cover book, Nightscape Odyssey can be had for free! A pdf version is available for download (20MB). I hope you enjoy it!
This is a favorite target for astrophotographers. It’s a famous image, but quite challenging to capture, partly because it is only visible during the winter months when Orion the Hunter is up. The weather conditions will always be cold, at least in the northern latitudes, and so winter gear is required.
It is not easy to actually see this target. The nearby bright star, zeta Orionis, is a convenient marker, but its glare easily washes out the faint glow of the Horsehead and another nearby object just below zeta, the “Flame Nebula”.