We didn’t have a great deal of diversity in the shorebirds during this early season trip to the “central coast,” but, we had great numbers in the early migrating species like the Long-billed Dowitcher. There may have been some Short-billed Dowitchers mixed in here but none that we could confirm identity. The LBDO uses the central flyway predominantly while the SBDO primarily moves along the coasts during spring migration.
After M42 had began to drop to low in the western skies, making any further attempts at photographing it futile, I decided to try and find the newly discovered, long period comet, C2022 E3 (ZTF). I was unable to see it with my naked eye at my location, but with careful scanning using binoculars, I was able to find it. At 03:00, I was happy that getting it in the camera viewfinder wasn’t too difficult a task. I knew this wouldn’t be the best image of this comet, but I didn’t want to pass up the opportunity. This is a stack of 77 20-second images. You can make out the green color of the comet’s head, proposed to be due to the presence of diatomic carbon, along with two tails. The broader, warmly colored tail is the dust tail and the fainter tail below is the ion tail.
The comet’s closet distance to earth will appear on February 1st, where it will be close to the north celestial pole. The waxing moon will make it harder to see. So, if you plan on trying to see this one yourself, you should wait until the moon sets.
The Great Orion and Running Man Nebulas (M42 and M43)
After trying for three months, we finally had a night of very good conditions to create the closeup of these two objects that I have been hoping to accomplish. The winds were low enough that I felt comfortable using the big 300mm lens. We had zero clouds the whole night and although this was the night before the new moon, the 3% moon that was left didn’t rise until after 05:00. Humidity was high, so seeing and transparency weren’t the best and the frost was building, but I’ll take a night like this anytime. In addition, since these objects set around 03:00, I had the opportunity to photograph a new comet in our sky, C/2022 E3 (ZTF). This comet appears to have an orbit that won’t put it back by earth for about 50,000 years, so I thought now would be the best time to try for a photograph.
A part of the asterism known as Orion’s Sword within the Orion Constellation, the Great Orion Nebula (M42) is an enormous cloud (~40 light years in diameter) of fluorescent gas, composed primarily of hydrogen, which lies approximately 1350 light years from earth. It also contains traces of helium, carbon, nitrogen and oxygen. M42 is a diffuse, emission-type nebula that is home to star formation. The bright nascent stars, primarily Theta Orionis – the four stars that make up the asterism known as the “Trapezium,” are found within the bright core of the nebula. Via a process known as photoionization, these stars provide the ultraviolet radiation that excites the hydrogen and other elements to emit the visible light by which we can see the fine, multicolored mackerel patterns throughout M42. There are thought to be about 2800 young stars, mostly unseen via visible light imaging, within the nebula.
The M42 nebula is both the brightest and closest such star forming nebula to earth, making it one of the most viewed, photographed and studied deep sky object. Evidence suggests that the current brightness (equivalent to a 4th magnitude star) may be a recent phenomenon. This is supported by the fact that M42 and M43 were not mentioned by the early astronomers (e.g. Ptolemy – 2nd century CE, al Sufi – 10th century CE, and Galileo – 17th century CE) despite their close observations and records of this area of the sky. The accepted first discovery of M42 was by the French astronomer, Peiresc, who first published his observations in 1619.
The Running Man Nebula (M43) is so named for the vague specter that can be seen sprinting across this gaseous body. It is a wedge of nebulosity located northeast of the Trapezium and primarily illuminated by the 7th magnitude “Bond’s” star. I find that M43 is a perfect bit of color and contrast that tops off M42 very well.
Collecting the data (20/21 January)
Having had imaged this section of sky in December, I gained experience in collecting image data and processing using multiple exposure lengths. This is important for M42 particularly in collecting fine details in the outer dim gas and dust clouds while also capturing the details in the bright hot core. Overall, imaging went as I anticipated with the exception of a couple new issues that I explain below.
For this session, Miguel and I setup at Danville C.A., as usual, and Miguel brought along his partner, Leela. Miguel wound up collecting the data he needed earlier than I did, and he and Leela were on their way home before 01:00. The forecasts were mostly correct. There was a chance of clouds developing over us around 03:00 but when I was on the road home around 05:00, the skies were still clear. I want to thank my friend, Pete Kozich for his assistance in meteorological forecasting for this and past projects. That is always a big help and much appreciated.
One anecdote to share was something I expected to happen sooner or later. Miguel and I had just started our imaging when a pickup truck pulled into the parking lot, with the driver placing its beams down the road to where we were setup. I immediately thought this was going to be another meeting with a Conservation Agent. When it was obvious they weren’t going to pull out and head off, I stopped the camera and headed over to the parking area. When I arrived, I was met by a group of friendly hunters and their dogs who shared that they were hoping to do some coon hunting. They asked what we were doing and I told them, mentioning that their headlights and any additional lights would be detrimental to what we were trying to accomplish. Thankfully, this C.A. is pretty large with a few different access points. When they understood the situation, they graciously decided to allow us to continue without further disturbance and headed to a different location. I understand these areas are used by different folks with different purposes in mind and was thankful they didn’t try and push the point.
Over the course of this imaging session, skies were clear of clouds. Winds started at 6 mph and wound up around 2 mph by the end of the night. Temperature ranged from ~34 – 23 °F over the course of my imaging.
Astro-modified Canon 7D mkii camera, Canon 300mm f/2.8 lens, Skywatcher Star Adventurer tracker without guiding on a William Optics Vixen Wedge Mount. Gitzo CF tripod, Canon shutter release cable, laser pointer to help find Polaris and sky targets, lens warmer to prevent dew and frost on lens, dummy battery to power camera, cart battery to provide power to camera and dew heater, right-angle viewfinder to aid in polar alignment.
Lights taken (ISO 3200, f/3.2): 32 seconds (492 taken, 412 used in integration); 16 seconds (165 taken, 148 used in integration); 8 seconds (112 taken, 106 used in integration); 4 seconds (56 taken, 54 used in integration); 2 seconds (63 taken, 61 used in integration); 1 second (61 taken, 60 used in integration).
Darks: 30 taken at each of the six exposure times listed above.
Bias and Flats: Not taken. Removed most vignetting and some chromatic aberration while converting RAW images to TIF.
I admit, this one was a chore. Almost 15 hours in total, most of this in the stacking at the six different exposure lengths. I’m not completely satisfied with my compositing for the core of M42. Even though I’ve gotten a lot of experience with doing this in Photoshop, I still don’t have the skillset to combine the different stacks into something I picture in my mind.
I think I may be finished with Deep Sky Stacker (DSS). When attempting to stack the 32-second frames, DSS would only accept about half of them. Digging into the reasons for this, I found that DSS is particularly picky about only accepting subs that are above a threshold of star quality. Because I shoot with fast lenses, opened wide, and because I am using an entry level star tracker, my stars would not be considered top quality by any serious astrophotgrapher. I don’t particularly care about this. I’m focusing on the DSO, not taking pictures of fine, perfectly round stars. Wanting to use every possible frame that I deemed useable, and not able to find a workaround in DSS, I needed another option.
I decided to download a trial version of Astro Pixel Processor (APP) because I read that this software works very well, and it allows the user to set the threshold for the acceptability of the frames it uses. This seems to be a nice way to run stacks. APP can analyze every frame and then provide you scoring data for each frame on a few different parameters. It is then easy to set a threshold, letting the software pick the top 90%, for example, or selecting and removing the frames yourself based on your own judgements about what the rating data provide.
APP is definitely more complicated than stacking software I have previously used, but not nearly as complicated as something like PixInsight. Much of what APP offers I won’t have any use for, but, because it gives you the option for doing things either mostly automatically or picking and choosing the settings yourself, I think I have found my new choice for stacking.
A note about colors. I encourage the reader to look up images like mine to see the wide array of colors with which these objects are depicted. There are a few reasons for this. First, subjective decisions. Some imagers just like to play with colors and saturations to create what they like. Another reason is improper color balance choices. These are cases where the colors are not true to what you would see in visible light but were not necessarily the choice of the photographer. The equipment used is another reason for the color variation seen in different images of these nebulae. Some photographers use filter systems designed to pick up enhanced light coming from the specific elements, e.g., using filters that pick up more blue or green light emitted from oxygen or red light from hydrogen. When these frames are put together, there is always going to be differences between any two images and not necessarily like what the human eye perceives. It is my goal to create images that are as close to neutrally balanced as possible. But much like the question of what the proper pronunciation of Latin should be, there simply is no agreed upon answer for what are the trues color of many of these objects.
Problems and Learnings
It seems I can’t get through a session without a lesson or two to learn. I had three from this night’s imaging, but I am pleased that none of these wound up ruining my efforts for this evening and that I was able to diagnose the issues to avoid making these mistakes again.
During this session, the 300mm f/2.8, which until this night, had never had much of an issue with losing focus over the course of a night, began exhibiting this problem quickly. For the first couple of hours, I found I needed to check and reacquire focus nearly every 30 minutes. Then, it seemed to level off and hold focus for the rest of the night. The outside temperature was not changing rapidly, and I had the rig exposed to the elements for close to two hours before beginning imaging, hence my perplexity. I think I figured it out. I had setup everything and had it ready to go about an hour before sunset but did not turn on the dew heater until shortly before beginning imaging. The lens, having already acclimated and reaching the same general temperature as the air, began changing temperature when the lens heater was powered up, and therefore, began losing focus due to this change in temperature. I now realize that in the future I need to turn on the lens heater immediately after setting up, so the lens reaches its steady state before imaging starts.
My next lesson learned was even more perplexing. Early on, when beginning to take the 16 and later the 32-second exposures, I noticed a faint glow on one of the long sides of the frames. I knew that there was nothing in that portion of sky that should show up so profoundly in that area of my composition and that it must be something of external origin. I checked and made sure there was no light pollution center in that direction of the sky. I then thought it must be some stray light entering the imaging path somewhere. Maybe the lens hood wasn’t installed correctly and allowing light to “leak” in? During the night, I couldn’t figure it out. But, because it was relatively minor and did not directly affect the main objects, I put it out of mind, figuring I could probably fix it in post processing using the gradient removal software. Then a more worrisome development came to my attention. When looking at my dark frames, which are taken in near completely dark conditions, I saw the exact same glow in them! What was going on here? Now I was concerned. Was there a problem with my newly converted camera? Did they not seal something correctly when they put it back together?
I had to wait until I got some sleep before getting into this research and giving this issue some serious thought. I decided to try taking some dark frames in as dark of conditions that I could possibly make. The glow was still there. I felt I could safely eliminate the possibility that this was due to a leak in the body that was letting light in. Another factor that added to this mystery is that I used “Bulb” mode in my camera to take the 16 and 32-second exposures. I then thought this might be the issue. I noticed that while using continuous shooting while taking my light frames, the camera behaved and sounded a bit different that when I normally shoot this way in “Manual” mode. This must be the cause! But that wasn’t it either. I then tried a series of 30-second dark frames in “Manual” mode and found the glow in most of these as well.
Stumped, I began a conversation with Miguel and fired up the Google machinery. I’ll save you the rest of the unimportant details and let you know that with the help of Miguel and some experienced folks in the proper online forums, I discovered the cause of the glow. It was caused by something called “amp glow.” This is the term for the glow that is produced by the heat of the circuitry inside the camera and, as it turns out, is a common occurrence when shooting with “live-view” enabled with moded dSLR bodies. Using live-view for astrophotography with dSLRs is almost a necessity as it makes it much easier to find your target and obtain critical focus on the distant stars. Why had I not noticed this earlier in my previous sessions in which I also used live view? I am not certain. Maybe it was the combination of using ISO 3200 over the course of a longer evening, allowing for the buildup of heat?
To ensure this was indeed the cause of the glow I was experiencing, I performed some tests, taking 60-second dark frames with and without live-view engaged. Just as I expected, those without live-view engaged had no glow and those with live-view turned on showed it in every frame. Thankfully, this wasn’t a major issue with this project. Using the dark frames at these exposures, which also had amp glow, was supposed to result in the removal of the glow during the stacking process. This was not the case, unfortunately. Even though I had what I believe were the correct settings for this glow to be removed, that didn’t wind up working. I assume the fault lies in me not doing something correctly, but I don’t know how to fix this. The glow following the stack was so substantial, that gradient removal couldn’t do the trick in this case. This forced me to crop the final image more than I had originally designed to remove the area most affected by the glow. To avoid this problem in the future, my new imaging process will now be to use live-view only for acquiring the target and acquiring/checking focus. I will then turn this off and let the mirror slap away when taking my light frames.
The third issue, and simply a mistake in my strategy, is that I was unable to properly resolve the Trapezium. I had thought 1-second exposures would be good enough to allow me to properly resolve the four bright stars located in the center of M42, but these wound up being a rectangular blown out blob. I suppose that 1-second is still too much at ISO 3200. I should have checked these shorter exposures more closely so that I could have adjusted for this. Oh well, a reason to shoot this one again someday.
I have wanted to make this image since I first began thinking about getting into astrophotography. These paired nebulae are most astrophotographers’ first object chosen to image and, most likely, the most photographed DSO of all time. This isn’t quite the image I had envisioned in my mind, but it comes reasonably close. I think the primary reason it doesn’t match my expectations is my limited skillset with making composits in Photoshop. I also need to rethink my strategy in shooting high dynamic range objects. Maybe it’s a good thing not to have nailed it on my first try. This gives me the impetus to try again in coming years.
Here are a few songbirds I’ve photographed over the past couple of winter seasons.
Sarah and I traditionally conduct a caterpillar hunt on the weekend of her birthday in mid-September and 2022 was no different. This year we headed to Meramec State Park. I had recently heard of a short trail that covered the lush river bottom and contained hundreds of pawpaw trees. My hope was to find caterpillars of zebra longwing butterflies – a cat that has been elusive despite my many attempts at finding a late instar to photograph. We wound up short of this goal again, but we did find quite a few interesting species. I know Sarah will want me to mention that she did indeed win the day by finding more cats than I did. 🙂
Found near the road at Quivira NWR, this American Bittern cooperated a bit until it slinked back into the grasses.
Late last summer I had the great pleasure of attending my first couple of field trips with the St. Louis chapter of the North American Butterfly Association. Both of these walks were led by my friend, Yvonne Homeyer, the St. Louis chapter President. Yvonne is not only skilled and knowledgeable with butterflies but is an expert birder as well. These walks were held at Marais Temps Clair Conservation Area in St. Charles County, MO. I was thrilled to be able to get a number of first photographs of some fantastic species and was happy to do so while on a walk in good weather among friends. Thanks to all the participants who patiently helped me locate these insects and get the photos!
It’s about time I begin posting more from our Kansas trip from last April. The Blue-winged Teal is one species that is easy to find at Quivera NWR and Cheyenne Bottoms Wildlife Area. Dave and I had some great light on this evening. We set up low and waited for the Teal and Shovelers to drift by.
Many thanks to Chris Brown and his family! They had the incredible fortune of having a Mississippi Kite nest in their front yard this summer. The nest wasn’t really viewable from their house but with great luck, the chick after having left the nest, picked a branch right outside Chris’s son’s window to sit and wait for the parents to bring in food. At this point Chris invited me over on a couple of occasions to watch and photograph. Thanks for the use of your room, Avery! Unfortunately, these couple of days I began coming down with Covid-19 symptoms, inadvertently exposing the Browns and cutting off my time there. Thankfully, none of them picked it up during my visits. Here are some of my favorites of the parents bringing in cicadas and dragonflies.
Witch’s Head Nebula (IC 2118, NGC 1909)
IC 2118 has been on my list of potential deep sky objects to photograph since I first hear about her. I didn’t think I would have the skills or techniques to do her justice so soon but my plans for shooting M42 with the 300 mm lens were dashed again because of high winds. I studied the area and figured out my desired composition using a 200mm lens and a 1.6 x crop body camera and this is pretty much the result I was hoping for.
Why is this target so difficult for photographing? IC 2118 is known as a reflection nebula, meaning that there aren’t a lot of highly illuminous stars or star formation occurring within this collection of dust and gas. This very dim (apparent magnitude of 13) reflection nebula is primarily illuminated by the 7th brightest star in our sky – Rigel, the left foot in the constellation of Orion. Rigel, located 2.6 degrees to the east of IC 2118, is actually a system of four stars in close proximity. Rigel A is the primary star and is measured to be approximately 120,000 times more luminous than our sun, with an apparent magnitude of 0.13. It is a young star, approximately 8 million years old and has already burned through the hydrogen in its core. It is now burning heavier elements and will one day go supernova – one of the closest stars to us that will do this. When this happens, it is estimated that it will be as visible to us on earth as a quarter moon!
Back to the oh-so-appropriately named Witch’s Head. Due to the blue color of Rigel and the properties of this light scattering off of the gas and dust, this nebula appears blue in color, similar to the reason why our sky is blue on earth. Astronomers are unsure if the nebula is the remnants of an ancient supernova itself or just a collection of dust and gas. Although being close to, or perhaps a part of, the Orion molecular cloud complex, IC 2118 officially lies in the constellation Eridanus. This nebula is approximately 800 light years from earth and of course is absolutely huge. IC 2118 is roughly 1 x 3 degrees in our night sky and roughly 50 light years long. It is not visible to the naked eye from earth, but to give a size comparison of the amount of sky this object would take if we could see it, it would roughly be equivalent in length to six full moons in our night sky.
Collecting the data (27/28 December)
It was nice having two opportunities in December to work on astrophotography. Like I mentioned above, I was hoping to do a closeup of Orion and Running Man nebulas but with 10-12 mph steady winds with gusts above 20 mph, I knew I better not shoot with the 300 mm lens. IC 2118 was definitely on my list and could be captured with the much smaller 200 mm lens. The weather forecast was tricky and one of four weather apps suggested that clouds would ruin my night starting around 01:00. Even if so, which it did, I could still get up to six hours on the target.
I was by myself for this session, Miguel having something else, like sleeping I guess, going on this evening. And I setup at the usual location – Danville Conservation Area. It was truly windy and the temps hovered around the freezing point, which was warmer than the last time we went out.
Being such a dim target presented a significant challenge. Primarily, with a 35% luminated moon, I struggled a bit with getting exposure where I wanted. I would have liked to use ISO 3200, but when I started, this put the histogram peak above the 50% line. So I decided to use ISO 1600 using 30 second exposures. When the moon set at 22:04, I knew the histogram peak would drop and it did to a little less than the 20% mark. This was concerning because I knew this would be too close to get the signal to noise ratio I needed, especially with such a dim target. I contemplated changing the ISO up to 3200 but then I wouldn’t be able to stack the two sets taken at different ISOs with my dark frames while being able to use the process to remove satellites and plane trails. Instead, I opened up the aperture from f/3.5 to f/3.2. This gave me a third stop more light for each sub. I wasn’t sure if this was going to work, especially not being able to see the target in an individual frame!
As I feared, clouds came in heavier than 3 out of 4 weather apps and a meteorologist predicted! So, I shut down around 01:45 and made it home by 03:30 – an early night!
Astro-modified Canon 7D mkii camera, Canon 200mm f/2.8 lens, Skywatcher Star Adventurer tracker without guiding on a William Optics Vixen Wedge Mount. Gitzo CF tripod, Canon shutter release cable, laser pointer to help find Polaris and sky targets, lens warmer to prevent dew and frost on lens, dummy battery to power camera, cart battery to provide power to camera and dew heater, right-angle viewfinder to aid in polar alignment.
Lights taken (30 seconds; ISO 1600; f/3.5 and f/3.2) 671 taken, manually removed bad subs due to tracking errors, winds and clouds for a total of 433 used in integration.
Bias and Flats: Not taken. Removed most vignetting and some chromatic aberration while converting RAW images to TIF.
Not knowing for sure if my individual sub-exposures were going to be accurate, I was eager to get to the processing. After removing obviously bad sub-exposures, I plugged the 433 photos into Deep Sky Stacker and told it to use the best 90% of those, giving me a total of 3.25 hours of integration time.
It’s amazing how I can get sucked into processing these DSO images. This one only took me about four hours from start to finish but it seemed like no time at all. I also used GraXpert to remove gradients and various steps in Photoshop CS6.
Problems and learnings
This is definitely an object you want to shoot without light pollution and with as much time as you can possibly get on her. With roughly half my night lit by the moon and not getting as much time as I had hoped for, I am very pleased with the outcome. I hope to try this one again someday. Being a winter target, it is possible to get 8-10 hours on this target in a single night. This would help bring out the surrounding dust and provide better definition of the target herself. I did wind up using some subs that had light clouds, providing the halo around Rigel that normally wouldn’t be there. I don’t think this hurt the image, however. I could also shoot her with the 300 mm lens but this would eliminate Rigel in the frame and I don’t think would be nearly as interesting.
This is the second image of five I hope to make around the Orion molecular cloud complex. I did not expect to shoot the witch this soon but I am pleased that I have learned enough to make a competent image of this dim and challenging subject. After doing this a few months in a row, I am much more confident in what I am doing and using my kit has almost become old hat. As long as the weather gods bless me, I am feeling much more confident in being able to capture and process the targets that are within my capabilities. I hope to upgrade my tracking mount within the next year or two but I will continue with what I have at the present.