M31 – The Andromeda Galaxy – Redux (October, 2022)

My second attempt at the Andromeda Galaxy (M31)

I originally photographed M31 in August of 2020 as my first serious attempt in photographing a deep space object (DSO). I did not make many other attempts in DSO photography until the past couple of months where Miguel and I have had hard times thinking about anything else. There are multiple sides to this type of photography and so many ways to improve and learn. This is definitely the most technically challenging photography I have ever done. I’ll say this new attempt at M31 is a significant improvement over my first, mainly due to increased integration time and learning better processing techniques.

The Andromeda Galaxy (M31)
You can learn a little about this section of sky by visiting my first post. In addition, here are a couple other factoids about this galaxy. One of the coolest things I’ve learned since getting into astronomy and DSO imaging is the size of a lot of these objects relative to other things that we all routinely see in the night sky. Sure, stars are small in our vision and there are a lot of very small objects that need very large focal lengths to see. But, many DSOs are actually very large. We don’t notice them due to their low magnitude of brightness. Many nebulas cover large parts of our sky, for example. For M31, it’s apparent size on the long axis is ~ 3.167 degrees. The size of the full moon is ~ 1/2 a degree, so M31 covers an area a little more than six full moons!

Andromeda was first formally described by Persian astronomer Abd al-Rahman al-Sufi in the year 964. Did you know that many of the first astronomers were living in the middle east? It’s true – many of the stars still carry their original Arabic names. Andromeda and other similar galaxies were originally thought to be groups of gas and stars within our Milky Way. The discovery and proof that Andromeda was its own “island universe,” like our own, did not occur until the 1920s. Over the last century, M31 has been extensively studied and is now thought to contain ~ one trillion stars.

Collecting the data
The new moon period, which allows for the best low-light conditions for astrophotography, in October is troublesome. Miguel and I checked and double checked the forecast and found the best potential night was on October 22/23. We are finally getting some rain in eastern Missouri and most of this period is forecast for significant clouds. The night we chose was mostly cloudless but was not perfect. Winds were 10-13 mph with regular gusts up to 20 mph. In addition, seeing and transparency were on the poor side due to the winds and high humidity. This was not optimal, but it was still the best apparent night to try, so we did. To aid with the winds, we setup on the downwind side of a couple of hay bales and they did a pretty good job of acting as wind breaks. We imaged at my favorite site – Danville Glades C.A. 

Here I am during one of my every 30 minute checks of focus and battery power. Doing AP with a DSLR and regular lenses is quite a chore! Photo by Miguel Acosta.

Equipment 
I had originally planned to shoot with my Canon R5 and the Canon ef 400 mm f/4 do ii lens. This framed M31 very nicely in Telescopius and I was eager to see how this lens performed in astrophotography purposes. However, with the winds forecasted, I decided to use a smaller lens that would be less likely to be affected. I wound up using the Canon 7D mk ii and the Canon 200 mm f/2.8 lens instead. This put M31 slightly smaller in the frame, but I thought it would still stand out well enough after a marginal crop. 

I used the Skywatcher Star Adventurer without guiding and used my new William Optics vixen style base to mount the tracker on. This mount in combination of using a green laser pointer allowed for very good and easily obtained polar alignment. I’m happy to say that I need not dread getting PA any longer and I can make this step just part of the routine. 

Imaging 
We had some clouds early on in the night. This wasn’t too much of a problem because they cleared out by about 9:30 pm and Andromeda was still in low latitude sky glow until about 10:00 pm. Imaging went pretty well. I did not have to throw out many lights due to wind or tracking errors. One problem that did become apparent was the quality of the stars. When wide open, this lens produces fat stars with pretty bad chromatic aberration. This was probably exasperated by the poor seeing and transparency. I knew this could potentially be an issue but wasn’t too concerned as I was mostly concerned about the galaxy. Anyway, next time I will stop this lens down by 2/3rds of a stop to try and improve this. The settings I used were f/2.8, 30 second exposures at ISO 1600. 

Lights: 492 light images taken (manually removed obvious bad subs and used 447 subs for a total of 223.5 minutes of integration). 
Darks: 36 
Bias: 50 
Flats: Since flats are a pain to take and since I am using a camera lens that can be corrected for vignetting when processing the raw light files to tif format, I did not take or use flats for calibration. This was the first time I tried this and it seemed to work very well. This will be my new strategy going forward. 

Processing 
Deep Sky Stacker worked! This was the first time I had good enough quality subs that DSS would register and process everything. After about one and a half hours of processing, DSO had processed my linear image. Processing was the biggest learning revelation I had from this project. Pieces finally came together. After stacking in DSS, I used various manual techniques in Photoshop along with StarNet for star removal, GraXpert for gradient removal and Astronomy Tools action set. I finally have a big picture of my step-wise work flow and this should get easier and better going forward. 

Conclusions 
Including driving time, setup time, imaging time and processing time, I estimate it took about 20 hours of concentrated work to produce this one image seen here. When compared to my previous attempt of this object, I am quite satisfied by the results and the time spent was well worth it to me. The increase in integration time along with my improvements in post processing really paid dividends. Maybe I’ll try this target again in a couple of years if I have made improvements in equipment, techniques and processing. 

Clear skies! 

-OZB 

Forked Blue Curls (Trichostema dichotomum) and an Explanation of Focus Stacking

I know I posted some similar pics last year, but I can’t get enough of these flowers. Although we literally had thousands of these flowers blooming in the yard this year from seed I collected last fall, I didn’t get around to photographing them until on a WGNSS Nature Photo Group trip to Don Robinson State Park in early September.

Forked Blue Curls (Trichostema dichotomum)

These flowers are both tiny and deep in multidimensions. Because of this, a narrow aperture is typically required to photograph with enough depth of field to get all parts of the flower in reasonably sharp focus. However, stopping down the aperture needed for this greater DOF comes with a couple of problems. First, adjusting the aperture too much above f/14 or so begins to dramatically lower sharpness due to the diffraction of the incoming light. Second, and probably more importantly, a small aperture will also bring more of your background into focus. Depending on the closeness and business of the background, this can simply ruin a nice composition.

So, what’s another alternative to stopping down? This flower is a perfect example of when it is a good idea to use focus stacking. In focus stacking, the photographer takes several images at a lower aperture to get “slices” of the subject in focus. Depending on the size of the subject, the focal length of the lens you are using and the magnification you are shooting it at will determine how many of these slices are required to get the entire subject covered. Then, you combine the individual images, or slices, in the computer to hopefully get a perfectly sharp subject with the creamy out-of-focus background that makes a nice image.

Forked Blue Curls (Trichostema dichotomum)

For my macro focus stacking, I typically use a 180mm macro lens and shoot at f/8. Depending on the criteria mentioned above, I will typically need 10-50 images to cover a subject. There are a few ways you can go about taking the images needed for a focus stack. You can shoot them manually, typically taken on a tripod and moving the focus ring a little at a time, or by using a macro focusing rail, which you move your rig closer to the subject for each image. If you are using an autofocusing lens, there are also automated ways to collect the images needed for a focus stack. The one I use is a specialized extension tube that has a computer chip inside. I let the extension tube know what the focal length is of the lens and the aperture I have the camera set to, make sure my focus is just before the first part of the subject I want to focus on and then hit the shutter release. The camera will then take image after image, changing to a deeper focus with each one until either I feel I have covered the entire subject or the lens hits infinity. Finally, newer cameras allow you to focus stack using controls built into the camera’s software. These typically provide a wide range of options for the photographer to control. I imagine using this has somewhat of a learning curve. I have not used this in my Canon R5, partly because I like the simplicity of what I use and partly because you cannot use flash when using this feature in Canon cameras to date.

If you’re having troubles getting the types of images you want of small subjects under high magnification, give focus stacking a try. But, remember, your subjects need to be stationary!

-OZB

From the Garden – Filipendula rubra (Queen of the Prairie)

This was sort of an impulse purchase. I couldn’t believe I found this at a local nursery, and loving this species, I had to try it at home. I installed this in the front wildflower bed of our yard. I know that I’ll definitely have to keep this one sprayed for its protection as it is literal deer candy. The deer ate half of this inflorescence shortly after I took this photo.

Filipendula rubra (queen of the prairie)

Post Oak (Quercus stellata) at Victoria Glades C.A.

I can’t help but to marvel at this grand post oak every time I visit Victoria Glades in Jefferson County, MO. I’m always hoping to be there in good light and skies to take a worthy photograph of it. On a morning of a WGNSS Nature Photo Group field trip, I arrived a little early with this in mind. Not an interesting sky, but I used the bright sun to my advantage to create a starburst.

Regal Fritillary (Speyeria idalia) at the Cole Camp Prairie Complex

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

Back in late June, Miguel and I took a trip to the “Cole Camp Prairies” near Sedalia MO. Here, we were after a target I had long wanted to photograph, the regal fritillary butterfly (Speyeria idalia). Once abundant across the ancient prairies, lands that are now mostly used to grow the crops feeding us, the regal fritillary are now listed as a G3/S3 species, meaning they are vulnerable to extinction. The reason for this is that the regal fritillary host plants are violet species that only grow in the scarce remnants of the once vast ocean of prairies that covered much of the central United States. Fewer acres of prairie means fewer prairie violets that leads to fewer butterflies. Fortunately, the pitiful amount of prairie remnants left in the Show-Me State do still support this fantastic butterfly and Miguel and I did our best to find and photograph some.

The Cole Camp Prairie complex is a list of approximately eight mostly postage-stamp sized publicly accessible prairies located north of the small town of Cole Camp in Benton County. I did some research to find out which prairies had confirmed sightings in the previous years and which were more likely to have a sizeable population. I knew we would focus on these, but because these prairies are pretty close to one another, we wound up visiting seven locations just to see the differences between them and to give the entire area a good scouting for the regals.

Photographing a butterfly on the wing is no easy task! A regal fritillary (Speyeria idalia) male searches for one of the first females to emerge at Paint Brush Prairie.

Our first stop was at Paint Brush Prairie Conservation Area. This is one of the larger of the Cole Camp Prairies and was reported to hold one of the better-sized populations of regals. Our visit coincided with the early portion of the regals flight period and this would hold ramifications that would complicate the achievement of our goals. Here, we did find an estimated two dozen regals. However, these were all most likely males that typically emerge earlier than females. Although some plants were in bloom, these males were not interested in feeding. Instead, they were constantly cruising, inches above the vegetation, assumedly waiting for one of the first females to emerge and an opportunity to mate. We tried our best. Once in a while, one would stop to rest for a brief second or two, but it was never long enough to get in position, find focus and take the shot. I then tried to see if it was possible to photograph them in flight. This proved to be about as fruitless as it sounds. After hundreds of shots, I wound up with only a single keeper, pictured here.

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

Our next stop, just a quick drive west, was at Friendly Prairie C.A. This wound up being our most successful stop. Success in photographing these beasts lies in your visit’s timing with flowering plants. In late June, we missed the prolific blooming of most of the Echinacea and Asclepias and were a tad too early for the blooming period of the native Cirsium that support the energy needs of these butterflies over mid to late summer. Thankfully, we did find a few Asclepias tuberosa at peak bloom and the regals had found them as well. We only found four regals here, but they were cooperative indeed!

Miguel, ready for action at Friendly Prairie C.A.
A Halloween pennant photographed at Hi Lonesome Prairie. Notice the parasitic water mites that dragonflies often carry on the bottom of its thorax.

We continued our tour of the Cole Camp Prairies, visiting the holdings that the Missouri Department of Conservation had to offer as well as one restoration property owned by The Nature Conservancy. Towards the end of our time, we stopped at the largest prairie parcel in the area – Hi Lonesome Prairie C.A. This prairie was very dry and, perhaps consequentially, we found very few plants in bloom. There were, however, still a number of butterflies. Here we found monarchs and a diversity of swallowtail species as well as five regals. Almost all of these were flitting around the bushes that spotted the prairie’s many hillsides. This prairie also held some nice bird diversity. In addition to the ubiquitous Dickcissel, we found Grasshopper Sparrows, Henslow Sparrows, and Bell’s Vireos. Around a couple of this area’s large ponds, dragonflies were in abundance as well. I took some time to hop the electric fence around the larger pond, finding out the hard way that it was indeed working to keep out the cattle that graze the prairie, and spent some time working with gorgeous Halloween pennant’s (Celithmis eponina). See attached photo.

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

I had wanted to give the Cole Camp Prairies a good tour for quite a while. I’m happy that we spent the day doing this although I know it was but a snapshot over the course of the seasons. Finding the number of regals we did was thrilling and I’m happy to have gotten a few worthwhile photos from the day. Although these prairies are a good hoof from the StL, at a little less than a three-hour drive, they are still much easier than getting to other prairies in different parts of the state. Hopefully my next visit comes soon.

-OZB

NGC 281 – Pacman Nebula

The Pacman Nebula (NGC 281)
The Pacman Nebula is a large emission nebula that is approximately 48 light years across and nearly 9500 light years from earth. It was named for its resemblance to the popular Pac-Man character in video games, although you’ll probably have to use your imagination to see this in my image (Pac-Man is facing towards the top of the image). Unlike the the popular Namco mascot, this Pac-Man does not gobble up dots, it is actually creating them; NGC 281 is a star forming region that lies near the constellation Cassiopeia.

Collecting the data
Miguel, who is now getting serious into deep sky object (DSO) photography, and I met at what is now my favorite location for this work – Danville Conservation Area in Montgomery County, MO. This is classified as a Bortle 4 sky location and we were working under near perfect conditions of a new moon, no clouds, low winds and cool temps (mid to low 40s). Selecting a great night was one of the successes of this project. Miguel was just beginning to work on his new rig, attempting polar alignment for the first time and trying out his more sophisticated system of go-to and guiding. I use a simple unguided star tracker and the camera gear I use for normal daytime photography and had my target in mind and planned a night of imaging.

The photographer’s kit used in this project.

Gear used
Canon 7d mkii, 300mm f/2.8 lens is mki, Sky-Watcher Star Adventurer tracking mount with extra counterweight balance, Bahtinov focus mask, red-light scope, heat packs used for prevention of dew formation on lens, all setup on a sturdy Gitzo carbon fiber tripod and anchored to a concrete block.

Imaging details
Lights: Approximately six hours with 30 second subs (manually removed obvious bad subs and used 512 subs for integration.
Darks: 32 darks captured in field after imaging
Flats: 40 flats taken the next day from home
Bias: 67 bias images

Processing
Image shown here was stacked using Sequator. Stacked file was processed in PhotoShop CS6, manually following processes described in various YouTube videos. See below for details learned from this processing session.

Problems and learnings
This was a good night but definitely not perfect. Again, I struggled with getting proper polar alignment. My main issue was not identifying Polaris, necessarily, as we were easily able to find it with our naked eyes. The problem came from being able to correctly identify the star while looking through the reticle. Ultimately, I picked the most likely candidate and went with that. I didn’t have much star trailing in my 30 second subs, so I think I did an OK job. I did notice that the tracking was off and I had to recenter the target about once an hour, but that is due to using an unguided tracker and the weight of my rig. This is something I’ll just have to remember to do with future objects.

William Optics vixen style base mount. A must have!

I have picked up a couple pieces of gear that will dramatically help with achieving proper PA on future projects. First, I purchased a green laser pointer that I can shoot directly through the reticle and line up perfectly with Polaris. More importantly, I finally picked up a new wedge/base mount to support the tracker. This is the piece that is critical in getting proper PA. The mount that comes with the Sky-Watch Star Adventurer is severely lacking in many ways and is frankly a POS. The William Optics model I now have (see photo) is all metal, allows for more precise control in declination and is much easier to control right accession with. The differences are like night and day! I didn’t have these two things for imaging NGC 281, but I have them now and tried them in the yard one night and achieved perfect polar alignment in less than 15 minutes! I feel much less anxiety about this step now and wish I hadn’t waited so long to pick up this base mount.

The biggest mistake of the night was something I was aware of but simply forgot to handle. I left the settings for auto orientation on in the camera. This means, as the mount tracked the object over the course of the night, about half of my images were in the horizontal orientation and half of them were in the vertical orientation. This is a much bigger problem than it seems. In most software, you can change the orientation of an image with a simple mouse click. However, the orientation is actually embedded in the exif data of your RAW files. I came to find out that most stacking programs will not orient all of the files for you and, therefore, I was losing half of my light subs in the stacking process. It is possible to change the exif data to make them all the same, but this requires computer skills that I simply do not have. Thankfully, Sequator did accept all of my subs, but it is not the best software for stacking DSOs. I would love to fix this in the data I have collected for NGC 281 and be able to stack in Deep Sky Stacker or ASTAP one day, but I will definitely remember to turn this function off in camera in the future.

Processing after stacking was the usual barrel of fun. I found it a little easier than I did for M31, but I think I have a long way to go. I was hoping to get much more detail in NGC 281. I think I had ample integration time and feel there may be some detail I can pull out with better processing. Maybe the fault lies in my images themselves and I could do better with PA and tracking. It might also have to do with the focal length. With the 480mm focal length equivalent used for this object, I don’t have much more opportunity to improve here, but I could have used a 1.4x teleconverter and get 672mm focal length equivalent. I think there was room to do this with this object, but I would have had to recenter more often and lost some light gathering in the process. Maybe next year!

The author setting up for a night of imaging. Photo by Miguel Acosta.

Conclusions
Despite the final outcome, which I am satisfied with, this was a lot of fun. I’m finding that I can have fun doing almost anything as long as I am outside. This is getting truer all the time. Although this process has its frustrations and anxieties, I guess you can call that a “good stress.” I’ll always remember the pair of Barred Owls squawking away at each other and the coyotes howling and barking on at least three sides from where Miguel and I worked. In addition, while I was breaking down at about 3:00 am, two armadillos noisily burst through the grasslands, coming up to within ten feet of me to see what I was doing.

My hope is to continue this and image one object a month. I think I can sacrifice one good night’s sleep a month for such experience, learning and memories.

Clear skies!
-OZB

Catalpa Sphinx (Ceratomia catalpae)

Miguel and I found an aggregation of the catalpa sphinx moth caterpillars on a caterpillar hunt in early September. I have been looking for this species for a while so this was a nice find. Of the ten or so we found, one was infested with the parasitoid braconid wasp cocoons. See photos below.

Lesser Scaup Hen – May 2022

Photos taken of a Lesser Scaup hen taken from my canoe in Ellis Bay at Riverlands Migratory Bird Sanctuary in May, 2022. Due to the large area of white on the face and the lack of white wing bars in the primary flight feathers, I feel reasonably confident in calling this bird a Lesser Scaup, but please let me know if you have evidence to suggest otherwise.

Female Lesser Scaup
The white wing bars stopping at the primaries suggests this is a Lesser Scaup hen.