M31 – The Andromeda Galaxy

My first attempt at the Andromeda Galaxy (M31)

During the most recent new moon, I finally took out my star tracker and kit to try my hand at photographing a deep sky object (DSO) for the first time. I knew this was going to be challenging and this first attempt would be more for learning than producing an image that I would be excited about. However, thankfully it was both – it was a beneficial experience in that I got practice in all the process surrounding making an image of this sort (I will go into details below), and at the same time the final image turned out better than I expected, especially considering the challenges I had. For those of you who don’t care about the process, you can stop reading here – I won’t blame you. For those of you interested, I will provide some of my notes and things learned. You can tell me if it was worth the hassle or not.

The Andromeda Galaxy (M31)

The Andromeda Galaxy is also known as Messier 31 and NGC 224. It is classified as a barred spiral galaxy and is about 2.5 million light-years from earth. It is the largest galaxy in our local galaxy group and is on a direct path to merge with our Milky Way in about 4.5 billion years.

Did you notice? In this image there is more than just the M31 galaxy. There are two other galaxies that move along with Andromeda. Messier 32 is on the bottom side of M31 at about four o’clock. M32 is a compact elliptical galaxy and is comprised of mostly older red and yellow stars that are densely packed. Messier 110 is above M31 in this image and is a dwarf elliptical galaxy. There apparently are at least 11 other satellite galaxies of M31, but none that are apparent in my image to my knowledge.

Collecting the data

For my first attempt, I traveled to the Astronomy Site at Broemmelsiek Park in Defiance, MO. This is an excellent place that provides several concrete platforms along with electrical access for those with equipment that needs it. I did not, but I was looking for an area not too far from our home to find as dark of skies as possible. The sky at this location (Bortle class 5) is darker than where we live (Bortle class 6) and is 25 minutes away. This is a pretty good site for viewing the night sky. I was really excited when I turned my birding scope at 60X power to Jupiter and was not only able to view the banding and colors of the planet, but could also make out four of its moons! However, there was still enough light pollution here to make serious astrophotography a bit of a challenge. Unfortunately, this was more of a challenge due to where M31 was located in the first half of the night. At this time of the year M31 rises from the NE sky and it was not until ~ 11:30 pm that the galaxy rose enough out of the skyglow of civilization to make me a little more comfortable.

For this attempt I was using a Canon 5d mk iv camera and a Canon 300 mm f/2.8 is mk i lens. I balanced this heavy kit on the Sky Watcher Star Adventurer Pro Pack star tracker. Because of the weight of this kit, I used an additional counterweight and bar to achieve balance. This is near the weight limit that this star tracker was designed to hold.

The first step in going about this is to get polar alignment with the celestial north pole. I won’t go into too much detail here, but I found this to be particularly problematic. After trying for 45 minutes I eventually decided I was “close enough” but definitely not at optimal alignment. Getting as close to perfect polar alignment is critical at longer focal lengths and exposure times in order to capture the stars as pinpoints of light. A big part of my problem here was working with the mounting “wedge” that comes with this tracker. I found it quite difficult to get the precise control that is necessary to align Polaris where it needs to be. I will eventually need to replace this wedge with one of higher quality.

After getting marginal polar alignment, my next step was to mount this rig, get it balanced and then point it at the target all while not moving the tripod at all! I am sure I moved it somewhat off the alignment that I managed to get. Because of the light pollution, I was unable to see M31 with my naked eye, which is possible under dark enough skies. This made locating M31 more challenging than I expected. With the help of star charts and astronomy apps on my phone, I eventually found it by taking shorter exposures with very high ISO to be able to compose close to how I wished. This probably took another 30 minutes.

With the mount polar aligned, the target in my sights and the tracker running, I was finally able to collect my data. My settings were as follows: 20 second exposure time, f4 and ISO 1600. A little explanation here is needed. With this tracker and kit, I could theoretically get between one and two minutes per exposure. However, with the imperfect polar alignment I knew I had and the fact this was my first attempt, I decided to go with a shorter exposure. For my aperture, I gave up a full stop of light. However, I was worried about how the stars looked fully open and decided at the last minute to close to f4 to gain a little in the IQ arena. I am not sure this was the best decision or not and will probably try wide-open next time..

I collected 265 “lights” before clouds, that were completely not predicted by all of my weather apps came in and closed me down for the night. Later I cut this down to 225 lights that were unaffected by clouds or airplane lights for a total exposure time of 1.25 hours. While in the field you are supposed to take “darks” – these are frames at the exact settings under the same environmental conditions but you throw your lens cap on. These images are then used by the computer programs to remove the digital noise that is produced during capture. Somehow I forgot to do this in the field and did not remember until I was slipping into bed at 3:00 am. So, I got out of bed and went outside to take them.

Processing the data

It may seem crazy looking at this image, but I spent around 12 hours processing this. Much of this time is due to me not being very familiar with what I was doing. I also prefer to process as manually as possible, and used no specialized plug-ins in Photoshop.

Prior to Photoshop, all of the data needs to be stacked in the computer by specialized software. I first tried to use Deep Sky Stacker (DSS) that I have used for this type of work before. However, I ran into problems. After loading all my lights and calibration frames the software refused to run and gave me typical ambiguous reasons. Doing some troubleshooting online it looks as though my data weren’t good enough – apparently my stars were not round or sharp enough and I could do nothing to get DSS to process my data. I then played around with a couple of other free astro-stacking softwares. Most of these were far too technical for me to easily learn them. I finally found Sequator and this worked great. It does not accept “bias” calibration frames, but I doubt that I could recognize their absence in the final product.

I then took the stacked image and went through the “stretching” process in Photoshop. This is where you increase the local contrasts, trying to bring out details in the arms of the galaxies, nebulosities, etc. There are a number of steps involved in this last bit of processing. Much of what I did I learned from Charles Braken’s book, The Deep-Sky Imaging Primer and YouTube videos from Nebula Photos, Peter Zelinka and others.

Conclusions and what I learned

I realize this type of image is built mostly by technology. There really is not much subjectivity when making images of deep-space objects. It either looks like the thing or it doesn’t. I also realize that there are people doing this that have much more appropriate equipment and knowledge and can produce a much better version of a DSO than I could no matter how much I practice. However, I have found it very rewarding to be able to produce an image of M31 myself, especially using camera equipment I already owned and use for other things.

Here are some things I believe I have learned and can potentially help me improve in my future attempts at making DSO images. If you are an experienced DSO imager and can offer any further suggestions, I would be very much appreciative!

  • Getting better polar alignment
    • Getting more practice should help here and I will try and do this on nights that I am not planning on shooting, potentially from my yard.
    • I have read and seen videos where people are suggesting upgrading the wedge mount and I will do this eventually.
  • Collecting more data
    • I believe I could pull more details from the galaxy’s disk, including colors by collecting more data. I was limited by clouds for this one, but next time I hope to get at least four hours. I know that some pool data collected from multiple nights, but that is another layer of complexity I probably do not need right now.
  • Finding darker skies
    • There is no doubt that skies with less light pollution will allow for better data collection at a faster rate. This will definitely help in pulling fine details and colors from DSO’s. There are light pollution filters, but I have heard mixed thoughts regarding their benefits.
  • Beware of dew
    • I knew this, but forgot to take the heating elements to wrap the lens barrel in order to prevent dew forming on the lens objective. Thankfully, the lens hood seemed to protect from this, but at the end of the night I did notice a thin haze of condensation on the lens.
  • Learn more on processing
    • There are numerous ways to skin this cat and I hope to learn more by watching more techniques on YouTube. With trial and error, I am certain that I can improve the final image by learning more here.

Other than the above, the only thing I can think of that would make a big difference is purchasing technology. People who really get into this use specialized telescopes, specially modified cameras, guided trackers run by computers, filters and much more. However, I do not intend to go down this road and believe I can produce images that will satisfy me with the equipment I already have.

If you have an interest in DSO photography and have the basic equipment, I urge you to give this a try. All you need is a camera and lens that is about 100 mm – 500 mm. A star tracker is definitely helpful but not required! You can shoot DSO’s with simply a tripod. Other than that you will need to learn just a few things on how to adjust the settings on your camera and where to point.

-OZB

 

 

 

C/2020 F3 (NEOWISE) Comet

C/2020 F3 (NEOWISE) Comet in the northwest sky after sunset at Duck Creek C.A.

The NEOWISE Comet, whose actual name is C/2020 F3, was a pleasant surprise for the astronomical community who await such events as a newly discovered comet. First discovered in late March, the comet grew steadily brighter, eventually becoming the brightest comet to be seen in the northern hemisphere since Comet Hale-Bopp in 1997. According to the experts, this comet had an orbital period of about 4,400 years prior to making its latest trip through the inner solar system. It will now be another 6,700 years before beings on earth will be able to see it again.

C/2020 F3 (NEOWISE) Comet image taken at 200 mm focal length

I have long had a very strong interest in astronomy and astrophotography and the current pandemic has allowed me to do quite a bit of studying on both topics. Hopefully soon I can get the practice in this area that I desperately need. Although it has some issues, I was relatively pleased at capturing the closeup of the comet pictured above.

Although I had a star-tracking mount that would have been perfect for this situation, I had not yet used it so I did not make this the first time. This image was “untracked” using a full-frame camera and a 200 mm lens. It is comprised of 20 “light” images (the actual photos of the comet) taken at 3.2 seconds per exposure. The aperture was f/2.8 and the ISO/gain was 6400. I combined these images with 10 “dark” frames for noise reduction purposes.

The processing here could be better and I might give it another try sometime. But, both tails of the comet are visible and I think the background stars came out alright as well.

Milky Way at Lee’s Bluff, MO

After awhile the comet began to dive towards the horizon with the remnant glow from twilight. I happened to show up at Lee’s Bluff on the same night as accomplished Missouri nightscape photographer, Dan Zarlenga, and so we both turned our tripods around to the south and found this lovely scene. Here, the Milky Way has recently risen above a nice foreground of trees. Again, I wish I would have been a bit more prepared with a plan, but I guess this isn’t too bad.

-OZB

 

Floating the Upper Current

Upper Current in Autumn
Upper Current in Autumn

I’m finally ready to share a few more images from a float down the upper third or so of the Current River that Steve and I had the great fortune to experience this past October.  We started at navigable mile 8.0 at Cedar Grove Access and pulled out three days later at mile 51, the confluence of the Current and that other, oh-so desirable, Ozark stream – the Jacks Fork.  If one floats slow and quiet, the opportunity to see wildlife is very high in this National Park (Ozark National Scenic Riverways N.P.).  I’v shared a couple of images of these guys previously.  I believe we found 8-9 Mink during the first day of this float.  It was enjoyable watching them busily hunt along the stream banks, mostly oblivious to our presence.  As usual, Steve did a great job in keeping us quiet and pointed in the optimal direction for capturing some images.

American Mink
American Mink

It was quite a challenge to keep up with these guys as they fished.  This one below had caught a nice-sized crayfish and barely slowed to stop and enjoy his snack.

Ozark Lobster!
Ozark Lobster!

Here is a photo of one investigating the water prior to dipping back in.

Testing the Water
Testing the Water

Not only does a float down the Current allow for great observations of wildlife, but many geological features are most easily seen by being on the river as well.  Cave Spring can now be accessed via a nice newer trail, but it is much nicer accessing it by boat.  The endpoint of a vast and interesting karst drainage system, Cave Spring rises from the back of a short cave.  At the rear of this cave one can guide a boat over the vertical conduit of the spring, which is ~155 feet deep!  What an eerie sensation it is to shine your light down and still see no more than a fraction of the length of the conduit shaft.  In the image below, I am on a dry exposed shelf adjacent to the spring’s outlet and Steve is guiding the canoe towards the river.

Cave Spring
Cave Spring

Pultite is a spring found on this upper stretch of the Current River that is surrounded on all sides except the river by private property.  This means that one must boat or wade/swim to visit it.  At only ~ 1/10 the output of Big Spring, Pultite is still quite a good-sized spring with and average daily output of ~ 25 million gallons.  The effluent channel on this one is quite attractive and I hope to visit more often.

Pultite Channel
Pultite Channel

If day one was for the Mink, day two was our River Otter day.  We had no Mink, but 5 or 6 of these large weasels were spotted.

North American River Otter
North American River Otter

Not to forget the birds!  These days, a trip to nearly any permanent Missouri water source will likely bring an encounter with a Bald Eagle.  Observing these guys in the Ozarks will never get old to me.

Bald Eagle
Bald Eagle

Another constant companion on these floats are the Fish Crows, here pictured finishing up a little Ozark lobster.

Fish Crow
Fish Crow

We were fortunate in having mostly clear and dry skies on this trip, which allowed us to throw our bags directly on whatever gravel bar that struck our fancy and sleep directly underneath the stars.  A morning fire was necessary – not only to burn the dew off of our sleeping bags, but of course, for the river-water French-press coffee.  Dark skies on these streams afford great opportunities for astrophotography.  My only wish for this trip is that I was a little more tolerant of the cold, tiredness and laziness that limited my patience for getting better nightscape images… 😉

Nightscape on the Upper Current
Nightscape on the Upper Current

I will be posting more images of this trip on my Flickr account in the near future.  Thanks for visiting and I hope to post again in the near future.

-OZB

 

Dunn Ranch Prairie, July – 2013 Post One: Astrophotography

I had been wishing to visit Dunn Ranch Prairie in Harrison County, Missouri for a few years.  Part of the Grand River Grasslands, Dunn Ranch, along with Prairie State Park to the south is one of the two largest contiguous prairie habitats in Missouri.  Fortunately, Dunn is home to about 1000 acres of original, unplowed prairie alongside parcels that are in various stages of prairie reclamation via reconstruction activities by The Nature Conservancy staff.  With help from contacts at TNC (Hi and thanks Amy, Hillary and Randy!) and a recently found twin brother, Steve, who is as willing, able and interested in getting elbows deep in whatever Nature and the outdoors puts in our path, I had that opportunity as part of a five day excursion to the western half of the State.  We made stops to visit other prairie and marsh remnants nearby, but Dunn Ranch and adjacent Pawnee Prairie were our base.  I hope to provide tidbits of information about these endangered habitats and discuss some of the trials that TNC faces in these reclamation efforts and provide hopefully interesting accounts of Steve’s and my excursion in future posts where I plan to discuss birds/wildlife and landscape photography.  This first post is dedicated to astrophotography.

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Astrophotography has been of interest to me for some time now.  Being born and raised in urban environments, I can count on one hand how many times I’ve been able to witness a dark, clear sky – relatively free from light pollution.  Making images of this type of sky was one of the major goals for this trip.  Even without the aid of telescopes and tracking mounts, astrophotography with the dSLR can be a fulfilling challenge.  I scoured the web for months prior to the trip, trying to find techniques and tips for success.  With so much to consider, I knew this was going to be a mostly trial and error experience.

The internet is full of great “how-to” articles on how to go about making nice astrophotographs, so I will not go into too much detail.  We were fortunate in a number of ways concerning the environmental conditions for this endeavor.  First, obviously, one needs clear skies.  The first couple of days (and nights) were a bit overcast, but on the night all these images were taken, we had a mostly clear sky.  Second, for taking photos of stars, it is optimal to have little or no moon.  On this particular night, the moon was just a couple days past “new”.  But, that did not matter because the moon was almost in perfect sync with the rising and setting of the sun.  On this night, the fingernail moon was below the horizon by 10:00.  So, we had two important factors in our favor.  Other issues to consider are light pollution from ground sources.  We thought we were on the winning side here, being so far removed from any city of significant size.  What we came to discover is how much the camera’s sensor will pick up artificial light sources.  Even well past midnight, all the images I made show glow from the horizon, illumination that was not noticeable by the human eye.

Startrails Dunn 1

One other potential headache for consideration is aircraft and satellites moving through your frame.  Depending on the specific technique you use to create a star-trail image like the one above, you will either have one long exposure of up to an hour or longer, or a series of shorter images taken in continuous fashion and combined later in the computer.  Either way, in most areas of our country you will pick up the light signatures of these aircraft in your images.  I was quite surprised by the numbers of these trails that were picked up on the camera’s sensor.  In making the two composite-made star-trail images in this post I spent several hours painstakingly removing these by hand from hundreds of individual images used to generate these composites.   The yellowish green lights are trails from lighting bugs that collected over these images.  I decided to leave these alone.

IMG_5561

Although it may be pretty, a photograph of the stars alone with normal focal lengths usually holds little lasting interest.  I knew that to make something interesting and to relate it to place, I needed to find something unique and attractive to position in the foreground.  This would make a complete image.

The couple of days or so before this evening, I was checking out the landscape around Dunn, looking for these potential foregrounds and asking Steve to help me remember their locations and the general directions in which they faced.  These cut-steel/iron signs were quite popular with the different ranches in the area and I assume someone makes them locally.  I fell in love with this one on a prairie hillside at Dunn and knew I had to try this.  Unfortunately, this was getting quite late into the morning and I did not have the energy left to give it my all.  I used a longer focal length because of the distance of the sign from the road.  This gives a somewhat pleasant side effect of allowing for star trails to record in less time than it takes for a wide angle composition.  This image is one exposure of about 11 minutes.  If I had known the potential here, I would have given it more thought and probably put together a longer composite series to lessen the horrible noise and IQ observed in the RAW image.  Oh well, maybe next time.  Oh yeah, in this photo, the light pollution from the horizon works pretty well in back-lighting the sign and making some nice silhouettes of the prairie forbs.  We tried a bit of light painting, but it came nowhere close to this.

P.S. Can you name the constellation caught in this image above?

Startrails Dunn 2B

The image above I believe is my favorite of my astrophotography attempts.  I wish I could say I did my homework and knew exactly where the north star was and positioned it oh so perfectly between the gate posts.  Steve and I could not say for certain (Do you know how many stars there are up there!?).  All I did was try my best to center the gates in the middle of the frame as best we could in this dark night.  I wish I could say I knew exactly how long (how many exposures) I wanted/needed to get the rotating perspective seen here.  All I did was decide that I would try and fill an entire eight gig memory card.  This equated to about 350 13-second exposures for a total “exposure time” of about 75 minutes.  I did not even know how I was going to stack these together in the computer.  I knew there were a few specialty software as well as a manual option in PS.  I tried three different freeware apps and discovered the last one I tried, “Startrails” gave me the best results.  Anyway, this image will always remind me of sitting in the road with the camera doing its work, enjoying a couple of good beers with Steve and listening to wildlife: coyotes howling on three sides of us in the distance, Henslows Sparrows singing like it was the middle of the day and a presumable deer that walked just off the road past us less than 10 feet away.  I have no idea if the deer could see us or knew that we were there.

IMG_5566

I say with all sincerity that I would trade the benefits of living in a large metropolitan area just to have the privilege of viewing night skies like this on a regular basis.  How did we agree to give this up?  I guess this issue ranks up there with the question of my foreskin.  Nobody ever asked me and I’ll likely never have the opportunity to get it back. ;=)

Anyway, this was one hell of an experience and I can’t wait to give it another try.