Eclipse Report, Part 2


https://www.youtube.com/watch?v=3a0nZAFfcEI&feature=youtu.be

The above video is one of three that I captured during the eclipse.  This one uses a “white light” solar filter and is fairly wide angle, as it was intended to show the extended corona (and some nearby stars) during totality (more on that later).  The second was shot with my H-alpha solar telescope and is much more “close up”.  That one needs a lot of processing, since each frame of the movie requires processing hundreds of frames to produce a good image.  The third one is essentially useless.  In the not to distant future I hope to add some frames during totality to the middle of this first sequence.

Which brings me to the sad story I mentioned in part 1 of this report, of which the final message is that I failed to capture anything during totality.  I totally failed totality.  A great many things went wrong, including some fairly complex technical issues, and some silly mistakes.  But in the final analysis, I have to say that all the root causes could be described as “personality disorders”.  In particular, stubbornness, sloth, and arrogance all played a role.  Despite having no experience in photographing a solar eclipse, and having done little preparation and NO testing, I was convinced that I could manually run three systems and capture everything I wanted.  The fact that things started failing just an hour before the start of the eclipse should have radically changed my plans and made me focus on getting the essential shots I wanted.  Instead, I just simplified the plan a little bit.  The crunch time in this plan is that before the start of totality I had to re-program the cameras and intervalometers to shoot rapid sequences of bracketed exposures.  I didn’t give myself enough time to do that, and when the first step of that processed didn’t work as expected, I stubbornly continued to work on it until it was right.  Totality lasted 92 seconds where I was, and it was the shortest 92 seconds of my life!  By the time I got the camera working, totality was over.  I never got to the second camera, or even got to remove the filter from the first.  I did look at the eclipse several times during totality, but it would have been much better to have abandoned photography at the first sign of trouble and just watched the eclipse closely.  This is exactly what most of the experts warned about!

So now I’m thinking about the 2024 eclipse that goes from Mexico to New England, and the one in 2019 that goes across South America.  But more importantly, I’m working with some fellow astro-photographers on putting together the best possible images from multiple sources.  So there will be some eclipse photos in my 2018 calendar, and I hope to contribute to the effort by processing the images, but my image captures will be limited to the partial phases.

Before the eclipse, this year’s star party also provided some excellent skies, despite a huge music event just a few miles away that produced a lot of light (and a bit of noise).  Fortunately, they used lasers only one night, and it was cloudy then anyway, so I wasn’t imaging.  On other nights the sky was very dark and extremely steady (low atmospheric turbulence).  In fact, it was the best skies for imaging that I have seen in a very long time, and made me wish that I had brought the “big” telescope (an 8″ SCT) to photograph the small galaxies that are usually hopeless through the active air currents at Wa-chur-ed Observatory.  Then again, most of those galaxies were low in the northwest – right above the nearby light pollution.  So I just photographed a few targets that would most benefit from the enhanced sharpness in my refractor telescope.  And I’m going to show them to you here cropped more tightly than I normally would, to take advantage of that sharpness.  First is M13, the Hercules Cluster:

It still needs some clean-up, but this is by far the best capture of M13 I have ever done.  In addition to the great seeing conditions, I shot and processed this a little differently from my usual procedure.  Since my telescope has a bit of chromatic aberration, luminance frames (which include all colors in a single, monochromatic image) are less sharp than the separate red, green, and blue frames (each of which benefits from having the telescope focused specifically for that filter).  So I decided to shoot only RGB, being careful to keep them all well focused, and shooting lots of frames.  And then I had an idea:  I created a “synthetic” luminance image by selecting only the very sharpest individual exposures from each color filter and stacking them together – something you would not normally do.  With a suitable number of exposures from each filter included, this L frame would accurately reflect the brightness for each pixel, but would be sharper than the full RGB image.  The L frame is then applied over the color image using a “blend mode” that uses the brightness from the L channel and the color from the RGB channels to define each pixel.  It seems to have worked, although the difference in sharpness is pretty small.

My second target was M33, the Triangulum Galaxy:

As with M13, I have photographed M33 before, but never got it this sharp.  This is also a fairly tight crop, but not quite so much as M13, as this is a much larger object.  I didn’t use the synthetic L procedure here, although I may go back and try it later.  I did capture some hydrogen-alpha data and used it to brighten the red channel to highlight the hydrogen regions.

The third target I captured is the Iris Nebula, which I have been working on for many years.  Seeing was excellent for this target as well, but the sky was a bit hazy.  If it turns out that this data is good, I will combine it with older images of the Iris to try to get an enhanced version.

The images from the solar telescope might be interesting as a video.  It would show more detail in the Sun’s surface, and perhaps even show some motion in this texture as the Moon slowly covers it.  But I will probably focus on trying to put together a good image of totality from multiple frames.  Stay tuned!

 


About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.

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