Tuesday, November 23, 2021

Rough Draft: Timelapse of Longest Lunar Eclipse in 1000 Years

As mentioned in my last post, I used my Nikon D750 DSLR mounted on a Sky-Watcher Star Adventurer tracker to capture about 5 hours of the partial lunar eclipse. Here is a preliminary time lapse video. 

This sequence is just from the shots exposed for the sunlight face of the moon. I'm working on another sequence with full lunar surface, blending shots exposed for sunlight and shadow. The blended shots will showcase the redness of the lunar surface at mid-eclipse. They will also include the Pleiades and a tighter crop. 

The movement of the moon in this sequence is not due to its movement across the sky but the moon drifting out of center-frame due to the polar alignment of tracker being a little bit off. I'm still working on a process to re-align the sequence and to rotate the view for a more natural orientation of the sky.

When watching the video, be patient as there are a few seconds in the middle where it goes black. The shots used in this video were taken at f/6.3, 2500th of a second, ISO 800. It turns out that was slightly underexposed for a sunlit lunar surface during the phase where the Moon was mostly eclipsed, I missed capturing the portion of its surface still reflecting sunlight so nothing shows up.  

More to come...


BTW, for a better view, select full screen (box icon, lower right) when playing the video. 



Monday, November 22, 2021

Chasing A Partial Lunar Eclipse and the Seven Sisters

In the early morning hours of November 19, 2021, a lunar eclipse began. As a partial eclipse, it normally might not have been noteworthy. What brought a lot of media attention about this one is that it lasted just a shade over 6 hours. It's been 1000 years since the last time a lunar eclipse lasted that long. 

The timing for this eclipse is such that the Moon was almost at apogee, the point where it is furthest from the Earth in its orbit, and since a body in orbit moves slower the further it is from the body it orbits, the Moon spent more time in Earth's shadow. It also meant that the Moon was smaller in appearance so this was the opposite of a "Super Moon". 

The other interesting thing about this lunar eclipse is that the Moon is within a few degrees of the collection of stars known as the Pleiades or the Seven Sisters. As both were high in the sky during most of the eclipse, the cold dry air we had in North Texas that night made for great viewing. 

Initially, my plan to capture the eclipse was to shoot with my Nikon D750 using the longest lens I have and the Star Adventurer sky tracker to capture shots of the lunar face throughout the night to create a timelapse video. However, given the close proximity of the Pleiades, I decided to shoot with a shorter lens and include it in the view. 

I won't go into the technical details but given this was really the first time I had used the Star Adventurer for tracking more than a few minutes, I shot a bit wider view than I probably needed to so the Moon is rather small in the frame. The bad news is that the tracker was a little off and so the Moon didn't stay centered in the frame. The good news is that with the wider view, both it and the Seven Sisters were in-frame throughout the 5 hours of the eclipse I captured. 

Here is a frame from about mid-eclipse. I'll post more as I get further through post-processing all the images.