Lunar Eclipse

[Diane Miller]

I'm still on the road with my laptop but going to take a chance on the processing with it.

The cloud forecast at home (NW of San Francisco) looked bad and I decided Joshua Tree NP looked a lot better. Being quite a bit farther east, that also meant the moon would be a little higher without so much air in the path, so I headed out for a 2-day drive to this very cosmic location, with dark skies at 4000-5000 ft.

All was good until yesterday afternoon when high clouds loomed to the north. I set up, hoping for luck, and got it! The moon was behind some thin clouds for a while but the middle of the eclipse was clear, as far as I could tell.

I wanted to get the lowest ISO to get the best details, so I needed to freeze the motion of the dim moon at 600mm. I set up my Astrotrac on lunar tracking mode, with the Canon 600 mm II and the 7D Mk II. It wasn’t dark enough to do the requisite polar alignment (lining up on Polaris) so I had to use my iPhone compass to aim the tracking axis north. After using the compass successfully for years, and many times yesterday to find where the moon would be from various locations, it started doing very strange things just as I was aligning. Powered the phone off and back on and it worked long enough to align, then went crazy again. (Maybe the desert heat got to it?) But the tracking was fortunately very good. Don’t know if it shows here but the stars are very slightly elongated due to the difference in the motion of the moon, which I was tracking, and the stars.

This is a composite of two exposures, due to the brightness gradient across the moon. (This eclipse was deeper in the earth’s shadow than most, so this one was easy.) The moon was dim enough that the stars showed beautifully. I had the best results at ISO 800, 1 to 4 sec exposures at f/4, near mid-eclipse. I was hoping to be able to get down to ISO 100, but a breeze made the shorter exposures sharper.

It is so cool to watch the skies get dark in a lunar eclipse and all the stars come out as they do in a new moon.

[William Dickson]

Very nice Diane. I like this a lot. It was well worth the effort you put into it.

Thanks for sharing.

Will

[Rachel Hollander]

Hi Diane - it shows the color really well. I think the moon could use a bit more sharpening.

TFS,
Rachel

[gail bisson]

This is lovely Diane.
The color is beautiful and to my eye it looks really sharp.
Love all those stars.
May I ask why you needed to do Astrotrac and need to be lined up with Polaris?
I am thinking I did not do this correctly as I just set my tripod up and aimed at the moon?!!
Gail

[Morkel Erasmus]

It works so well with the stars, Diane!
I agree that the moon could use some sharpening and finer texture - perhaps too much noise reduction on it?

[Diane Miller]

Thanks, everyone1 Just hitting the road for the drive back -- will reply tonight if I have time, else when home.

[Warren Spreng]

Looks great Diane, nice color on the moon and I don't believe sharpening is necessary on the moon. The full moon is really difficult to get much more than the shading that you show nicely. Is your black point clipped on the sky? That would be my only minor nit but the black sky works with this image.

[Don Railton]

Think its all been said Diane... Well done. Agree with sharpening, love the stars...

Don

[Diane Miller]

As an astrophotographer, Warren has the correct perspective (or at least the reality-based one). Shooting the eclipsed moon is a very different proposition than the illuminated moon. It is incredibly dim and low contrast. Think of shooting a mountain in bright sun and then again quite a while after sunset. It just won't be possible to pull the detail out of the low contrast low-light scene that you get in the sunlit scene, even if you expose well to the right. And what you can pull out will be with a penalty of noise.

I'd love to have more detail and sharpness, too, but this represents the reality of what can be done without an extremely sophisticated telescope and tracking mount with a CCD camera. The raw capture was "sharpened" in Lightroom with the Clarity slider, and again in PS with Nik's Detail Extractor and then with the Low Pass filter. And of course all this necessitated trying to balance some careful NR. It's a very small and shallow sweet spot.

And the moon was fairly low in the sky from any location I was willing to go to, and that much thickness of atmosphere is a huge factor. It is rarely clear anywhere. (My husband was 2/3 of the way across the county an antique fly-in so my usual transportation was compromised to driving.)

Gail -- I set up the Astrotrac to follow the movement of the moon in hopes of getting the ISO down to 100 or 200. That would be in the range of a 5-10 sec exposure, or maybe more, which would show the movement of the moon at 600mm on a fixed tripod. A slight breeze made the longer exposures a little less sharp, so I wound up using an ISO 800 set. But I may decide I can do better with a lower ISO set when I have time to look more closely.

Warren, the sky is clipped here, to reduce some noise. It may be less so when I reprocess more carefully, but I think I'll want to leave it black. (This is a "dark sky" location.) The sky was masked out for all the stretching of the moon.

Here's the rig, with the 300 on it.

[Warren Spreng]

As an astrophotographer, Warren has the correct perspective (or at least the reality-based one). Shooting the eclipsed moon is a very different proposition than the illuminated moon. It is incredibly dim and low contrast. Think of shooting a mountain in bright sun and then again quite a while after sunset. It just won't be possible to pull the detail out of the low contrast low-light scene that you get in the sunlit scene, even if you expose well to the right. And what you can pull out will be with a penalty of noise.

I'd love to have more detail and sharpness, too, but this represents the reality of what can be done without an extremely sophisticated telescope and tracking mount with a CCD camera. The raw capture was "sharpened" in Lightroom with the Clarity slider, and again in PS with Nik's Detail Extractor and then with the Low Pass filter. And of course all this necessitated trying to balance some careful NR. It's a very small and shallow sweet spot.

And the moon was fairly low in the sky from any location I was willing to go to, and that much thickness of atmosphere is a huge factor. It is rarely clear anywhere. (My husband was 2/3 of the way across the county an antique fly-in so my usual transportation was compromised to driving.)

Gail -- I set up the Astrotrac to follow the movement of the moon in hopes of getting the ISO down to 100 or 200. That would be in the range of a 5-10 sec exposure, or maybe more, which would show the movement of the moon at 600mm on a fixed tripod. A slight breeze made the longer exposures a little less sharp, so I wound up using an ISO 800 set. But I may decide I can do better with a lower ISO set when I have time to look more closely.

Warren, the sky is clipped here, to reduce some noise. It may be less so when I reprocess more carefully, but I think I'll want to leave it black. (This is a "dark sky" location.) The sky was masked out for all the stretching of the moon.

Here's the rig, with the 300 on it.

Nice looking set up Diane! Yeah, I think with this composition that the black sky looks good with it. Have you tried some Milky Way shots with this set up from a dark site yet? I'll bet you could get some nice vistas with it.

[Diane Miller]

I have -- and a 17mm tracks a lot better than a 600! I posted one in Landscapes a while back.

Have some astro sequences stacking up to process, if I ever slog my way through PixInsight. All low-hanging fruit, though, with 600 being the max I can do. (Putting a 1.4X on it really shows up that camera lenses weren't designed for stars.)

[Warren Spreng]

I have -- and a 17mm tracks a lot better than a 600! I posted one in Landscapes a while back.

Have some astro sequences stacking up to process, if I ever slog my way through PixInsight. All low-hanging fruit, though, with 600 being the max I can do. (Putting a 1.4X on it really shows up that camera lenses weren't designed for stars.)

if you figure out Pixinsight let me know, I have tried to get into it half a dozen times and my photoshop trained brain just can't get the hang of it! Yep, the longer the FL the more tracking errors show up!

[Diane Miller]

I've tracked very well with the 600 for 25 sec (haven't tried longer) but that was with real polar alignment. Having to do it in daylight with a bloody compass is just not fair.

Look up Jim Morse's web site, and Google Harry's Astro Shed. There is a PI forum that can be helpful but is usually advanced stuff. Tutorials are sadly lacking but a book is said to be in the works. Jim has an excellent cribsheet that he'll send you for the asking, but you have to get partway into it to even understand it. My notes are beginning to resemble PI for Dummies. I'd send you a copy if you're at that stage of interest, but it's very much a WIP.

I have survived (barely) a graduate level course in quantum mechanics and it is a walk in the park compared to PI. But at least no equations are involved.

[Jerry van Dijk]

Thanks a lot for posting this wonderful capture of the eclipse Diane! I must confess that I was hoping you would, because I was too lazy to get out of bed (busy week at work) to go and look.
The dark sky and bright stars realy complement the blood moon. I do think you could get better sharpness on the moon. It is sharp enough, but it looks like sharpness with a large radius, sharpening especially the coarser structures on the moon. I think you could get better results with a lower radius (0.6 to 0.8).
I still see quite some reddish color noise in the blacks, or are those faint stars?

[Diane Miller]

Thanks Jerry! I didn't use the traditional sharpening methods. I used a slight amount of Clarity in LR, along with some judicious Shadow and Highlight moves, then in PS some NR (Nik Dfine), Detail Extractor and High Pass "sharpening." This was processed on my laptop that night (after a few beers and a good Mexican dinner in celebration) and when I got home on a real monitor I saw I had overdone the High Pass filter, in particular -- so you're very right about a radius, but not the usual one.

Here is a re-do, more restrained and more realistic. This image had major noise issues, probably due to the heat -- it was very hot at about 90 degrees, which is not the traditional environment for astro photography. (I'm usually freezing to death.) So now I have darkened the sky to remove the red flecks you're seeing.

You didn't miss a lot by not getting up -- the visual appearance was quite unspectacular. Our eyes don't respond well to color in dim light.

[Jerry van Dijk]

RP looks great Diane!

[Warren Spreng]

Have you tried taking Darks and subtracting them from your image? That may help clean up the noise you are seeing as well.

[Diane Miller]

I've just made a Bias master in PixInsight -- wonder if that would help? I've never seen noise like this is any previous eclipse or other AP image, and most were shot at ISO 1600. But in much cooler temps.

I've heard enough about issues with Darks for Canons (which do some processing on the sensor that can make normal Dark correction actually work against you) that I haven't tried using them yet. But making a Curves adjustment layer using the mask just for the sky, and pulling the left end for the Red and Green channels just enough to the right to kill the little spots has worked well. Lightroom (and ACR) automatically removes any hot pixels so that isn't an issue.

[Andrew McLachlan]

Hi Diane...the repost does it for me...lovely...I wanted to get a few of these images too but we had heavy cloud cover that night :(