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special action needed for recent lunar eclipse-- having issues!

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Jon Iverson
special action needed for recent lunar eclipse-- having issues!
on Oct 1, 2015 at 4:11:18 pm

I recently used a small telescope and my DSLR to take nearly 1500 images of the recent lunar eclipse with the intention of making an AVI animation later. I have run into a major difficulty, however: because my telescope had a higher focal length than I anticipated, I was unable to capture the entire moon in a frame and I had to use two frames consecutively. This has created major problems in trying to create an AVI. I was unable to find a reasonable way to merge each pair of frames (over 700 pairs!) in Photoshop, so I turned to a program called.Autoplano Giga. This seemed to do a seamless merger of each pair, but now I am left with images of differing size, not just the frame size, which I could normally deal with, but the moon as well, so impossible so far to make an AVI.

After trying out various astronomical programs designed for stacking images, I was unable to find any that would rescale just the lunar moon object to equal size in all frames. I finally decided to try making an action in CC. The idea is to select just the moon from each frame, copy the selection, and then paste into a new layer with the background layer being transparent. The result would then be saved as TIFF with transparency, then reopened in CC. I would then use CC to align (and warp) the frames and there wouldn't be a problem because only the moon is being "seen" by CC and not the entire frame since the moon lies on a transparent background. While I could get this to work manually, I have been unable to make an action to do this correctly which is why I turned here.

If someone could point me in the right direction with possible action steps or anything else, I would appreciate it greatly. In a week, I was hoping to present the AVI as part of a presentation I am conducting on astronomy to a local club.

By the way, I initially tried having CC just align the frames once merged in the merger program, but it didn't work. The only way I made progress was to select just the moon and place on a transparent layer and then align. If I could just get the action to work!

Thanks in advance for any help,
Jon


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Kalle Kannisto
Re: special action needed for recent lunar eclipse-- having issues!
on Oct 1, 2015 at 6:03:35 pm

Are the images rotated differently from one to the other?

If not, I would try and approach it with the following action:

1) Trim the image so that only the moon is shown.

2) Resize to a specific size that you want all the moons to be.

3) Copy and paste into the master file. It will automatically paste into the center.

What is the "warping" that you are talking about? (What is warped and why?)


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Jon Iverson
Re: special action needed for recent lunar eclipse-- having issues!
on Oct 1, 2015 at 7:22:21 pm

Thanks for your response, Kalle, but a few questions:

1) How can I specify the action to trim the image so that only the moon is shown when the moon itself might vary randomly throughout the imaging set? The actions I've been able to make so far base trimming on the first image only, to be applied equally to all the others which wouldn't work out since the moon itself is varying in size.

2) How would I get all the moons to be the same size since they differ?

I follow with #3 as I could simply set up a black colored background, but still not sure how to go about 1 & 2.

Warping comes from image transformation, but probably not worth using it here.


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Kalle Kannisto
Re: special action needed for recent lunar eclipse-- having issues!
on Oct 5, 2015 at 6:46:20 pm
Last Edited By Kalle Kannisto on Oct 5, 2015 at 6:48:50 pm

Not having seen an example of how your images look, my theory is:

1) You will have to duplicate the moon layer and add a levels adjustment to get rid of anything other than the moon in the background, then use the magic wand tool without anti-aliasing to select the background, select inverse and crop. Then remove the extra (adjusted copy of original image) layer used for the selection.

Now you should have an image which is cropped tightly around the moon on each side.

2) You can resize the now-cropped image to any specific pixel dimensions. Turn resampling on in the resize image dialog and select pixels as the units.


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