Processing lunar eclipse images


I'm still working on this page. Should have a final version in a week or so.

I like to assemble all of my corrected and aligned images in to one many layered Photoshop file. This allows me to create consistent individual images, time-lapse composites, and time-lapse videos. I simply select the layers I want and render the images in the desired image or video format.

Composite image time-lapse alignment

If you are shooting with an earth horizon frame of reference from a fixed tripod, your images are probably perfectly aligned already. For a still image compoiste time-lapse. The Moon's motion in the sky is opposite the apparent motion of the sky due to the earth's rotation, about 14.5 degrees per hour. With the Moon's angular diameter of 0.5 degrees, this means that image interval you use in your composite must be greater than 2 minutes. I like intervals of about 3 to 5 minutes for a nice spacing. I layer my time lapse composites with one from the beginning or end of the eclipse showing any landscape or architectural elements well exposed. The individual frames of the

If you used a longer focal length lens to capture the eclipse from the Moon's or the Earth's shadow frame of view, you may have to deal with tracking errors even if you used a motorized tracker. There may be manual adjustments to deal with, polar alignment may not be accurate, or the tracking speed may have been off. If I have to correct for these errors, I will create a synthetic alignment layer, to align each frame to. For a Moon centric point of view it will be a small set of features taken with positions taken from a fully illuminated lunar disk image. More than one is needed because a single feature is probably not visible in all images and you may need to correct for rotation erros as well as displacement.

Composites from the Earth's shadow frame of view are more difficult. Your template must track each alignment feature for each time point in the composite as shown in the example below.

Video time lapse alignment

I like to create a video time lapse from still images rather than directly recording video. That way I can create high resolution stills and time-lapse composites as well as render these in higher definition video. All can have HDR that is not achievable with graded s-log video. If the video is from the Earth's shadow frame-of-view, using a dissolve transition between frames taken a couple of minutes apart, smooths the motion of the Moon in the frame.


The exposure for your raw lunar eclipse images was adjusted in discrete steps. If you are making a time lapse image or video you may need to make adjustments to the exposure of frames near those transitions for a smooth natural appearance. It's also common for exposures during totality to be underexposed.


If you shot multiple images at each time interval, you have the option of improving those images by stacking multiple exposures. If the exposures are the same, lucky image stacking even a few images can improve the clarity and reduce noise. I use planetary image stacking programs like AutoStakkert, Lynkeos, and Nebulosity for this purpose. Successful automatic stacking can be difficult during totality because of the low contrast of features on the dim shadowed surface.

During the partial umbral eclipse phases near totality, cameras don't have the dynamic range required to capture the entire face of the Moon. High Dynamic Range stacking can produced spectacular results; shown in the examples below. I use Photoshop for HDR stacking.

Content created: 2019-05-14




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