How to create an HDR moon composite using Photoshop
This spectacular image depicting the crescent moon moving through space is one of the most challenging I’ve ever created. Here’s a quick guide to how I did it, and how you can capture a similar shot yourself.
Setup
Hundreds of images of the moon were captured at 600mm, f/6.3, and a variety of exposure times ranging from 1/20s to 1/200s, and ISO values from 200 to 12800.
Stacking
First, I grouped together frames with matching settings and stacked using software called Autostakkert (https://www.autostakkert.com) to reduce noise.
- 9 frames at 1/100s, ISO 320
- 9 frames at 1/100s, ISO 2000
- 9 frames at 1/20s, ISO 2500
- 9 frames at 1/40s, ISO 2500
- 9 frames at 1/100s, ISO 6400
- 9 frames at 1/20s, ISO 6400
- 18 frames at 1/30s, ISO 12800
- 36 frames at 1/80s, ISO 12800
Secondly, I put those stacks together in Photoshop using luminosity masking to create a single composite image. (Easier said than done!)
Restoring shadow detail
I’ve now pulled as much detail as I can from the earthshine but still lacking some definition. I carefully overlaid and masked one of my prior full moon images, also captured at 600mm, at 50% opacity. (Note: the alignment is not perfect to a trained eye but very close.)
Glow
Restoring some natural looking glow was the easiest part of the process. For this I used the stack of images captured at 1/20 seconds and ISO 12800, then overlaid the moon above and adjusted the global contrast.
Adding the star trails
Capturing star trails at 600mm was a step too far for my gear. At this focal length it was hard to get a clean trail even with stabilisation, a sturdy tripod and a relatively windless night. Instead I opted for 75mm and cropped heavily to roughly match a 600mm frame.
Compositing
The star trails were captured at 75mm, f/3.5 ISO 800 and 10 second exposures for a total of 272 frames, so around 45 minutes of exposure time.
Compositing with the existing elements and elevating the shadows brings me very close to a completed image.
Finishing touches
Finally adding some vibrance, glow, colour correction, structure and contrast using
Luminar Neo to complete the image.