Composite Meteor Shower How To

http://www.youtube.com/watch?v=u7JVwSX1iAg&feature=player_embedded

In preparation for this meteor shower I have finally put together a tutorial to show how I created the composite image 'Snowy Range Perseids'.

Meteors originate from what is called a 'radiant' this varies based upon the meteor shower and is named after the constellation the radiant is closest to. You can find more information about each meteor shower at SeaSky and EarthSky.

This radiant changes position in the sky throughout the night as the earth rotates. To have a more pleasing image we must rotate each meteor to match the radiant of one of the images that we will use as a base. The video below demonstrates the technique.

This method is best explained in the video above, but if you can't view on YouTube for some reason, here is the written description.

To start with I had to identify each image that had a meteor from the hundreds taken over the entire night. I did this in Lightroom using the color flags to identify each shot with a meteor.

Once I had them all identified I selected all 23 shots, right clicked, Edit in > Layers in Photoshop. Once opened in Photoshop I changed the blend mode of the layers to lighten to easily identify where Polaris/North Star was located. This is the point we need to rotate around to correct the meteors to their radiant.

I mark this point using the custom shape tool and placing a target symbol. Then I turn off all but the base layer and 1 additional layer. With the correct layer selected I activate the Free Transform tool, I then change the rotation point to the previously placed target.

Now I rotate the layer until the stars align and finish the transform. Then I apply a reverse layer mask by Alt+Clicking on the new layer mask button.

Then I zoom into the meteor, brush on the layer mask using white as my foreground color to show the portion of the layer with the meteor. Clean up any additional stars by switching your foreground color to black and painting them out on the layer mask. Repeat for each layer, delete the target when finished and flatten the image.


For the 2012 Perseids meteor shower I knew I wanted to create a unique nightscape, to achieve this I needed dark skies free of light pollution and a moonlit landscape in the perfect orientation with the constellation Perseus. After many hours of scouting I found my location in South central Wyoming in the Medicine Bow National Forest, an area known as 'Snowy Range'. The skies in this area were some of the darkest I have seen in my lifetime, the stars shined with a brightness that is indescribable, and the milky way clearly visible to the naked eye. I set up my Nikon D700 to capture 30 second exposures at ISO 3200 with an aperture of f2.8 on my Rokinon 14mm lens just as twilight was fading away. I spent the next 7 hours taking continuous photos until the sun rose. I captured 22 meteorites and an iridium flare, in Photoshop I overlaid all of the shots with meteors, rotated them based on Polaris to correct their orientation as Perseus moved through the night, then masked out everything except the meteors to reveal a stationary field of stars. To complete the composite I added one frame from sunrise to brighten areas of the foreground because the moonlight was blocked by a large group of trees for the entire night. An incredible night to not be forgotten.