|Posted by Joel on September 15, 2013 at 11:40 AM|
This tutorial is a follow up to my previous tutorial on shooting star trails. If you have yet to read that tutorial I suggest doing so now. This will pick up where that left off, the editing of a star trail photograph. As I ended the last tutorial I mentioned that most star trail images will have airplanes, and other distracting elements in them. This tutorial will teach you one trick to removing these objects without diminishing the actual image. For this tutorial I will be using this shot taken with a Canon Rebel XS, and a kit 18-55mm lens:
The shot settings for this image are:
Shutter: 30 seconds (82 images stacked)
Focal Length: 18mm
Part 1: Loading the images
In the last tutorial I taught you how to load the images into a stack. This is critical for editing the image as well. For this tutorial I will not detail the process of loading the files, I will merely show you what this image looked like when I loaded the files into the stack. Here is what I saw when I first loaded the images to Photoshop:
As you can see, the image has many planes flying through the frame. Also, the tree is very bright, and it does not look natural. If you scroll up to the final product you will see that the tree looks much better than it does in this image. The reason for this is that I triggered an external flash in the first image. I was hoping to light the tree, and use that as a way of avoiding a silhouette, but a car's head lights gave a much nicer look later in the shoot. The car lit the image from the side, and the florescent headlights were not the same tone as the flash i used, and that caused the distracting light on the tree. This image may not be as appealing as I had hoped, but it is imperative that I save a copy of this image to use later.
Part 2: Removing the distractions
The images are loaded into a stack on the right hand side in Photoshop, and next to each image there is an eyeball. This eyeball tells you that the image is visible in the stack. For this step you will go through the stack and click the eyeball on each shot with a distraction in it; this will take the distracting shot from the final image. However, it will also take the stars out of each shot that has a distraction. This will make the stars look choppy, and create a very distracting sky. Here is what this shot looked like with the distractions removed:
You can see the missing sections in the stars, but you can also see that the tree looks better, and sky is free of distracting airplanes. This is what we want to see. Next you will save a copy of this image.
Part 3: Blending the shots
You now have two saved images. One with all the distractions, and one with the distractions removed. The next step is to load these two images into a stack. You can either use the feature in the file tab, or you can copy and paste the images into a new document in Photoshop. Either way, you will want to make sure that the first image (the one with all the distractions) is on top. Next you will apply a layer mask. To do this in Photoshop click:
Layer:Layer Mask:Reveal All
After making sure that you are editing the layer mask and not the actual image click your brush tool on the left hand side of the screen, and change the foreground color to black. This will allow you to erase the top image and allow the bottom image to show through.
Now you will simply draw over the distractions allowing the second image without the distractions to show through. Remember how the stars looked in the second image? Since we are only allowing the second image to show through where the planes were we keep those stars from showing. Here is the result:
Part 4: Final Touch Up
This image is looking much better that did when we started, but it still doesn't pop. For this I just gave a simple adjustment with the Shadows and Highlights tool. Now the image has a better glow to it, and I am satisfied with calling this a final product: