Stitch Images Together

Images of Cooper's Hawk to be Stitched Together. Photo courtesy of Mike McDowell.

Edge distortion is a big problem when digiscoping larger birds such as owls and other birds of prey. One thing that works to the digiscoper's advantage is that, unlike most songbirds, large birds of prey are often stationary. This presents a technical solution that I've found to be effective. Because the sharpest area of the field of view is the middle, I will take one exposure by centering near the bird's face (Image A) before quickly taking another shot of the rest of the bird's body (Image B). These two images are loaded into Adobe Photoshop and carefully stitched together.

Creating seamless images

Though the process of stitching images together is somewhat tedious, with enough practice you can make your images look seamless:

Stitched Image of Cooper's Hawk. Photo courtesy of Mike McDowell.
  • Load the two images to be stitched into Adobe Photoshop and then create a third image that is twice the size as one of the single images.
  • Select and copy each image and then paste it into the large image. Image A is automatically made into one layer and Image B becomes a second layer as they are pasted.
  • Use the move tool to overlap the images.
  • Next, adjust levels and match the brightness of the intersecting edges as closely as possible.
  • Using the eraser tool, remove image data along the edge from the upper layer, revealing data from the lower layer. In detailed areas you often only need to erase a small portion to blend the two images together. In open areas, like a blue sky background, you might have to erase more area for the blend to be successful.

Depending on the stitch, an added bonus is that the final image's physical print size will be increased. This technique may seem like a lot of effort, but it's pretty easy once you get the hang of it. Remember to think of this when you're in the field and you have a fairly cooperative perched bird that's too large to fit into the sharp-zone of your field of view. Take upper and lower shots and let the magic of Adobe Photoshop do the rest!

Article and photos contributed by Mike McDowell, an avid digiscoper, amateur naturalist, and Eagle Optics employee. Visit Mike's Birding and Digiscoping Blog.