However then I went for a 12" deep barrel and discovered that focus breathing seems to make this tricky, if not impossible. Here are the first and last photos in the focus bracket set. The focal length changes so substantially that at least Photoshop has no idea how to align the stack. Is there a solution for this? E.g., are internal-focus macro lenses immune to focus breathing? Or is there a practical means of merging a stack that ends up with a significant range of focal lengths?