While lens flare was traditionally created in-camera, the advent of digital technology, often results in creating lens flare in post. Though this approach is often quicker, it does have a tendency of being over-used. Any JJ Abrams fan can surely attest to this!
However, by creating lens flare in-camera to be used in post, the results can be more organic, and more controlled at the same time. We created these flares in-studio with this setup.