Lightroom is a photo editing software that lets you create and manage photos. You can use it to make photos look better, but you can also use it to make them look worse. To see how photo ratings are calculated in Lightroom, you first need to understand how Lightroom works. Lightroom calculates the rating of a photo by adding up the votes of all of its users. The higher the vote, the higher the rating is. To get a good rating, a photo must be well-reviewed by other users. To get a good review, it must be at least 4 out of 5 stars. To get a great review, it must be at least 5 out of 5 stars.