Photographic composition is often taught as alignment with composition grids—most commonly, the rule of thirds. Professional photographers use more complex grids, like the harmonic armature, to achieve more diverse dynamic compositions. We are interested in understanding whether these complex grids are helpful to amateurs. In a formative study, we found that overlaying the harmonic armature in the camera can help less experienced photographers discover and achieve different compositions, but it can also be overwhelming due to the large number of lines. Photographers actually use subsets of lines from the armature to explain different aspects of composition. However, this occurs mainly offline to analyze existing images. We propose bringing this mental model into the camera—by adaptively highlighting relevant lines to the current scene and point of view. We describe a saliency-based algorithm for selecting these lines and present an evaluation of the system that shows that photographers found the proposed adaptive armatures helpful for capturing more well-composed images.