A light field, which is often understood as a set of dense multi-view images, has been utilized in various 2D/3D applications. Efficient light field acquisition using a coded aperture camera is the target problem considered in this paper. Specifically, the entire light field, which consists of many images, should be reconstructed from only a few images that are captured through different aperture patterns. In previous work, this problem has often been discussed from the context of compressed sensing (CS). In contrast, we formulated this problem from the perspective of principal component analysis (PCA) to derive optimal non-negative aperture patterns and a straight-forward reconstruction algorithm. Even though it is based on a conventional technique, our method has proven to be more accurate and much faster than a state-of-the-art CS-based method.