General relativity predicts that light can enter into orbit around a black hole, producing photon rings. Analyzing images of the photon rings and the accretion disk of a black hole can thus give us a better idea about the implications of GR and black hole structure. For my project, I review the basis of the principles involved and discuss how we can test GR by means of an example Schwarzschild black hole with a thin accretion disk. I present the output of a simulation I created in Mathematica that uses ray tracing to produce images of photon rings and accretion disks representing what we would observe in this geometry, and find that my results are consistent with those first proposed by Luminet in1979. Accounting for the fact that astrophysical black holes are actually considered to exist within the Kerr geometry, I examine the role of similar images in more thorough analyses, notably the recent Event Horizon Telescope images.