Exploring the very first galaxies is one of the major contemporary problems in astrophysics. We do not know when the first galaxies formed, nor how their formation occurred. This problem can be addressed best through deep imaging observations, particularly with the Hubble Space Telescope (HST) Frontier Fields (HFFs). In this study, we detect and examine the objects behind HFFs lensing cluster MACS0416-2403 and its parallel field. We present a photometric study of distant z > 5 galaxies by subtracting the massive galaxies from these clusters, allowing for a deeper and cleaner detection of these faintest systems. From this, we measure the luminosity functions, stellar mass functions and star formation rates for the faintest galaxies at z > 5. In particular, we will discuss how these results reveal new information on the faint-end of the mass function as well as the UV emission from the faintest galaxies at high-z.