Trevor Raab, Interdimensionally, 2015.
The stars are aligned: all the signs are pointing to 2018 as the tipping point for in-game photography, that is, for the transitioning of this practice from the (relative) underground to a more institutionalized context.
Below are some of the key factors that are contributing to this phenomenon:
Commercial efforts to incorporate in-game photography into the gameplay by dramatically expanding the tools available to the players are increasing. In this regard, nVidia is the clear market leader (see The Instagrammification of Gaming for more details). Moreover, photo modes are becoming more versatile, flexible, and powerful. Consider, for instance, Gran Turismo GT' Scapes and even the Shadow of the Colossus remake.
Institutional: Exhibitions featuring game-based photographs are growing, in quantity and quality, all over the world. 2017 has seen, among others, Simulacrum (both in the Netherlands and Germany), Screen Knowledges in Los Angeles, and, in 2016, SITUATIONS_PLAY (2016). More are planned for 2018.
Journalistic: More in-depth articles are appearing on "traditional" photography magazines and blogs. Consider, for example, Erik Kroes for PhotDev. or B&H Photography, which produced a terrific podcast on this topic last Summer:
Academic: several researchers have been investigating the phenomenon for the past few years, including Cindy Poremba, Marco De Mutiis, and Sebastian Moering, among others. De Mutis, the Digital Curator at fotomuseum in Winterthur, Switzerland, has recently published a terrific essay titled Photo Modes as a Post-photographic Apparatus. Moering and DeMutiis are curating the indispensable In-Game Photography Blog. The excellent Video Game Tourism website is featuring a series of interviews with artists and practitioners. Consider the recent conversation between Eron Rauch and Kent Sheely.
Publishing: in-game photography books are also on the rise. Consider, for instance, COLL.EO's Boring Postcards from Italy (2017), M. Earl Williams' 26 Gasoline Stations in GTA V (2017), Trevor Raab's Interdimensional (2015) and more.
And, last but certainly not least, the number of practitioners has greatly expanded in the past few years, but the list is way too long for such a short post. Keep an eye on these pages for more...