When Sony announced the 61MP a7R IV this week, both presenters were quick to say that the camera’s full-frame sensor “rivaled medium format” thanks to its combination of resolution and dynamic range. But was that engineering truth, or marketing speak? Photographer Matt Granger decided to find out. Granger happens to have the Fuji GFX 50r, Hasselblad X1D II 50c and Sony a7R IV in his studio right now, so he decided to do a quick shoot with a non-model and…