One of the primary reasons I bought a full-frame camera was because of the low light capabilities and the ability to shoot at a high ISO level without the quality of the picture being compromised. I can say the Nikon D750 kicks some serious ass when it comes to this compared with my Canon Rebel T3i where the images wouldn’t have been nearly as clean. We are heading to Africa at the end of this year and I wanted to be able to shoot wildlife on the edges (when the light is poor) and keep the images sharp and not overly noisy. I didn’t think it would be useful for shooting Chicago architecture but it paid off when up on the top level (94th floor) of the Hancock Center and the images were all coming out blurry at ISO levels of 100, 200 and 400. For this picture the shutter only had to remain open for 1.3 seconds versus 15 seconds or more at lower ISO levels. I’m not sure if the building was swaying or if people were tapping the makeshift tripod I assembled (since ‘normal’ tripods are not allowed) but having the ability to capture the same quality image 13 seconds faster was a huge advantage.