The Nikon D750 comes with Exposure Preview OFF by default. Here is a quick video tutorial on how to turn it on while in Liveview mode. Having Exposure Preview on my D4 but not my D600 was confusing. So glad the D750 has it! 1) Press Lv to to turn on Liveview 2) Press the italicized "i" button on bottom left 3) Scroll down to last option which is Exposure Preview. 4) Select ON