I usually set my D800 to ISO100, f14 and 1/200 for when I'm in the studio. Last week I had a shoot, and I accidentally knocked it 1/250. That should be fine since the D800 can sync at that speed, but I'm going through the photos now and I have a horrible line in some of the photos from the second curtain. It's more obvious in some pictures than others. In a few it's just a slightly dark gradient at the very bottom of the image, but in others there is a pure black line. Is this an issue with my camera, or has Nikon exaggerated the sync speed in the specs? If I wasn't shooting with a white background I might not have noticed it in some images, but in others they are completely black at the bottom.