If you read a book on linear perspective the examples will present a sight line ( sometimes referred to as the “Horizon Line”) parallel to the bottom of the picture( also known as the ground plane). Its illustrations, like most paintings and photos, sit squarely and on the level. Most pictures do not intentionally challenge where is “level.” Unless, the artist wishes to induce an odd sensation of vertigo or uncertainty in which case we may find the picture plane can be tilted. If the plane is tilted and curved along with the rest of the picture then, we may feel a peculiar sense of motion and instability. The picture becomes more dynamic and, ( too a few ) more troubling because, even a static , painted visual reminder of instability may induce symptoms of vertigo. The recipe is simple. Tilt and curve the horizon and, align the rest of the picture with the tilt and curvature. The viewer will either find this fun like skiing or riding a rollercoaster or, disconcerting. Either way, the viewer will be reminded of the effects of gravitational instability. Here, I present you with three gentle examples of tilted curvature and the attendent suggestion of movement. In the first image, an interior in the Met Museum, I simply tilted the entire image. In the second image I have curvilenear distortion as well as tilt. In the third image I have tilted curvature and a vertiginous prospect.