Let's talk about perspective. Any image rendered with perspective enabled will show convergence, or vanishing points, for all parallel lines. In most cases that is desired since perspective helps us understand scale and proportion, and it’s a realistic interpretation of our vision and photography. Perspective can be described as one-point, two-point or three-point perspective.
However, since that third point of perspective can be distracting, particularly in architectural shots, it's not always desired. Looking up at a tall building shows the convergence of the vertical lines towards a vertical vanishing point. When using KeyShot, you introduce 3-point perspective whenever your camera is tilted up or down (set by the Camera tab, Inclination slider).
A photographer will use a Shift Lens to create the effect of all vertical lines being parallel, shifting it to two-point perspective. It does this by pointing the camera directly forward, and shifting the camera’s viewing plane up or down to control what’s visible. The camera is still at the same height, but it is shifting the viewing plane to get the desired result. In KeyShot, it happens exactly the same way.
This technique is also used with product photography and renderings--objects that are side by side will show less vertical distortion when a shift lens is used. It’s especially apparent with rectilinear forms such as mobile devices and large appliances. The image below cycles through two scenes, the only difference is the use of a Shift Lens in order to make the composition look better.
So, how do we use the Shift Lens feature in KeyShot?
- In the Camera tab, select Shift under the Lens Settings dropdown menu.
- Press the Estimate Vertical Shift button. This will set your camera facing forward and calculate a starting Vertical Shift value.
- Adjust the Vertical Shift to your liking. Note: Don’t move the camera using your mouse; control the movement using your Shift value.
That's it! Now you can use the Shift Lens to get more control over your images and compositions.