Here’s our fourth installment of Lytro’s glossary of frequently used terms to help educate and inform about VR, cinematography, digital imaging, photography and light. We’re expanding this glossary as relevant terms arise. Our intent is to add some context about how these things relate to what we do at Lytro. This glossary is a work in progress, so please feel free to share any terms you think might be worthy to add.
Reflections and specular highlights are examples of view-dependent lighting – their location and shape on an object’s surface changes depending on the viewer’s position relative to the reflective object. View-dependent lighting is very subtle to observe, yet is a critical cue in VR for true immersion; without these interactive reflections and highlights, the content can feel lifeless. In both CG and live action VR, only true volumetric techniques like Light Field video can accurately reproduce these critical view dependent lighting effects.
field of view (FOV)
Field of view describes, in degrees, the range of what can be seen of a world at a certain point in time. In cameras, the field of view is determined by the lens, with wide angle lens providing a larger field of view, and a more telephoto lens providing a narrower field of view. In VR head mounted displays, field of view typically ranges from 90° to 110°. For more immersive VR, it is important to have as wide a field of view as possible. The Lytro Immerge camera has a 120° field of view and is rotated three times to capture a full 360° scene. The Light Field is played back through either a Rift or Vive headset which have a 110° field of view.
At Lytro, the portion of a 360° scene that we capture in one direction using our Lytro Immerge camera rig is called a wedge. A complete captured Light Field usually consists of multiple overlapping wedges. The current configuration of Lytro Immerge has a 120° field of view and is rotated three times to capture the full 360° Light Field.