The Quadraspheric Lens
Why its Best
There are a few styles of Crossview mirrors used in the transportation industry today.
The two most common are the Oval-Elliptical and the Quadraspheric.
|Oval-Elliptical||Elongated Oval Elliptical||Quadraspheric|
The first thing you'll notice when comparing these styles is the quadraspheric design significantly reduces the visual distortion seen in the other styles of convex mirrors. But a potentially worse problem with the oval and round convex lenses (in exterior applications) is that they tend to introduce too much of the sky and frequently with it, glare from the sun. When the sun is low in the sky, this can even happen when an oval mirror is properly rotated all the way down (as in fig.1).
- Fig 1. Oval-Elliptical
- Fig 2. Elongated Oval
- Fig 3. Quadrasphere
The unretouched photos above were all taken in quick succession one morning in the parking lot of the GAPT 2003 convention at Jekyll Island, GA. The snapshots illustrate how a quadraspherical lens resists glare by way of its unique geometric shape. The shadows in these snapshots reveal that they were taken in the same direction and at sunrise.