- High-quality optics- 1/3-inch and 1/2-inch formats- Reliable, robust construction- Focal length options- Compact designFor optimizing angular fields right on site, varifocal lenses are the most versatile and practical solution available. These lenses allow for setting virtually any angle of field, which maximizes surveillance effects. Installers do not need to carry several different focal length lenses – and installation is more efficient because they can find the right angles of field without moving the camera set-up. If the field-of-view requirements change after installation, modification is simple by just altering the lens’ focal length settings.