varifocal


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varifocal

1. Optics having a focus that can vary
2. relating to a lens that is graduated to permit any length of vision between near and distant
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
In a varifocal lens, distance vision is controlled by the upper part of the lens, intermediate vision by the middle area and near vision through the lower part of the lens.
I wish I had been able to: Maria has new varifocals that go dark in sunlight, so that she looks like a film star.
Subsequently, the laser beam is adjusted by two lenses that magnify the laser beam that is then reflected from a mirror into the varifocal lens.
It has a metal thermal housing with IP66 protection, 3.5-16 mm varifocal lens with IR-correction and AI, as well as built-in IR LEDs with up to 60 m of working distance.
The series includes surface or flush-mount models with a choice of three different varifocal tenses and offer 15-bit digital video processing.
"The change is so accurate that we can even make the lens bifocal or varifocal, so as well as giving them good vision at distance we can give them good vision for reading.
The DM110 ($995) includes a normal minidome, a 2.8-9.5mm, 3.4x varifocal auto iris lens and more.
Featuring an autoiris varifocal lens in a compact heated dome, the camera position can be adjusted horizontally and vertically.
The 8.5- to 40-millimeter IR varifocal lens features an extended telephoto range while maintaining a maximum aperture of F1.3.