Categories By Element
Categories By Function
Positive focus length. Most suitable where one conjugate is more than five times the other, e.g. in sensor application or for use with near collimated light.
Most suitable where the conjugates are on opposite sides of the lenses and the ratio of the distances is less than 5:1, e.g. as simple image relay components.
Negative lens with the form most suitable where one conjugates is more than five times the other, e.g. producing divergent light from a collimated input beam.
Negative lens with the form most suited to producing diverging light or a virtual image, where the input light is converging.
These lenses may be used to increase the numerical aperture of a positive lens assembly, without an undue increase in the aberrations.