Specification

Attention

▶These focusing lenses are made for use to image an object located in an infinitive distance or using a point of source as a parallel light. Near distance of an image will not produce any good optical result.

▶The correct direction to input a parallel light is on the top side of the SIGMA KOKI letters. If the direction is wrong, the spherical aberration　will be big and the image unfocused.

▶If the wavelength is applied in-correctly, the spherical aberration and transmission will be bad.

▶Usage with high power laser or near　high temperature light source, the high heat build-up in the lens may alter the focal length. To avoid　this, heat prevention is required.

▶To reduce the focus spot size, ensure that the input beam diameter (1/e2) is reduced to half of the effective diameter of the focus lens.

▶These focusing lenses are not chromatic lenses;　 they are not optically corrected.

▶The lenses have 3% to 4% of reflectivity; therefore about over 13% of loss is expected in transmission.