achromatic lens

In 1765, he introduced an astronomical instrument fitted with two achromatic lenses.

Great refractors were large refracting telescopes using achromatic lenses (as opposed to mirrors).

An Achromatic telescope uses an achromatic lens to correct for this.

An achromatic lens is a compound lenses made with two types of glass with different dispersion.

Had he done so, he would almost certainly have invented the achromatic lens.

An early step in the development of the achromatic lens, since it corrects some chromatic aberration.

However, it is well known that he was not the first to make achromatic lenses.

An achromatic lens focused an 8mm-wide, slightly converging light beam.

This was especially true in refracting telescopes, before the invention of achromatic objective lenses.

For an achromatic dispersive lens the converse must be adopted.