The 1955 model came with a meniscus lens, later replaced with an achromatic lens. Ramsden received a share in Dollond's patent achromatic lens as dowry. It also featured an achromatic lens with a 10-fold magnification. This lens had the largest aperture of its day for an achromatic lens. An Achromatic telescope uses an achromatic lens to correct for this. The achromatic lens was made Grubb from Chance Brothers glass. An achromatic lens focused an 8mm-wide, slightly converging light beam.