Or a triplet may be designed with three spaced glasses, e.g. the Cooke triplet.
Lens | Lens, Pas-de-Calais | Independent Lens | Nicholas Lens | lens | Fresnel lens | Single-lens reflex camera | Panasonic Lumix 45mm lens | Cooke triplet | Panasonic Lumix G 14mm lens | Panasonic Lumix 20mm lens | Panasonic Leica DG 25mm lens | M42 lens mount | Lens (optics) | Judith of Lens | Digital single-lens reflex camera | Ultra wide angle lens | Through-the-lens metering | Mirrorless interchangeable-lens camera | Lens (Pas-de-Calais) | lens (anatomy) | Lambert II, Count of Lens | Bernard Lens | Achromatic lens | Zoom lens | zoom lens | Telephoto lens | single-lens reflex camera | Sidney Lens | Panasonic Lumix G X Vario PZ 45-175mm lens |