Huygens, Christiaan, 1655
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photo - objective
Basic Info

Maker: Huygens, Christiaan

Year: 1655

Year Range: -

Year Notes:

Manufacturing Location: the Netherlands


Signature Notes:


No stand present.

Collection: Utrecht University Museum

Accession #: LI-38


The Huygens Collection catalogue, Museum Boerhaave (Leiden, 1995): table IV. Louwman Collection of Historic Telescopes catalogue, p. 40.

Public Notes:

Grayish glass. Objective lens with which Christiaan Huygens discovered Saturn’s moon Titan. On the rim of the lens are engraved the focal length “X [pedes]”, the date when the lens was finished “3 FEBR. MDCLV”, and the first part of the anagram, “Admovere oculis distantia sidera nostris”. Plano-convex lens Ø 5,7 cm. Focal length measured as 336,7 cm. Radius of curvature, front: 176 cm; ibidem back: flat. Maximum thickness 0,34 cm.

Length (open): NA

Length (closed): NA


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style

Functional style

Materials: glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

CA curvature (diopters): CB curvature (diopters): PD lens power (diopters): fD focal length (mm): t thickness (mm): free aperture (mm): full aperture (mm): nD refractive index: ν Abbe No.:
Lens 1 1760.00 3367.00 3.40 57.00 1.52