Semitecolo, Leonardo, 1750 c.50
Adler Planetarium and Astronomy Museum Arrow right Arrow left
Photo

ronchigram
Basic Info

Maker: Semitecolo, Leonardo

Year: 1750 c.50

Year Range: -

Year Notes:

Manufacturing Location: Italy

Signature: LEONARDO SEMITECOLO

Signature Notes:

Inscriptions:

No stand present.

Collection: Adler Planetarium and Astronomy Museum

Accession #: W-180

Sources:

Project investigation

Public Notes:

Main tube is covered in orange-red vellum. Gold-tooling on one end is mirrored at other end. Angels are incorporated in the twining floral pattern. Tooling may have first been in silver. Maker's name is stamped among the second section of tooling. Horn ferrules at both ends of main tube. Objective glass has horn mount. Horn eyepiece mount has apparatus for a screw-in end cap (missing). Three draw tubes, covered in green vellum with horn ferrules and wooden stops. Single extension rings on first two draws, double on third. Three-lens erector tube of white pasteboard splashed with red. Soft (or beech) wood lens mounts.

Length (open): 640 mm

Length (closed): 248 mm by 54 mm diameter

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style spyglass

Functional style

Materials: horn, pasteboard, vellum, wood, glass, gold tooling

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 2.38 ± 0.005 -2.37 ± 0.007 2.55 ± 0.001 392.60 ± 0.1 1.54 ± 0.0001 58.00 ± 1
Complete

Eyepieces

Notes:

Eyepiece 1
fD focal length (mm): free aperture (mm): full aperture (mm): s spacing (mm): CA curvature (diopters): CB curvature (diopters): M magnification: FOV field of view (degrees): Thickness:
Lens 1 40.90
Lens 2 40.20
Lens 3 40.80
Eyepiece 2
fD focal length (mm): free aperture (mm): full aperture (mm): s spacing (mm): CA curvature (diopters): CB curvature (diopters): M magnification: FOV field of view (degrees): Thickness:
Lens 1 40.20
Eyepiece 3
fD focal length (mm): free aperture (mm): full aperture (mm): s spacing (mm): CA curvature (diopters): CB curvature (diopters): M magnification: FOV field of view (degrees): Thickness:
Lens 1 40.80