LENSES

5001 Objective lens, 120mm diameter, 1500mm (also available as 1300mm) focal length.

This is the lens intended for the construction of top-quality astronomical refractors. We use it in our top-of-the-range refractors. It is a research grade lens and we commend it to you.

Diameter of lens 4.842” (123mm)
Focal length of lens 59” (1500mm) ALSO 51" (1300mm)
Type of lens Air-spaced achromatic doublet, fully anti-reflection coated. SUPERB!

£510.00

5003 Objective lens, 60mm diameter, 15 3/4" focal length

This is a military specification achromatic doublet, anti-reflection coated on front and rear surfaces.
Focal length 400mm 15 3/4"
Diameter 60mm 2.360"
Edge thickness 13mm 1/2"

£80.00

5004 Objective lens, 60mm diameter, 22 1/8" focal length

This is another military achromatic doublet, coated on the front surface.
Focal length 560mm 22 1/8"
Diameter 60mm 2.360"
Edge thickness 13mm 1/2 "

£60.00

Achromatic Singlet and Doublet lenses

The following lenses are all achromatic doublets (except for the three that are specifically mentioned as being singlets). The shorter focal length lenses can all be used to make Plossl eyepieces, while the longer focal length lenses can all be used as telescope objective lenses.

The catalogue number is followed by the diameter of the lens, in mm and the approximate focal length is given in millimeters and inches.

Those lenses whose catalogue number begins with 9 are in a metal cell, while those whose catalogue number begins with 5 are brand new. All other lenses are second hand, usually of military origin, and are generally in excellent condition. Since they have been used, they may have small blemishes.