(3) These are all negative design eyepieces and therefore slightly undercorrected chromatically. They are ideal for use with high powered apochromatic objectives and good for general purpose use with fluorites and achromats.
(7) Huyghens type eyepieces consist of two plano convex lenses mounted with their convex side toward the object. This is a negative design with the stop between the lenses. This series accepts 21mm diameter reticles. Field of view is approximately 30°. They are ideally suited for use with lower power achromatic objectives. Like all ROLYN eyepieces they are 23mm diameter to fit all standard tubes.
The ROLYN Micrometer Eyepiece, sometimes known as a Filar Eyepiece, has a Kellnar type ocular of 10 magnification with adjustable focusing. The reticle is 10mm long with every mm numbered. One revolution of the micrometer corresponds to one division indicated on the reticle. The reticle has 10 divisions. The micrometer has 50 divisions. One full turn equals one reticle division.
This Filar eyepiece is similar to the 10X Micrometer Eyepiece except it is 15 power. The reticle has 8 divisions. The micrometer dial has 100 divisions. One full turn equals one reticle division.
The Ramsden eyepiece like the Huyghens has two plano convex lenses but they are positioned with the convex side facing each other. This yields a positive design with the stop below both lenses. It has a superior field of view of about 50° and slightly less distortion.
A simple one piece ocular that gives 10 to 20 magnification by turning a dial. It is a periplanitic design with a field of view of 10.2mm at 10X, 9.2mm at 12X, 8.4mm at 15X and 7.7mm at 20X. It will not accept reticles.
Rolyn Optics Co. • 706 Arrowgrand Circle •
Covina, CA 91722
