How to choose eyepieces
How to Choose Fieldscopes
Magnification is determined by the combination of Fieldscope body and eyepiece.
Eyepieces are available in various types including a wide type that has a fixed magnification, and a zoom type with non-step adjustable magnification.
Magnification of Fieldscopes
The magnification of a Fieldscope is determined by the combination of the body's effective diameter of the objective lens and the eyepiece. Eyepieces are available in various types including a wide type or a zoom type, and eyepieces for digiscoping have also been developed. Choose the appropriate magnification according to your needs.
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| Wide type: fixed magnification (low magnification) | Wide type: fixed magnification (high magnification) | Zoom type | |
|---|---|---|---|
| Characteristics |
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|
|
| Effective diameter of the objective lens/Magnification | 85mm/20x 65mm/16x |
85mm/75x 65mm/60x |
85mm/20-60x 65mm/16-48x |
| Field of view* |
|
|
|
- *When using 85mm effective diameter of the objective lens
- *Photos are simulated viewfinder images.
Comparing zoom type eyepiece and fixed magnification eyepiece
A Nikon's zoom type eyepiece allows you to adjust the magnification at any position from low to high and lets you enjoy various magnifications. Compared with a fixed-magnification eyepiece, the field of view of a zoom type eyepiece is narrower, however, if you plan to use a Fieldscope in a variety of situations, it is recommended for your first eyepiece. A fixed-magnification eyepiece is designed to secure a wider field of view. You can choose the most appropriate magnification eyepiece according to your particular needs, and you will obtain high-quality images whichever strength you select, because the optical structure is optimized for each magnification.
If your observation conditions are fixed and require a wider field of view, or for digiscoping where vignetting must be minimized, fixed-magnification eyepieces are recommended.
The field of view comparison between a zoom type eyepiece and a fixed-magnification type eyepiece.
A zoom type eyepiece can be set at several magnification positions within the zoom range.
Compared with a fixed-magnification type at the same magnification, the field of view of the fixed-magnification type eyepiece will be wider.
(Field of view at 1,000m is 58m)
(Field of view at 1,000m is 38m)
- *When using 85mm effective diameter of the objective lens
- *Photos are simulated viewfinder images.