Lentar 250mm F/5.6 Mirror
Medium telephoto prime lens • Film era • Discontinued
- Announced:
- · No data
- Production status:
- ● Discontinued
- Country of design:
- · Japan
- Original name:
- · LENTAR 250mm F:5.6
- Class:
- · Slow full-frame medium telephoto prime lens
- · Mirror/Reflex lens
Specification
| Optical design: | |
| 35mm full frame | |
| 250mm | |
| F/5.6 | |
| <No data> | |
| Interchangeable mount (T) | |
| 9.9° (35mm full frame) | |
| Diaphragm mechanism: | |
Diaphragm type: | Fixed |
Aperture control: | None |
| Focusing: | |
| 2.10m | |
| <No data> | |
Focusing modes: | Manual focus only |
Manual focus control: | Focusing ring |
| Physical characteristics: | |
| <No data> | |
| <No data> | |
| Accessories: | |
| <No data> | |
| <No data> | |
| <No data> |
Source of data
- Own research.
From the Photographic Applications in Science, Technology, and Medicine magazine (1969)
Even more compact is a mirror lens made by Meibo in Japan and marketed - primarily for the amateur - in two versions by Hanimex and by Lenco respectively. The Hanimex version has a focal length of 300mm, maximum aperture f/6.3 and comes with a Praktica mount. The Lenco version, known as the 250mm Lentar f/5.6, is similar but has a slightly more powerful glass lens element, thus producing the shorter focal length and larger relative aperture. The Lentar comes with a 4x neutral density filter and a T-adapter mount.
LENS-DB: The Hanimex lens was also, of course, produced with a T mount, and not with a fixed Praktica mount.
Typical characteristics of mirror (reflex) lenses
- Catadioptric system consisting of curved mirrors and optical glass;
- Much shorter, lighter and less expensive designs than conventional super telephoto lenses;
- Outstanding correction of chromatic aberrations;
- Since the aperture is fixed, neutral density filters are used to obtain a smaller aperture;
- Doughnut-shaped out-of-focus highlights.
From the editor
The same lens was sold under the name FOCAL 250mm F:5.6 (isn't it a beautiful name?).
The minimum value on the focusing distance scale was 7 ft. (=2.1m).
The lens came with a 4X=F11 rear mounted filter.
Lenses with similar focal length
| ■Interchangeable mount (1) | |||||||||
| Zoomar Muenchen Reflectar 250mm F/4 | -- | 3 - ? | 2.00m | -- | 1970 ● | ||||
| ■Minolta SR mount (1) | |||||||||
| Minolta RF Rokkor 250mm F/5.6 | -- | 6 - 5 | 2.50m | ⌀62 | 1979 ● | ||||
| ■M42 mount (1) | |||||||||
| TTArtisan 250mm F/5.6 Reflex | -- | 6 - 5 | 2.00m | ⌀67 | 2024 ● | ||||
| ■Nikon F mount (1) | |||||||||
| NiSi 250mm F/5.6 Reflex SLR | -- | 6 - 3 | 2.00m | ⌀62 | 2024 ● | ||||