OTA · 1992–2011
Takahashi FS-128
Key specifications
| Aperture | 128 mm |
|---|---|
| Focal length | 1040 mm |
| Focal ratio | f/8 |
| Optical design | Fluorite Doublet |
About
128 mm f/8 air-spaced fluorite doublet apochromat (Fraunhofer, front fluorite), ~1040 mm focal length. The 5-inch member of the FS fluorite family, sharing its lens design and cell with the smaller and larger siblings.