| Prescription of 280 mm CA F/4.2 - F/20.24 Maksutov telescope | ||
| Symbol | Definition | mm or F/ratio |
| CA | Clear Aperture of corrector lens Hayward BSC2 Cat# 517645 | 279.40 |
| BA | Back Aperture of corrector lens Hayward BSC2 Cat# 517645 | 285.75 |
| Tc | Thickness of corrector lens | 29.34 |
| Dm | Diameter of primary mirror | 304.80 |
| Tm | Thickness of primary mirror | 50.80 |
| Dh | Diameter of central hole in primary | 50.80 |
| Ds | Diameter of secondary mirror | 73.15 |
| R1 | Radius of curvature of 1st lens surface | -434.19 |
| R2 | Radius of curvature of 2nd lens surface | -450.77 |
| R3 | Radius of curvature of primary mirror | -2,400.94 |
| R4 | Radius of curvature of secondary mirror (Cassegrain focus) | -640.89 |
| F | Distance from primary mirror to prime focus | 1,224.94 |
| S | Separation of corrector lens and primary mirror | 1,275.89 |
| SD | Separation between prime focus and Cass secondary surface | 254.00 |
| BD | Distance from primary mirror surface to Cassegrain focus | 254.00 |
| BFL | Back Focal Length | 1,224.94 |
| EFL_prim | Effective Focal Length (prime focus/Newtonian) | 1,173.48 |
| EF/ratio_prim | Effective F/ratio (prime focus/Newtonian) | 4.20 |
| EFL_cass | Effective Focal Length (Cassegrain) | 5,654.04 |
| EF/ratio_cass | Effective F/ratio (Cassegrain) | 20.24 |
| Corrector meniscus: Hayward Scientific BSC2: nD 1.517645; vD 64.5 | ||
| nC (red) 1.51462; nF (blue) 1.52264 | ||
| Glass type deduced from Mak Club circular No. 60 RI values | ||
| used for ray tracing studies | ||
