| Radius of curvature | 21311.6 mm concave | 
| Conic constant | -1.09763 | 
| Mirror diameter | 4022.9 mm (see CH2150.260-A001) | 
| Bare mirror clear aperture | diam 3965.4 mm | 
| Central hole | diam 1317.8 mm | 
| Used clear aperture | diam 3934 mm (August 00 after installation of seal CH2922-A001) | 
| Central obscuration | diam 1651 mm (PF cage baffle for f/8 M2) | 
| Light-collecting area | 10.014 m^2 | 
| Distance from primary | 7494.25 mm | 
| Radius of curvature | 9569.6 mm convex | 
| Conic constant | -5.2625 | 
| Clear aperture | diam 1295.4 mm | 
| Distance from primary | 8.6212e03 mm | 
| Radius of curvature | 4.9865e03 convex | 
| Conic constant | -3.044206 | 
| Clear aperture | 
| Distance from primary | 9.6871e03 mm | 
| Radius of curvature | 2.1153e03 convex | 
| Conic constant | -2.8056 | 
| Clear aperture: |