The roof or Amici prism deviates or deflects the image through an angle of 90
degrees. It is a right-angle prism whose hypotenuse has been replaced by a
90-degree TIR roof. Glass that does not contribute to the clear aperture has
been trimmed away to reduce
size and weight.
- Roof prisms are suitable for applications that demand both right-angle
deflection and image erection (a combination left-to-right angle deflection
and top-to-bottom inversion, equivalent to a 180 degree rotation about the
- These are normally uncoated for use in TIR mode.
- Protected aluminum or internal silver coatings may be specified for roof
surfaces when used in wide field applications beyond TIR limits.
- Antireflection coated entrance and exit faces are also available.
|+/-5 arc seconds
|+/-30 arc seconds