Q.State the restrictions for having images produced by spherical mirrors to be appreciably clear.

[!TLDR] Clear spherical-mirror images require small aperture, paraxial rays close to the axis, and a beam confined to a narrow cone around the axis -- conditions under which spherical aberration stays negligible. [!ANSWER] Small aperture mirror; o …

The mirror formula 1/f=1/v+1/u and the relation f=R/2 both rest on the PARAXIAL approximation, and are only appreciably accurate under three related restrictions: (i) the mirror's aperture (diameter) must be small compared with u, v and f -- conventionally at least ten times smaller;

(ii) objects and images must be situated close to the principal axis, not far off to one side; …

State the three linked paraxial-ray restrictions (small aperture, near-axis object/image, narrow-angle ray cone) that …

Giving only a vague answer like 'the mirror must be small' without specifying the precise paraxial conditions (near-axis positio …