Viewfinders, used in automobiles to locate the position of the vehicles behind, are made of

Viewfinders or rear-view mirrors in automobiles are made of convex mirrors. These mirrors are preferred because they always produce an erect (upright) and diminished image of the objects behind the vehicle [3]. A key advantage of convex mirrors is their wider field of view compared to plane or concave mirrors, as they are curved outwards [1]. This allows the driver to monitor a much larger area of traffic, facilitating safer driving [1]. While plane mirrors produce images of the same size as the object, they offer a limited field of view [1]. Concave mirrors are generally avoided for this purpose because they can produce inverted images depending on the object's distance [2]. Therefore, the convex mirror's ability to provide a comprehensive, upright, though smaller, view of the surroundings makes it the standard choice for automotive viewfinders.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Uses of convex mirrors > p. 142
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Activity 9.5 > p. 141
3. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 10: Light: Mirrors and Lenses > Activity 10.3: Let us explore > p. 156