Where is image of the object located? By obtaining the Real image of a distant object at its focus, the focal length of the concave mirror can be estimated as shown in the diagram. The equations are: 1/o + 1/I = 1/f. f: focal length. Incident rays parallel to the optical axis are reflected from the mirror and seem to originate from point \(F\) at focal length \(f\) behind the mirror. A convex spherical mirror also has a focal point, as shown in Figure \(\PageIndex{3}\). In a spherical mirror: The distance between the object and the pole of the mirror is called the object distance(u). F ≈ r/2. Concave Mirror Equation Calculator. The distance between the image and the pole of the mirror is called Image distance(v). It is also known as a mirror formula. For a thick lens (one which has a non-negligible thickness), or an imaging system consisting of several lenses or mirrors (e.g. Online physics calculator that calculates the concave mirror equation from the given values of object distance (do), the image distance (di), and the focal length (f). Focal Length of Concave Mirror Formula. The distance between the object and the convex mirror is measured at the point where the image reflection reaches an approximate size of the object. a photographic lens or a telescope), the focal length is often called the effective focal length (EFL), to distinguish it from other commonly used parameters: . Use this online convex mirror equation calculator to find the focal length… It is an equation relating object distance and image distance with focal length is known as a mirror equation. The distance along the optical axis from the mirror to the focal point is the focal length f of the mirror. Lets see the above shown diagram, Focal Length – The space between the pole P of concave mirror and the focus F is the focal length of concave mirror. Spherical mirror Formula Questions: 1) A lens with focal distance of 30 cm is placed in front of an object, which is located at 1 m from it. If a concave mirror with a focal length of 10.0 cm creates a real image 30.0 cm away on its... Why are concave mirrors used in headlights? r: Curvature radius. The image on a convex mirror is always virtual, diminished and upright. Where: o: Object distance. The radius of curvature is negative, so the focal length (f) is also negative. Focal length ≈ curvature radius / 2. I: Formed image distance.