視差法(光學凸球面鏡問題)

According to the principle of [no parallex](視差法), there will not be any apparent displacement of two objects when viewing from different angles if and only if the two objects are physically coincident.

Although the image formed by a convex mirror is virtual, it does [exist] at a distanceas behind the mirror. As long as it is located, e.g. using a search pin, the principle of no parallex applies irrespective it is a virtual or real image. Under such situation, the search pin and the virtual image do coincide with each other and thus no parallex occurs.