two dimension-three dimension phenomenon

two di·men·sion-three di·men·sion phe·nom·e·non

(tū' dī-men'shŭn-thrē'di-men'shŭn fĕ-nom'ĕ-non)
An experience in telescopic endoscopy in which a two-dimensional image appears to be three-dimensional because of the movement of the endoscope in and out of the view of the object.