iconometer
noun
ico·nom·e·ter
| \ ˌīkəˈnämətə(r)\
Definition of iconometer
1
: an instrument for determining the distance of an object of known size or the size of an object at known distance by measuring the image of it produced by a lens of known focal length
2a
: an instrument that determines the proper objective to be used in taking a picture of given size from a given standpoint and that consists of a diopter and an open rectangular frame sliding on a graduated rod
b
: a direct viewfinder having a metal frame
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