Carl Zeiss India [Bangalore] Ltd. Manufactures Optical Performance Lenses for Positive Lock Mount. Carl Zeiss India [Bangalore] Ltd. Manufactures largest MMZ G coordinate measuring machine. Optical Performance Lenses for Positive Lock Mount are both fast surpassing that of all standard speed primes. Optical Performance Lenses for Positive Lock Mount open up new creative opportunities of film making. A widest stop of T1.3 allows shooting in low or available light for more natural-looking shots and a reduction of the lighting budget. In addition, a wide open stop creates the cinematic look of an extremely shallow depth of field.