When I was younger, I remember hearing the phrase “a 50 is a 50 is a 50”. A phrase coined by Denny Clairmont and carried on by my father. This was in regards to people using 35mm format lenses on a 16mm format camera. Denny or my father would scold people for saying that a particular focal length is multiplied when used on a smaller format. This is simply inaccurate. Unfortunately this mistake has become even more common today with popular formats such as Super 35 or APS-C. These are considered “crop sensors” when compared to 35mm Full Frame and only utilize a portion of the intended image circle created by a Full Frame lens. The only thing that changes when using a 35mm FF lens on a Super35/APS-C sensor is the field of view (FOV) or the angle of view. So unless you’ve spent the past 30 years memorizing the field of view associated with a specific focal length, strictly on 35mm Full Frame, don’t bother trying to compensate for crop factor.
A connoisseur of fine motion picture lenses, Matthew has spent over half his life servicing, refining, selling, manufacturing, and collecting cinema lenses from around the world. Chief Operating Officer of Duclos Lenses and Founder of TheCineLens.com, Matthew has been contributing to the motion picture industry for over 15 years, and to this site for over 5 years. View all posts by Matthew Duclos