F-Stop and DOF

posted to: Camera Lenses

Hi.

There maybe a problem with F-Stop an DOF explanation. In the video (5:54) you say  lower F-Stop numbers mean deeper focus. I think it is the opposite: lower F-stop provides less DOF.

Am I right? Or did I missunderstand something?.

Anyway, thank you for this very useful course.

  • spikeyxxx replied

  • Wayne Dixon replied

    Eek - I hope I didn't get it backwards.   Let me watch it again.

  • Wayne Dixon replied

    Yeah I got the deep and shallow backwards, but I explained it correctly later on haha.

    Fixed.  Thanks Ricardo.

  • Ingmar Franz(duerer) replied

    The F-Stop number is the ratio between the camera's aperture and the camera's focal length:

    Camera Focal Length    divided by    F-Stop    equals    Camera Aperture

    So, increasing the F-Stop number while keeping the focal length constant, means that you divide the focal length by a higher  number and the result is a smaller aperture. A smaller aperture means less light hitting your film strip or camera sensor and blurring your image. Increasing the F-Stop number on a real world camera to the next higher value means reducing the amount of light entering the camera to the half.

  • Ricardo Gerbolés(ricardog) replied

    Yes, it was explained correctly and clearly later.