The most difficult lens riddlesOptics quiz
What kind of lens was most likely used for this photo?
fixed focal length
Such shallow depth-of-field is possible with lens of large aperture size (small f-number). The large aperture is a typical feature (and advantage) of a fixed focal length lens. The photo was taken with a 50mm f/1.4 lens.
Which of the following camera lenses is typically more expensive?
The smaller the f-number, the larger relative aperture there is, and that means more light for the exposure. Each aperture has half the light gathering area of the previous one.
What kind of photos can be made with standard zoom lens mounted in the reversed position?
Macro photography may be accomplished by mounting a lens in reverse, in front of a normally mounted lens of greater focal length. This method allows most cameras to maintain the full function of electronic and mechanical communication with the normally mounted lens, for features such as open-aperture metering.
What kind of camera lens is that?
Small front lens elements are typical for macro lenses.