(This diagram shows an image that's out of focus). A large Sensor makes a shallow depth of field You can use a camera with a large sensor to create a shallow depth of field, but be aware that you ...

The narrow depth of field possible with DSLRs makes it difficult to maintain focus on subjects that are moving relative to the camera, making follow-focus scenes like this classic hard to reproduce.

This lens type is mainly found in DSLR cameras. I use my iPhone as my primary camera for photography, so the ability to control depth-of-field precisely how I want it would be game-changing.