In this video by AbelCine they show you how to control your depth of field when using 35mm sensor cameras.
When you think of a 35mm sensor camera, what characteristics come to mind? Probably the first is shallow depth of field. It is part of what many consider the “look” of that imager size and a principle defining difference between it and other formats. But while some consider this the chief attribute of the format, others may find it to be a detriment in certain situations. For those shooting documentary, run-and-gun productions, a deeper depth of field may be preferable to maintain focus. Fortunately, there is another major facet to the latest crop of 35mm sensor cameras – a very low noise floor. This means that in a camera such as the Canon C300, a wide range of ISO settings can be applied with little objectionable artifacting to the image. Using the concept of the “variable depth of field camera,” you can adjust the available parameters of the camera to yield the depth of field desired for any given image. Watch the video to see this concept demonstrated.