In this week’s studio we learned more about focal length and depth of field to strengthen our comprehension on cinematography and to have a better grasp on using a Sony EX3.
FOCAL LENGTH
wide field of view – short focal length/ 5.9mm (FISH EYE)
standard focal length (25mm EX3)
narrow field of view – long focal length/ 81.2mm (Telephotos)
DEPTH OF FIELD – the part of the picture that’s in focus
short focal length – great/substantial depth of field – everything’s in focus – wide lens – deep focus – exaggerate speed and movement – f16 narrow aperture
long length – shallow depth of field – narrow depth of field – camera movements magnified – f2 wide aperture
In order to put our understanding into practice, we did an exercise on determining the depth of field using three factors – focal length, aperture and point of focus. The task was to film two portraits with one of them having the shallowest depth of field that could be manipulated to and the other was the greatest depth of field.
For the first clip we tried to achieve the shallowest depth of field we can in the environment that we chose, which is very low in lighting, the main source would be from outside the windows. So to get the correct exposure, the aperture could only be set to as wide as f5.6. And for focal length, first we set it to 81.2mm, which is the longest focal length on Sony EX3. We pulled the camera further from the subject to the far end of the room, but the shot is still too tight. So we shortened the focal length to 55mm to pull it back to a medium close up.
We tried to achieve the greatest depth of field by adjusting the focal length to the other end of the ring, setting it at 5.8mm, and because of the long focal length, I had to move the camera really close to the subject, around 1.5m. Because of the general low lighting environment, the smallest aperture that could be set to while maintaining a proper exposure was f7.
The exercise really helped with familiarizing us with the lens and the technical aspect of how a camera works.