How does one achieve a sharp and clear image? What is depth of field? What is depth of focus? What affects their shallowness? This episode from FilmmakerIQ nicely explains the theory behind using the physics of light. Before starting the lecture you should have some basic understanding of the camera lenses such as the aperture.
This is a part of the Technical Notes series of Nature Documentaries aiming to compile useful technical, theoretical and practical knowledge for documentary filmmakers. The episode builds on material covered in another lecture called The Properties of Camera Lenses.
Through this lecture we get exposed to some quite interesting and esoteric sounding concepts such as “circle of confusion”. It also provides a beautiful demonstration of lens equivalency as well as crop factor by comparing multiple camera systems.
If you want to cultivate yourself further with optical theory you can check out the Khan Academy lecture series on Geometric Optics. MIT’s Open Courseware also provides an online documentary filmmaking course.