In this chapter we will take a look at a particular aspect of the design criteria for the new Canon cine zoom lenses. Because these lenses were born squarely within the new era of digital cinematography the goal of endowing them with full 4 k optical performance made sense for two reasons: one, such high resolution would significantly benefit high-end 2 k /HD digital cine cameras, and second, it would anticipate the now escalating emergence of 4 k digital cine cameras.
If the batteries do fail, the EF can still be used manually from 1/2 - 1/ 1000 sec. The Variable Aperture AE control will not operate, but you can manually adjust the aperture ring of the lens. A basic exposure guide to follow for bright sunlight (with distinct shadows) is to make a fraction representing the shutter speed needed at f/16 by putting a "one" over the film's ASA rating.
