Technologies such as HD and 3D are reshaping how we record, produce and distribute programming. Viewers are becoming more savvy with each passing day and now expect crisp, lifelike images to jump out from their home theater systems and movie screens. These demands have necessitated advancements in lens technology that are helping professionals capture the sharpest images possible and deliver those robust pictures viewers now insist on.
In part one of our five-part series on lens technology, I’d like to review advances made on digital cinema lenses. For years, died in the wool cinematographers steadfastly held on to their 35 mm film over digital video. Recent lens and camera developments, however, are giving these experienced professionals compelling reasons to think about converting.
Today’s digital cinema lenses can replicate much of their film counterparts. How? By using new designs and technologies. For example, the diagonal image size of a CCD in a traditional HD camera is 11 mm. A 35 mm film format lens has a diagonal image size of 27.26 mm. New digital lenses are now available that have the same angular field of view as the most commonly used 35 film format lenses, so cinematographers can easily adapt to the HD format.
Cinematographers also demand minimal changes in field of view during focusing. Traditional digital lenses suffer from a phenomenon called focus breathing in which there are slight changes to the field of view during focusing. Inner focus and floating methods has been developed that reduce focus breathing to a level so low it does not interfere with the visual content of the production.
That’s only a part of the story, though. Cinematographers also demand more precise, aberration-free images. To meet this demand, lenses now incorporate a low dispersion and high refractive index glass, such as calcium fluoride or fluorite, to reduce chromatic aberrations.
Plus, each glass material is coated by a special EBC coating that decreases flair and ghosts. It also provides for a high contrast, flat field, razor sharp corners and a high MTF image with low-color fringing throughout the image plane.
In cinematography, lenses are chosen for each scene according focal length. This makes it extremely important for all lenses to have the same color-balance. Advanced design and manufacturing processes are now being employed so lenses exhibit the same transmission characteristics.
To learn more about lens technology and how it is helping reshape digital cinema, visit Fujinon.com.