Welcome to part three of our series on lens technology and its influence on today’s broadcast and video world. Today, let’s take a close look at optical stability technology.
High def has brought with it crystal clear pictures that allow viewers to see the smallest imperfections. It also has made slight variations in camera operation stand out much larger than if they were made in standard definition.
That is one of the reasons optical stabilization technology has become so important. First, let’s explain how and why a shaky picture happens. To create an image, light rays travel through the lens into the camera, where they are converted into an image. If the camera operator happens to be on an unstable platform, is shooting in a driving wind, or simply has an unsteady hand for a fraction of a second, the lens will move. This causes the light rays to bend, relative to the optical axis. The result is a blurred image.
Optical stability technology has been developed to make sure those images remain crystal clear. Lenses are designed with OS systems that feature gyro-sensors that can detect the slightest movement that may cause vibration and subsequent bending of the light ray. The sensors detect the angle and speed of movement and send this data to a high-speed 32-bit microcomputer. The microcomputer then converts the detection signals into a correction signal that is applied to the optical correction system which actually moves the internal lens elements. This offsets the movement and helps to maintain a stable image.
OS systems are not just helpful during HD shoots. They’re also handy in applications in which a very long focal length is necessary, since the slightest movement will cause image shake and an unacceptable picture.
To learn more about how lens technology is reshaping optical stabilization systems, visit Fujinon.com.
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.
Often times, we can be blinded by specifications when evaluating which lens will be best for our particular shooting requirements. To get a clear picture of the right lens for your needs, there are numerous other variables to pay attention to that rarely are included on comparative spec sheets.
For example, coatings and barrel construction have a tremendous effect on the richness of your final video. Coatings are especially important when evaluating how a lens will operate in various atmospheric conditions, such as temperature, moisture and sun exposure.
A high-end lens coating will reduce glare and reflectance. The better reflectance a lens has, the truer and richer colors the lens is able to produce, especially at the darker spectrum. Additionally, lenses with lower contrast can’t hold black or dark color shades as well as those with high contrast. For these reasons, properly coated lenses will transmit a noticeably higher percentage of an image than an uncoated lens. This will result in a higher quality image reaching the camera’s sensors, and ultimately better footage.
Fujinon recognizes the importance of lens coatings and has developed a manufacturing process that includes a BC coating to reduce ghost and flare, while increasing light transmission. Additionally, a proprietary anti-fogging design is used to minimize lens fogging and downtime due to moisture when conditions change.
To learn more about the importance of coatings and other variables when selecting a lens, visit www.fujinon.com