Soaring creative ideals and advances in camera performance demand a new approach to lens technology. With a clear vision of the cameras' future, Sony has redefined the lens.
An essential ingredient of astonishing resolution is a new XA (extreme aspherical) lens element with better that 0.01-micron surface precision. Refined simulation software has also made a vital contribution, making it possible to predict and eliminate potential problems throughout the design and manufacturing processes and thereby realize the highest design standards without compromise. Lens coatings can be included in the simulation, allowing designers to accurately predict how they will affect ghosting and color in the final product. That in turn has made it possible to use Sony's Nano AR Coating technology in the most effective way. Industry-leading actuator technology inherited from professional Sony movie equipment contributes too, providing the focusing precision needed to fully realize each lens's resolution potential.
In general, if an aperture uses 7 or 9 aperture blades, then the shape of the aperture becomes a 7-sided or 9-sided polygon as the aperture is made smaller. However, this has a certain undesirable effect in that the defocusing of point light sources appears polygonal and not circular. lenses overcome this problem through a unique design that keeps the aperture almost perfectly circular from its wide-open setting to then it it closed by 2 stops. Smoother, more natural defocusing can be obtained as a result.
Spherical aberration occurs in conventional lenses due to misalignment on the focal plane between light coming from the periphery of the lens and light coming from the center of the lens. Despite the development of various methods to correct this aberration, the flaw remains apparent particularly in wide-angle lenses with large apertures. Unless, that is, the lens includes specially developed aspherical lens elements. This advanced optical technology minimizes spherical aberration in all types of lenses, including large-aperture lenses. Aspherical lenses maintain high contrast in images taken with the aperture wide open, and effectively suppress image distortion. Also, because fewer lens elements are required, the entire lens stays compact.
Sony AA (advanced aspherical) lens molding technology takes this to the next level, making it possible to create even thinner, lighter aspherical elements. Enormous technical hurdles have been overcome in achieving the required surface precision, with the resulting AA elements providing precise, tight light control that enables a reduction in the total number of elements required as well as the overall size of the lens, while achieving extremely high imaging performance. A more compact optical path also contributes to faster, more responsive focus operation.
As focal lengths get longer, lenses built with conventional optical glass have difficulties with chromatic aberration, and as a result images suffer from lower contrast, lower color quality, and lower resolution. To counter such problems, ED glass was developed and is included in select lenses. It dramatically improves chromatic aberration at telephoto ranges, and provides superior contrast across the entire image, even at large aperture settings. Super ED glass provides enhanced compensation for chromatic aberration.
Original Sony Nano AR Coating technology produces a lens coating that features a precisely defined regular nano-structure that allows accurate light transmission while effectively suppressing reflections that can cause flare and ghosting. The reflection suppression characteristics of the Nano AR Coating are superior to conventional anti-reflective coatings, including coatings that use an irregular nano-structure, providing a notable improvement in clarity, contrast, and overall image quality.
SSM is a piezoelectric motor that contributes to smooth and silent AF operation. The motor produces high torque at slow rotation, and provides immediate start and stop responses. It is also extremely quiet, which helps keep autofocusing silent. Lenses that feature SSM also include a position-sensitive detector to directly detect the amount of lens rotation, a factor that improves AF precision overall.
SSM consists of a rotor (left), and a stator (right) on which piezoelectric elements are mounted.
A new direct-drive version of Sony’s SSM system is used for precision positioning of the heavy focus groups required for the full-frame format, allowing precision focusing even within the lens’s shallowest depth of field. The DDSSM drive system is also remarkably quiet, making it ideal for shooting movies where focus is constantly changing during recording.
Sony mount lenses with power zoom offer enhanced control and expression for moviemaking, with smooth, consistent zooming that is difficult to achieve manually. Acceleration and deceleration are smooth too, and tracking is excellent throughout. All of this is made possible by a blend of mature camcorder technology with stateof- the-art innovation, from optical and mechanical design to original actuator technology that all comes together through exacting in-house manufacturing.
Gyro sensors built into the lens detect even the slightest movement, and the stabilization lens is precisely shifted to counteract any image blur that might occur. The use of precision, quiet linear motors and technology inherited from high-end Sony professional camcorders results in exceptionally quiet, effective image stabilization that contributes to high-quality movies as well as stills.
Moving around while shooting movies means more camera shake that can cause blur. Although conventional image stabilization systems were not effective at compensating for this type of movement, “Active Mode” employs a wider range of motion for the compensation lens, achieving improved stabilization over a greater range of camera movement. Stabilization at the wide end of the zoom range is significantly improved, facilitating handheld movie shooting with minimum image blur.
SMO (Smooth Motion Optics) is a new Sony optical design concept for interchangeable lenses that is specifically aimed at achieving the highest possible image quality and resolution for motion images. SMO design addresses three main issues that are critical for moviemaking:
- Focus breathing (angle of view instability while focusing) is effectively minimised by a precision internal focus mechanism.
- Small focus shifts that can occur while zooming are eliminated by a special tracking adjustment mechanism.
- Lateral movement of the optical axis while zooming is eliminated by an internal zoom mechanism that keeps the length of the lens constant at all focal lengths.
The level of precision required demands both exacting design and constant monitoring during manufacture, but the benefits for moviemaking with large aperture lenses, particularly on large format sensors, are spectacular and well worth the effort.
* Currently available on SELP28135G only.
Submit up to 5 photos shot with any of Sony’s G Lens and stand a chance to win the 85mm F1.4 G Master lens (SEL85F14GM). Contest Ends 19th August, 2016.
Having an eye for Greatness demands nothing but the very best. That’s why we’ve assembled a panel primarily consisting of Sony's professional photographers to lend their experience, talent and discerning eye. Entries will be judged together with Sony representative.
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