- Canon EF Mount/Full-Frame Format
- Aperture Range: f/1.8 to f/16
- One LD Element, Two Aspherical Elements
- eBAND and BBAR Coatings
- Fluorine Coating on Front Element
- USD AF Motor, Full-Time Manual Focus
- VC Image Stabilization
- Rounded 9-Blade Diaphragm
- Moisture-Resistant Construction
Outstanding optical quality, even wide open
Even when used wide open at F/1.8 aperture, the lens design provides outstanding image quality with maximum aberration compensation, thanks to optimal use of sophisticated glass materials and highly advanced optical design.
SP 45mm F/1.8 Di VC USD (Model F013) is a 10-element, 8-group construction, utilizing two moulded glass aspherical elements and one LD (Low Dispersion) element.
Two of the aspherical elements effectively correct the field curvature to ensure planarity of the image plane, while efficiently compensating for spherical and comatic aberrations to achieve superb uniformity across the field with high-fidelity point spread reproducibility. Outstanding resolution is rendered from corner to corner and the sagittal comatic flare (a type of aberration that a point image at corners induces a comet tail-like blur), which tends to become prominently noticeable in night scenes, is corrected.
The LD elements and the XLD glass element (SP 35mm) optimally compensate for chromatic aberrations, which tend to become particularly prominent in fast-aperture lenses in general, and deliver crystal clear images without any residual colour fringe.
Fast F/1.8 maximum aperture and integral VC (Vibration Compensation)
The desirable maximum aperture of F/1.8 was chosen as part of the very challenging design goals which included achieving superb optical performance, minimizing the closest shooting distance and integrating VC functionality while packaging those key attributes in a reasonably-sized barrel construction for better practical handling.
Repeated performance simulations were conducted throughout the entire design phase to assure achieving the essential, fundamental property of a fast-aperture lens in full-frame format, namely the harmony between excellent resolving power and beautifully-tuned background blur (bokeh).
The VC feature has become virtually indispensable in the era of high-pixel-density cameras. Freedom in handheld shooting at dusk or in a dimly lit room is dramatically expanded by cancelling the camera shake that often occurs under such low light conditions due to slower shutter speeds. Minute vibrations that plague cameras with high pixel count can also be well controlled to make the most of the sensor’s performance.
Best-in-class MOD (Minimum Object Distance) close-focusing capability
MOD measures 0.29m (11.4”), yielding a magnification ratio of 1:3.4, the best-in-the-class close focusing capability among fast-aperture fixed focal lenses in full-frame format**.
** Rated top among current 45mm and 50mm fixed focal length interchangeable AF lenses for full-frame DSLR cameras excluding macro lenses (as of July 2015; Tamron).
eBAND Coating deployed to thoroughly suppress ghosting and flare
eBAND (Extended Bandwidth & Angular-Dependency) and BBAR (Broad-Band Anti-Reflection) coatings, both providing outstanding anti-reflection effect, are applied to critical element surfaces for maximum light transmission. Internal reflections from element surfaces which cause ghosting and flare are reduced to an absolute minimum. Flawless, crystal clear images can be obtained.
eBAND Coating, a hybrid nano-structured layer with extremely low refractive index coupled with multi-layered anti-reflection coating technology, efficiently minimizes reflection of extremely angulated incident light—something that cannot be achieved by conventional anti-reflection coatings alone.
High-speed AF with USD (Ultrasonic Silent Drive)
Fast, quiet AF is achieved by employing a USD ring-type ultrasonic motor which enables remarkably precise focusing drive with high torque and responsiveness. Because the rotational torque of the USD is generated by waves of ultrasonic vibrations, inherent operating noise is extremely low and practically unnoticeable. In addition, Full-time Manual Focus override is available at any point during the autofocus operation for deliberately shifting focus without switching the AF-MF mode back and forth.
Fluorine coating on the front element repels water and fingerprints
Fluorine coating technology, developed for use in industrial optics applications, has been adapted to photographic lenses. The water and oil repellent coating applied to the front element surface allows instant removal of dirt or smudges with ease. The coating also provides a reasonable level of durability, and will sustain its effectiveness for years.
Seals are located at the lens mount area and other critical locations to prevent infiltration of moisture and/or rain drops and provide moisture-resistant construction. This feature provides an additional layer of protection when shooting outdoors under adverse weather conditions.
Circular aperture for enhanced bokeh
The 9-blade diaphragm retains a nearly circular opening even when stopped down by two stops. Marvellously tuned blur in the subject background can be obtained without generating undesirable shapes of aperture patterns.