LEICA DG Lens Story - The Quest for Changing Photography
LEICA DG NOCTICRON 42.5mm / F1.2 ASPH. / POWER O.I.S.
1. Development background
The history of medium telephoto lenses
The medium telephoto category covers lenses in the 80mm to 100mm range. Over the years, starting with the venerable Leica Thambar 90mm F2.2, a number of lenses have been introduced offering bokeh control. Large-aperture high-performance 85mm lenses for portrait photography have long been an essential tool for professional photographers, and lenses of this type are available with the latest optical design technology, superior coatings and advanced device technology. The outstanding capabilities of the best of these lenses have been proven by their longevity in the market. The Nocticron 42.5mm F1.2 is a large-aperture medium-telephoto lens developed to give you the superb feel, quality, and performance characteristic of a Leica DG lens.
The Leica 50mm Noctilux (F0.95) is considered one of the world’s brightest lenses. The new 42.5mm lens developed by LUMIX for the Micro Four Thirds format provides the same class of optical performance.
Leica reserves the “Nocti” prefix for its finest lenses, and this new 42.5mm lens justifiably deserves the name Nocticron. For 35mm format photography, the Noctilux is peerless. And in the digital realm of Micro Four Thirds, the Nocticron reigns supreme.
1/320 sec, F1.2, ISO 200
© Daniel Berehulak
2. Development aims
1. Focal length and large aperture (low F number)
The Nocticron was designed with the primary emphasis on portrait photography. Free of perspective distortion and without noticeable visual compression, the medium-telephoto focal length of 42.5mm provides flattering perspective and naturalistic background blurring pleasing to the eye. The larger the F number, the shallower the depth of field and the greater the scope for expressively isolating an in-focus subject from a blurry background, so a large F1.2 was chosen for the lens aperture specification.
Because facial expressions change from moment to moment, portrait shooting is a difficult skill to master. For this reason, intuitive operation is an essential attribute of the Nocticron lens. That is why the AF/MF switch and diaphragm control ring are readily accessible on the barrel. Along with ease of use, you enjoy the comfortable feel of premium-quality metal materials.
3. Image quality goals
When shooting a portrait you want to artfully capture an image of the subject. Normally you want the face the stand out in a natural transition against a beautiful foreground and background bokeh. So, while aiming to sharply focus on the eyes, for example, you also want to have smoothly graduated bokeh moving towards the subject’s nose and hair. This lens was developed under Leica DG’s strict quality standards to deliver pin-sharp resolution along with gentle, natural bokeh to allow outstanding creative freedom.
Optical engineering
Handling is easier with an internal focus system, which keeps the weight of the moving lens elements in better balance. In 11 groups comprising 14 elements, the internal configuration includes advanced optical components such as large diameter aspherical lenses, ED lenses, and UHR lenses.
1/250 sec, F1.2, ISO 400
© Mitchell Kanashkevich
4. Specification goals
4.1. Optimisation for overall optical solution
The top lens is designed to capture as much light as possible. To minimise the effects of spherical aberration and optimise the overall optical solution, this top element is a UHR (ultra-high refractive index) lens. At the same time, peripheral aberration towards the edge of the field is also minimised. UHR lenses are prone to chromatic aberration, which is successfully corrected by incorporating an innovative doublet element.
4.2. Delicately balanced blurring for tasteful bokeh
Although aspherical lenses are seldom used for telephoto and medium telephoto optics, this lens includes two such elements. They function to make the out-of-focus blurring look more gradual and more beautiful. They also make in-focus spherical aberration effects almost imperceptible. The result is superb imaging performance along with tasteful bokeh. Even while maintaining in-focus resolution, behind and in front of the depth of field the aberration is adjusted to achieve a pleasing gradual transition. Meanwhile, at the front and rear, blurring is delicately balanced.
4.3. Meniscus-type ED to further boost lens performance
Use of a meniscus-type ED element, curved on both sides, boosts lens performance by suppressing ordinary chromatic aberration and effectively reducing edge-of-frame curvature and flare.
4.4. Dual Image Stabiliser - Dual I.S.2
Superb imaging performance is not solely determined by optics. Optical rendering is greatly enhanced by fast and accurate autofocus and effective camera-shake correction.
Equipped with a built-in encoder, this lens has a power-enhanced 240 fps system that drives high-speed, high-contrast autofocus. Moreover, the Power O.I.S. system is able to compensate for both low and high frequency motion. The lens can also be used on camera bodies with built-in Dual I.S.2 shake correction. As a compensation system that works in tandem inside the camera and in the lens, Dual I.S.2 provides a superior level of shake correction.
Technical wizardry and what seem to be almost magical optical capabilities combine to give you the ultimate in photographic satisfaction. Additional features that make the lens a pleasure to use are the nine-iris diaphragm and a machined aluminum hood with a hairline finish that reduces reflection. Everything has been done to help you make the most of the superb performance of this high-end Leica DG lens.
[Technical Notes #1]
Potential realised by digital technology
The top element in the Nocticron 42.5mm F1.2 is an ultra-high refractive index lens with superb light gathering ability. UHR (ultra-high refractive index) lenses offer great potential for dealing with spherical aberration effects. Even so, they have long been avoided because UHR lenses have a yellow cast that colours the view through single-lens reflex optical viewfinders. In digital cameras, however, colouring can be easily corrected by digital processing. Technological advances have made lenses topped with UHR elements a great option for digital photography.
[Technical Notes #2]
Bokeh is not something people see with their normal vision.
During everyday life, people only see things in focus and have no awareness of bokeh. The out-of-focus blurring seen in photographs is not based at all on how we normally see the world. In photographs, the eye seems to want shapes to stand out as clearly as possible from the background. If there is a delineated subject, indistinct spots of light—that is, smooth bokeh—make the picture seem natural. Naturalistic bokeh is a great tool for photographic creativity, enabling expression of positive and negative feelings about a subject and allowing depiction of scenes with emotional resonance.