The HD Pentax-DA 55-300 mm f/4.5-6.3ED PLM WR RE lens is designed for use with K-mount DSLRs. The weather-resistant zoom lens provides enhanced autofocus (AF) and outstanding optical performance in a compact and lightweight package, says the company.
The lens provides an effective focal length range of 84.5-460 mm when mounted on an APS-C format camera. Its design enables quiet, high-speed AF operation in still-image shooting, as well as smooth and quiet AF tracking operation during video recording, with minimal mechanical noise created by focus and aperture shifts, notes Pentax.
Coated optics are said to deliver sharp, bright, high-contrast images free of flare and ghosting.
Closest focus is 0.95 m (37.4 inches).
With a fully retractable design, the lens measures 89 mm (3.5 inches) long when retracted, and weighs less than 442 g (1.0 lb).
The lens is fully weather-sealed.
With the adoption of a rear-focus system, the lens is almost 10 percent lighter than the previous model. By driving this focusing lens using a pulse motor (PLM), which is directly linked to a lead screw, this zoom lens also operates faster – approximately 8.3 times at its wide-angle end and approximately 1.7 times at its telephoto end – and quieter than its predecessor. When mounted on the new K-70 body, it assures smoother, faster AF operation with dimly lit subjects, says Pentax, thanks to an improved AF algorithm that exchanges AF data between the camera body and the lens with greater precision. Operability of its power-assisted focus system during manual-focus operation has also been improved. The company notes its distance ring is designed to accurately detect the angle of rotation and swiftly react to a change of angle, therefore this zoom lens can shift its focusing lens smoothly in response to distance ring operation.
The company also notes this is the first K-mount lens to feature an electromagnetic diaphragm control system to assure smooth, high-precision aperture control during video recording. This system shifts the aperture setting automatically and smoothly to result in more natural, true-to-life videos, even when the brightness level of the subject changes drastically, such as a live theatre performance or a sunlight- streaked forest scene, or with active subjects such as athletes and animals. Coupled with the PLM mechanism, the system also assures smooth AF tracking operation and exposure control, while minimizing the intrusion of focus- and aperture-shift noises during video recording, says Pentax.
The lens features 14-elements in 11 groups, including an ED (Extra-low Dispersion) optical element to effectively minimize spherical and chromatic aberrations, while delivering high-resolution, finely detailed images with rich contrast from the image’s centre to its edges and minimal colour bleeding at any focal length setting.
Availability of the HD Pentax-DA 55-300 mm f/4.5-6.3ED PLM WR RE lens is scheduled to be announced in July.