- High-speed AF operation
- With the adoption of a rear-focus system, the focusing lens is 93.6 percent lighter* than the previous version. By driving this focusing lens using a pulse motor (PLM), which is directly linked to a lead screw, this zoom lens operates faster — approximately 8.3 times** at its wide-angle end and approximately 1.7 times** at its telephoto end —and quieter than the existing model.* When mounted on the new PENTAX K-70 digital SLR camera body, it assures smoother, faster AF operation with dimly lit subjects, 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. Since its distance ring is designed to accurately detect the angle of rotation and swiftly react to a change of angle, this zoom lens can shift its focusing lens smoothly in response to distance ring operation.
* When compared with the HD PENTAX-DA 55-300mm F4-5.8ED WR.
** When taking a still image in K-70’s viewfinder shooting, with the camera’s AF mode set to AF-S and for subjects positioned at a distance between 1.5 meters to infinity.
- Focusing Mechanism
- Lead Screw
- PLM (Pulse Motor)
- Focus Lens
|Phase-matchingAF AF drive time comparison|
|AF drive time|
|WIDE (55mm) TELE (300mm)|
|HD PENTAX-DA 55-300mm F4-5.8ED WR (The current model)
HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE (New model)
- Quiet AF operation and electromagnetic diaphragm control, perfect for movie recording
- This is the first K-mount lens to feature an electromagnetic diaphragm control system. When mounted on the new PENTAX K-70 digital SLR camera body, it assures smooth, high-precision aperture control during movie recording. Thanks to this state-of-the-art system, it shifts the aperture setting automatically and smoothly, even when the brightness level of the subject changes drastically in movie shooting. Coupled with the PLM mechanism, it also assures smooth AF tracking operation and exposure control, while minimizing the intrusion of focus- and aperture-shift noises during movie-recording operation. As the result, it produces more natural, true-to-life movies in locations such as a theater stage or a sunlight-streaked forest where the brightness level fluctuates considerably, and for such active subjects as athletes and animals.
Electromagnetic Diaphragm Unit
- High-quality images, with a minimum focusing distance of 0.95 meters
- With focal lengths from 84.5mm to 460mm (in the 35mm format), this telephoto zoom lens provides approximately 5.5-times zoom coverage from medium- to super-telephoto ranges. Its 14-element, 11-group optics include an ED (Extra-low Dispersion) optical element to effectively minimize spherical and chromatic aberrations, while delivering high-resolution, fine-detailed images with rich contrast from the image’s center to its edges and minimal color bleeding at any focal length setting. In addition to the short minimal focusing distance of 0.95 meters, made possible by the rear-focus system, the lens barrel has also been designed to be free of extension during AF operation, making it ideal for a wide variety of applications, such as outdoor, sports and landscape shooting.
- Compact telephoto zoom lens
- Thanks to its retractable structure, the lens is only 89 millimeters long. Since it weighs just 442 grams, it is extremely compact and handy to carry even in a limited space, such as a bag, making it ideal for casual, day-to-day shooting.
- Weather-resistant construction
- The lens features a dependable weather-resistant construction with 11 sealing parts to effectively prevent the intrusion of water into the lens interior. When paired with a weather-resistant PENTAX digital SLR camera body, it creates a durable, dependable digital imaging system that performs superbly in demanding shooting settings — even in rain or mist, or in locations prone to water splashing or spray.
- HD Coating to optimize image description
- The lens is treated with high-grade, multi-layer HD Coating.* Compared with conventional multi-layer coatings, this PENTAX-original coating assures higher light transmittance and less reflection to deliver bright, high-contrast images free of flare and ghost images, even under demanding lighting conditions such as backlight.
* HD stands for High Definition.
- Other features
- ・Quick-Shift Focus System allows the user to instantly switch to manual-focus operation, even when the camera’s AF system is in operation.
・SP (Super Protect) Coating applied to the front surface of the lens to effectively repel water and grease.
・Rounded diaphragm with nine blades to produce a smooth, beautiful bokeh (defocus) effect, while minimizing the streaking effect of point light sources.
- 【MTF Chart】
- Geometric MTF (MTF calculated without referencing the effects of light diffraction phenomenon)
- Wave optical MTF (MTF calculated referencing the effects of light diffraction phenomenon)
Spatial Frequencies S:Sagittal M:Meridional 10 lines/mm 30 lines/mm
- Since it is impossible to avoid light diffraction phenomenon on the actual lens, wave optical MTF is more realistic. However, geometric MTF is appropriate if you want to compare only the effects of geometric aberration correction on MTF.