Pentax *ist DS SLR Review
Lens Mount, Lenses, AF System
The *ist DS uses a Pentax K lens mount used in conventional 35mm-format SLR cameras, the *ist DS accepts a large number of existing 35mm-format interchangeable zoom and special-application lenses and accessories to help accommodate diversified photographic requirements and maximize creativity and image quality.
Compatible with Pentax K, KA, KAF, and KAF2 mount lenses; screw mount lenses, 645, and
67 series lenses (adapter required). Some restrictions and conditions may apply to
certain lenses and accessories, see chart below.
The "heart" of the *ist DS is an APS-sized CCD image sensor with an effective 6.1 million pixels. The effective sensor size is 23.5 x 15.7 mm with the same 3:2 aspect ratio of 35mm film. The *ist DS's CCD (on the right) is compared in size to a 5-megapixel 2/3-inch CCD imager.
Because the imager is physically smaller than 35mm film
the angle of view is 1.5x the normal lens focal length. This makes going ultra-wide a
challenge but it yields longer telephoto focal lengths with no reduction of maximum
aperture. The 75-300mm zoom becomes a 120-480mm lens!
PENTAX Develops the New DA Series of Interchangeable Lenses for Its Digital SLR Cameras
PENTAX Corporation is proud to announce that it is currently in the final stage of development of the compact, high-performance smc PENTAX-DA series of interchangeable lenses, exclusively designed for use with PENTAX digital SLR cameras.
The image circle in the DA-series lenses is designed to perfectly match the size of the
CCD (23.5mm x 15.7mm) incorporated in PENTAX's digital SLRs, optimizing the performance
of these cameras. The new design also contributes to a drastic reduction in size,
weight and production cost, compared to 35mm-format counterparts with similar
PENTAX-DA Zoom 18-55 Perfect Fit For *ist DS
Mounted on the PENTAX *ist DS, this zoom lens provides an angle-of-view equivalent to a 27.5mm-84mm lens in the 35mm format that covers the most frequently used ranges from wide angle to moderate telephoto.
The aspherical optical elements in this new lens contribute to a reduction in size and weight of the lens and to more effective compensation of unwanted aberrations.
The aperture ring has been eliminated from this lens to simplify camera operations and improve appearance while aperture-setting operation is performed from the camera body.
Quick-Shift Focus System
Once subjects are captured by the camera's autofocus system, this PENTAX-original system allows photographers to shift the focusing mode instantly to manual without any switching operations.
PENTAX P-FA J 18-35mm F4-5.6
Announced last year is the smc P-FA J 18-35mm F4.0-5.6 AL wide angle zoom lens for use with PENTAX 35mm-format autofocus SLR cameras. Featuring an ultra-wide 100-degree angle of view at the 18mm focal length, this compact interchangeable zoom lens produces high-quality images with minimal aberration, thanks to the incorporation of an aspherical lens element.
Featuring a simple, functional design without an aperture ring, this compact, high- performance zoom lens measures only 72 millimeters (2.8 inches) in diameter and 68.5 millimeters (2.7 inches) in length and weighs a mere 190 grams (6.7 ounces). It also features an angle-of-view coverage between 63 and 100 degrees and a minimum focusing distance of 0.28 meters (0.92 feet) for a maximum magnification of 0.18 times. It comes equipped with a lens hood to cut off excessive light and minimize flare and ghost images.
When mounted on the new PENTAX *ist DS digital SLR camera, this zoom lens offers focal
lengths equivalent to 27.5mm~53.5mm in the 35mm format to cover wide-angle to standard
PENTAX-DA Zoom 16mm~45mm F4 ED AL
The compact, high-performance, interchangeable smc PENTAX-DA 16mm-45mm F4 ED AL lens features a 3X zoom ratio with focal lengths covering ultra-wide to moderate-telephoto ranges for the angle of view equivalent to 24.5mm-69mm in the 35mm format.
The DA-Series features a responsive "Quick-Shift Focus System" that allows photographers
to instantly switch the focus mode from auto to manual with a slight twist of the focus
ring. Coupled with a simple, functional design and the elimination of an aperture ring,
this new mechanism considerably improves the camera's operability. The lens also
incorporates an Extra-low Dispersion (ED) glass lens element and two aspherical lens
elements for true-to-life image reproduction and overall size reduction. The image circle
in DA-series lenses, including the smc PENTAX-DA 16mm-45mm F4 ED AL, is designed to
perfectly match the 23.5mm x 15.7mm size of the CCD used in PENTAX digital SLRs to optimize
camera performance. The new design also contributes to a drastic reduction in size, weight
and production cost, compared to 35mm-format counterparts with similar specifications.
smc PENTAX DA 40mm F2.8 Limited
The smc PENTAX DA 40mm F2.8 Limited lens. Designed for exclusive use with PENTAX digital SLR cameras, the unique pancake style standard lens measures a mere .59 inches in length and weighs just 3.17 ounces. Combined with the popular PENTAX *ist DS digital SLR, the PENTAX DA 40mm F2.8 Limited lens will offer the smallest and lightest digital SLR combination available from any manufacturer.
Featuring a sophisticated appearance that incorporates an aluminum lens barrel, hood and cap, the lens offers a perspective similar to the naked eye with its 40mm focal length (equivalent to 61mm in the 35mm format), a large maximum aperture of F2.8, and a minimum focusing distance of 40 centimeters.
The PENTAX DA 40mm also features the PENTAX Quick Shift Focus System for instant switching to manual focus operation, a nine blade diaphragm to assure true-to-life reproduction of out-of-focus areas, and filter attachment versatility (a 49mm-size filter on the lens or a 30.5mm-size filter on the lens hood).
The *ist DS employs the SAFOX VIII TTL phase-matching autofocus system, the camera's 11-point AF sensor covers a wide area of both horizontal and vertical image fields with exceptional speed and precision even under poor lighting conditions. Nine of the 11 AF sensors are a horizontally extended, cross-shaped type, improving focusing accuracy and aligned to effectively cover the middle section, while two additional sensors are positioned at each side of this section. The selected AF sensor point is highlighted in red in the viewfinder for easy visual confirmation.
In addition to the versatile "Auto" mode and the pinpoint "SPOT" mode, the *ist DS offers the innovative "SELECT" mode, which allows the photographer to select one of the 11 AF sensor points using the four-way controller on the back panel. The user-selected sensor point is superimposed in the viewfinder with a red LED indicator. Focus modes available are AF-Single, AF-Continuous and Manual. Focus lock available. The working range of the AF system is from EV0 to EV19 at ISO 200.