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Sony DT 30mm F2.8 Macro Lens

Optical Characteristics

With a 35mm equivalent focal length range of 45mm, this lens offers a Standard Normal perspective.

Macro Lenses

True macro lenses have a magnification ratio of 1:1/ maximum maginification number of 1 or higher

Recommended Applications

Landscapes

Wide expanses and panoramas can be captured on the wide end of this focal length. For this application aperture settings will usually vary from f5.6 and smaller and cameras will usually be tripod mounted.

Interiors

Wide angle lenses are a must to capture the look of a room when working in confined spaces. This lens’s fast aperture allows you to capture as much natural light as possible and the camera will usually be tripod mounted to use slower shutter speeds.

Technologies

Circular Aperture

Circular lenses overcome the problem of defocusing of point light sources appearing polygonal and not circular through a unique design that keeps the aperture almost perfectly circular from its wide-open setting to when it is closed by 2 stops. Smoother, more natural defocusing can be obtained as a result.

Aspherical lens

Aspherical lenses minimize spherical aberration in all types of lenses, including large-aperture lenses. Aspherical lenses maintain high contrast in images taken with the aperture wide open, and effectively suppress image distortion.

ED (Extra-low Dispersion) glass

ED glass dramatically improves chromatic aberration at telephoto ranges, and provides superior contrast across the entire image, even at large aperture settings.

Multi-layered coating

Multi-layered coatings effectively suppress flare and ghosting over a wide spectrum of wavelengths.

Double telephoto zoom

Through the use of a telephoto type lens structure, the length of a fixed focal length lens can be made shorter than its actual focal length. A double telephoto zoom lens takes this principle of design one step further, by combining two such telephoto-type structures to produce a telephoto zoom lens that is extremely compact.

Floating mechanism

The floating mechanism compensates for lens aberrations by allowing groups of lens elements to move closer or farther apart, which makes it possible to correct various aberrations at practically all focusing distances

Internal focusing

Only the middle groups of the optical system are moved to achieve focusing, which leaves the total length of the lens intact. Benefits include fast auto-focusing and a short minimum focusing distance. Also, the filter thread at the front of the lens does not rotate, which is convenient if you’re using a polarizing filter.

Rear focusing

By moving only the rear group of lenses to focus, the lens allows for speedy AF operation and a shorter minimum focusing distance. Also, because the front of the lens does not rotate, operability is improved when you’re shooting with a polarizing filter attached.

Aluminum alloy lens barrel

Aluminum alloy is used in the construction of the G series and other high-end lenses to ensure high optical performance. This material is lightweight, durable, and highly resistant to the effects of temperature change.

Focus

Hold button Once focus has been adjusted on the desired part of the frame, pressing this button on the lens barrel will hold focus if you wish to recompose the shot.

Alternately, depth of field preview an be assigned to this button through the camera’s custom setting menu.

Focus range limiter

This function saves you a bit of time during AF operation by setting a limit on the focusing range. In macro lenses, this limit can be on either the close or distant range.

Distance encoder

The distance encoder is a lens component that directly detects the position of the focusing mechanism, and sends a signal to the CPU in order to measure distance to the subject. During flash photography, this data is very useful in calculating how much flash output is appropriate to the scene. The distance encoder plays an integral part in ADI flash metering, which delivers high-precision flash metering that is unaffected by the reflectance of subjects or backgrounds.

ADI flash metering

Advanced Distance Integration flash metering is available when the built-in flash, HVL-F56AM external flash, or HVL-F36AM external flash is used together with a lens that has a built-in distance encoder. It provides automatic metering that is virtually unaffected by the reflectance of subjects or backgrounds. Precise distance information is obtained through the encoder, and this data is used to compensate the flash output accordingly. This yields accurate exposures more reliably than conventional TTL (through-the-lens) flash metering, which can be thrown off by overly reflective or overly dark subjects and backgrounds.

SSM (Super Sonic wave Motor)

SSM is a piezoelectric motor that contributes to smooth and silent AF operation. The motor produces high torque at slow rotation, and provides immediate start and stop responses. It is also extremely quiet, which helps keep auto focusing silent. Lenses that feature SSM also include a position-sensitive detector to directly detect the amount of lens rotation, a factor that improves AF precision overall.

Specifications

35mm equivalent focal length range: 45mm
Lens perspective: Standard Normal
Minimum aperture: f22
Image stabilisation: In-camera stabilisation
Smooth AF motor: YES
Special lens elements: 5-6
Filter size: 49mm
Weight: 150g
Dimensions: 70 x 45 mm
Maximum magnification: 1:1
Recommended applications: Landscapes, Interiors