Released near the end of 2008, the Pentax 55mm ƒ/1.4 SDM SMC DA* utilizes Pentax’s ultrasonic autofocus SDM (”supersonic drive motor”) system. SMC stands for ”super multi-coating,” a longstanding technology used by Pentax to reduce flare and ghosting as well as improve light transmission through the optical elements of the lens. The 55mm ƒ/1.4 DA* goes one step further by adding ”a newly developed Aero Bright Coating” which ”enhances image-description performance by effectively reducing reflections over a wider wavelength range.”
- The smc PENTAX DA Star 55mm F1.4 SDM is a prime standard lens that is ideal for portrait, still-life, or low light photography.
- Its fast F1.4 aperture offers outstanding depth of field control, and its rounded diaphragm blades create a more circular aperture for smooth, beautiful bokeh at large aperture settings.
- Adding the PENTAX Aero Bright coating on internal lens elements offers ultra high refraction index for improved light transmission with minimal ghosting and flaring
- The tightly sealed, weather-resistant and dust-resistant construction enhances durability for use in both rainy and dusty conditions, making the DA Star 55mm F1.4 SDM lens a perfect companion for the weather-resistant PENTAX DSLR bodies.
- The PENTAX-original Quick-Shift Focus System allows instant switching from autofocus to manual focus operation.
Conclusion – Pros
Good balance of optical properties for its intended (portrait) role
Near-silent autofocus thanks to SDM system
Very good build quality, including weathersealing
Conclusion – Cons
Relatively slow autofocus
Inaccurate focusing unless using camera’s AF adjust, varying in behavior across camera models
Very expensive for its class
The SMC-DA* 55mm f/1.4 SDM is a rather typical representative of the standard lens species – it is capable of delivering ultra-sharp results when stopped down a little but it’s also fairly soft at very large aperture settings.