Laowa 105mm f/2 Smooth Trans Focus Lens - Pentax K

The Laowa 105mm f/2 Smooth Trans Focus (STF) for Pentax K-mount is a specialized short-telephoto prime engineered for the ultimate bokeh enthusiast. Often referred to as "The Bokeh Dreamer," this lens utilizes a unique optical design featuring an Apodization (APD) element. This element functions like a radially graduated ND filter—perfectly clear in the center and becoming denser toward the edges—which softens the edges of out-of-focus highlights to create a "creamy," melt-away background that traditional lenses cannot replicate.

Designed for full-frame Pentax DSLRs like the K-1, this lens provides a classic portrait perspective. It is distinguished by its dual-diaphragm system, allowing you to independently control the depth of field and the quality of the bokeh. While it offers the shallow focus of an f/2 lens, the APD element results in an effective light transmission of T3.2, ensuring that your subject remains tack-sharp while the background dissolves into a painterly blur.

Product Features in Detail

The "Smooth Trans Focus" Effect
The STF technology is designed to solve the problem of "distracting" bokeh. Standard lenses often produce bokeh with bright outer rings; the APD element in this 105mm lens ensures those highlights fade out smoothly from the center. This creates a more natural, three-dimensional look that makes your subject "pop" with incredible intensity.

Innovative Dual Aperture Rings
Unlike standard lenses, the 105mm STF features two aperture rings. One ring controls the T-stop, which affects the amount of light reaching the sensor and the intensity of the APD effect. The other controls the f-stop, which manages the physical depth of field. This allows you to fine-tune the "dreaminess" of your background without sacrificing focus control.

Elite Portrait Performance
The 105mm focal length is widely considered the "sweet spot" for portraiture. It offers a flattering compression of facial features and a comfortable working distance between the photographer and the subject, making it ideal for everything from fashion to intimate headshots.

Apochromatic-Like Clarity
To ensure that the "soft" background doesn't result in a soft subject, Laowa utilized extra refractive index glass. This minimizes chromatic aberrations and color fringing, ensuring that even when shooting wide open, your subject’s eyes and fine details remain crisp and clear.

Exceptional Build for Pentax Users
The lens is built with the same "tank-like" quality that Pentaxians expect. The all-metal construction and weighted focus ring provide a tactile experience that is perfect for the slow, deliberate process of high-end portrait and still-life photography.

Versatile Macro-Portraiture
With a minimum focus distance of 3', you can capture tight compositions with a 0.16x magnification. Because the bokeh is so controlled, this lens is a fantastic choice for nature and floral photography, where you need to isolate a single petal against a complex, busy background.