Smooth Backgrounds, Stunning Portraits: A Look at This Unique Sony Lens

The Sony FE 100mm f/2.8 STF GM OSS lens stands out due to its apodization (APD) element, which creates exceptionally smooth bokeh. Here's how it performs in practice.

Coming to you from Christopher Frost, this detailed video reviews the Sony FE 100mm f/2.8 STF GM OSS, showcasing its strengths and unique characteristics. This lens excels at delivering stunningly smooth bokeh thanks to its apodization filter. While its maximum aperture is technically f/2.8, the filter slightly reduces light transmission, meaning you’ll experience slower shutter speeds at brighter settings. Frost notes that the lens’ background blur doesn’t create the most out-of-focus backgrounds, but the quality of the blur is extraordinary. He highlights how the STF effect diminishes as you stop down past f/8, limiting its use to wider apertures.

Key Specs

• Focal Length: 100mm
• Maximum Aperture: f/2.8
• Minimum Aperture: f/20
• Lens Mount: Sony E
• Minimum Focus Distance: 1.87 feet (57 cm)
• Maximum Magnification: 0.25x
• Image Stabilization: Yes
• Optical Design: 14 elements in 10 groups
• Diaphragm Blades: 11, rounded
• Filter Size: 72mm
• Dimensions: 3.35 x 4.65 inches (85.2 x 118.1 mm)
• Weight: 1.54 pounds (700 g)

Frost explains the trade-offs involved with this lens. For example, the apodization element improves bokeh quality but can be less compatible with phase-detection autofocus, making it better suited for contrast-detection systems in mirrorless cameras. The lens produces a slight pincushion distortion. However, another standout feature is the lack of vignetting, even at wide-open apertures—a rarity for portrait lenses.

It balances well on a camera body, even with its relatively large size. Control points include an aperture ring, image stabilization switch, and focus hold button. Its sharpness and contrast are excellent across the frame, with only minor corner softness wide open. On APS-C cameras, the lens performs even better due to the smaller sensor taking advantage of the lens’ sweet spot.

Frost concludes that while the lens has some limitations—like slower shutter speeds and a high price tag—it excels in its specific niche. If buttery smooth bokeh and sharp portraits are priorities, it's worth considering. Check out the video above for the full rundown from Frost.