Tiffen 405WSFX1 40.5mm Warm Soft/FX1 Filter

The Tiffen 40.5mm Warm Soft/FX1 Filter is a dual-effect photographic filter that merges a warming color shift with a light diffusion layer. The warming component adds a gentle amber tone to images, which is particularly effective for skin tones, giving subjects a healthy, natural glow without the orange cast that stronger warming filters can introduce. The Soft/FX1 diffusion smooths fine details like skin texture, pores, and small blemishes while preserving the overall structure and sharpness of the image — making it a practical in-camera alternative to post-production skin retouching.

As the lightest strength in Tiffen's Soft/FX line, the FX1 level is designed for photographers who want a natural-looking result rather than a heavily stylized soft-focus effect. It threads onto any 40.5mm lens, which is common on compact mirrorless cameras and some rangefinder lenses. Because both effects are combined into a single piece of glass, there's no need to stack separate warming and diffusion filters, reducing the risk of vignetting and image degradation on smaller lens diameters. The filter is best suited for portrait, beauty, and lifestyle photography where flattering skin rendition is a priority.