Tiffen Filters
Why You Should Try Diffusion Filters – Comparison & Review
Ryan Filgas
For portraits, having a high sharpness may not always be what you want as it exposes "imperfections" in the face and makes retouching work more difficult as well; that's where a diffusion filter comes in. It allows highlights to bleed into the shadows making smoother transitions, and softens the skin for a more "pastel" look.
