HOYA 52MM "Diffuser" Diffusion Filter The Hoya 52mm Diffuser screws onto the end of any 52mm filter size SLR lens The Diffuser lens the image a soft-focus effect, due to its irregularly uneven surface Unlike Duto filters, which render images with the central area sharper than the borders, the Diffuser provides an overall soft-focus effect Particularly effective in portraiture and commercial photography