Both are diffusion type filters but DIFFUSER gives a soft-focus effect due to its irregularly uneven surface while DUTO has fine concentric lines etched on its surface.
The center of the picture is usually sharp with DUTO but DIFFUSER gives an overall soft-focus effect.
Hoya 62mm Diffuser Glass Filter
Features - Hoya 62mm
Diffuser Glass Filter
Provides an overall soft-focus effect
Works with lenses that are threaded for
Well suited to use for portraiture and
High grade material construction for
durability and precise functionality
Has a soft-focus effect due to its
irregularly uneven surface while Duto has fine concentric lines etched
on its surface
Also act as general protection filter to
reduce dust, moisture, and scratches from reaching lens elements