Originally Posted by
Saracen
No, your terminology is correct, and the Stofens, Wong Lightspheres, mini portable softboxes, etc, are all diffusers, and known as such.
Bobster's comment was, I assume, pointing out, if a tad flippantly, that you can also use convenient light surfaces, like walls, ceilings, etc as a diffuser. After all, if your flash fires directly at a subject you get harsh lighting. But if you bounce it of a convenient nearby surface, you get a far less harsh, less directional, diffuse light.
It's something of a debate between the more purist element, and the gadget conscious. In my view, both camps have a point, and both approaches have their merits.
And, for that matter, many diffusers can be home-built, with varying combinations of wire, cardboard, tracing paper, etc, and a layer (or two) of tracing paper and a rubber band will achieve much the same result as a purpose-built Stofen.
In my defence, on the MT-24, I can fit or remove the Stofens to both flash heads in about three seconds each, and don't have to worry about losing the rubber band. And, given what the flash cost, the cost of the Stofens wadn't exactly a major concern.