As Rob pointed out, the silver, even with the white defusion panel is a more directional light source.
This image was made with the 86" and defusion panel. It was almost floor to ceiling and I was in front and just a bit to left of the PLM. It is the only light source.
The great thing about the PLMs is that the silver delivers one kind of light, the silver with defusion another and the white with spill kill another.
I like the white with spill kill because it has a chinese lantern kind of effect with the light radiating out in a broad arch. Makes a nice fill or soft side kicker and with a little care delivers a consistent F-stop for a full length or group.
The head and shoulder shot of the blonde illustrates how the white with spill kill can soften the silver with defusion for nice soft transitions. Along with enough directionality to provide modeling.
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