Well guys, check this clip
(done at f2 on my f1.4 50mm) I've been doing testing all weekend..and arrived at this. I'm actually a bit shocked, as I figured specular highlights could not be done this way through a diffuser, without a growing "halo". I've figured a way to have the unit allow either "straight" brevis sharpness/light gain/diffusion, vs this look. The adapter loss is 0 f/stops with this option, and .5 stops gain
in "stock" config.
If I go ahead, the user could potentially choose the diffusion level. The change would take approx 5 minutes..or less, even for a newby.
So with my f1.4 lens attached, we're looking at total "system" loss of 1 stop (diffusion cranked) or .5 stops (stock setup) total loss respectively.
Your existing setups can be mod'd for this. Factor about $100-$150 to add it. I need to do further testing with the achromat and some higher res stills before I'd make this a certainty.
Andy gets all the credit for getting me thinking on this