MichaelTapes wrote:
ND on the lens is not a good solution for me simply because I would need them for many lenses. I think ND gel on internal diffuser makes the most sense, since it accomplishes exactly what I want and that is to have less light from 1 specific source.
I have not tried this yet, but any thoughts on aluminum foil on the internal diffuser facing back at the light. Not the entire diffuser, but just the center area. Would kind of act like the light block in a beauty disk, where all of the light would be bounced around a little more. Might change the quality of light, and would certainly affect the uniformity of the light across the surface of the SB. I might do some experimenting just for kicks :>)
I personally wouldn't stick foil in there.  How about hitting the dome with a coat of high heat white spray paint?  I'm not sure of the texture on the Einstein dome, but if one side is shiny, hit that side that way if it doesn't work it can easily be removed with a mild solvent?  If it works, just order another dome diffuser so you have one of each.  I dunno that it would kill much light but then again I'm trying to figure out how you're not able to shoot at f2 or so @ISO 100 with those lights.
How many lenses do you own that open up to an aperture where you'd need to lower the output of a 2.5ws light?  
I have one filter and one adapter, it covers three lenses.