I know to some flashes are Satan's work on a Rangefinder, but for those who need to use one at night where a steady hand and low f-stop won't suffice..
I bought a SF24D a couple of months back to help with some fill flash and evening shots of friends. Whatever settings I tried it seemed to wash out the faces- The best I could do was dial down the exposure compensation to -3 as well as shoot manual flash settings, but still the light was ugly.
I read on a website that these Lumiquest Mini Softboxes can fit on a SF24D with a bit of jiggery pokery. They do indeed! now my fill and low light shots are far softer and I'm happy with the results!
I hope this helps others in a similar situation.