The Olympus FL 36 "appears" to work fine on the D LUX 4. (I'm not sure yet if all the auto functions of the flash are operational but will report back later.) It just looks a bit strange because of size. (Even though the FL 36 is a fairly compact flash.) By the way, if you're not familiar with this unit the head "twists and turns" in a number of different directions allowing for a a variety of bounce scenarios. I use mine with an Omni bounce. Flash -
Olympus FL-36 Flash: Digital Photography Review .
Omni Bounce -
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. . . Burkey