I've tried searching around for DC Fix and although I've found it mentioned a few times I can't figure out what it is besides some kind of tape or film that you put over the lens. Could you enlighten me please? Thanks.
DC Fix is a contact paper designed to provide light diffusion on bathroom windows. it's textured polyurethane backed by heat and moisture resistant adhesive. the main US vendor for this stuff seems to be
Berlin Wallpaper who sells the stuff in rolls, but a couple guys at CPFMarketplace sell small sheets of it pretty cheap. when used on glass, it goes on easy and comes off pretty clean. when applied to the lens of a flashlight that has a reflector, it just about doubles the size of the hotspot, blends it better with the spill, and softens the hard edge on the spill with only a minimal loss of output.
when i tried it on a Xeno E03 XML, it basically turned the beam into a wall of light. the hotspot on the Xeno is already pretty big and diffused, and the DC Fix made it so that i really couldn't tell the difference between hotspot and spill anymore. about 1' from a whitewall, i could tell a little, but 10' away and farther, i couldn't tell a difference.
when i tried it on a P60 XML, the difference between hotspot and spill was a little more noticeable, but when outside and looking at anything more than a few feet away, it was hard to tell. it wasn't the seamless wall of light i got from the Xeno, but it was still pretty floody and diffused.
the reflector on the Xeno is 18-19 mm wide. the reflector on a P60 is like 26-27mm wide. i don't have a H600 but i think the reflector is somewhere in between those two in size and i assume the beam is about half way in between those two. if that's true, the DC Fix would still leave the H600 with a little bit of a hotspot up close but it would probably be very hard to notice when looking at things 10 feet and farther away outside. it should be very effective at turning the H600 beam into a not-quite-but-almost seamless wall of light.
btw, i'd be pretty surprised if the hotspot on the H600 was actually 12 degrees as Zebralight claims. it looks a lot bigger than that in the beamshots i've seen. plus, the hotspot on my P60 XML which has a much wider and deeper reflector was around 15 degrees. i don't think the H600's hotspot would be smaller than that.