I haven’t been into that for a decade but what my friends and I would do is make a diffuser to slip over our lights since high power dive lights tend to have a very tight focus. You can make a diffuser easily using anything from commercial diffuser material to a Pringels can lid. I cut mine to fit in a piece of PVC that slipped over my light head and held in place with a bungee chord so I could slip it on or off throughout a dive as needed.