I saw a diver with an immensely powerful focus lights..more like 8K to 12K lumen power.
He was on a black water dive with us with his own guide and got some really nice images.
Does one need such a powerful search light/focus light ? He was on a reef night dive with us too and to face him was to loose your sight for the next few minutes.
Is this really a necessity or an overkill?
Diggy