Primary Light for cave diving?

[CAPTAIN SINBAD]

Big Blue VL15000P LED Pro Mini Tri Color Video Light & Case

This is the biggest one I know of.

 

[EireDiver606]

How many Lumens do you prefer? There are some 15000 beasts out there but are they popular?

Lumens don’t give the diver anything useful to work with. Most claimed lumens ratings are just that. “claims”. They start off at the lumens maybe and very very quickly drop or else they’re simply lying completely. Lux is the real measurement. After hearing @tbone1004 I understood it more, he will be able to help you out here.

Hey @kensuf how do you like your Focus 2? Is it worth the big bucks?

 

[Brian G]

Doing some math on the 15000 lumen claim, I see 7 x 18650 batteries lasting for a claimed 2 hours on high. If we assume the highest capacity 18650 batteries (3.5 amp hour) and a very generous average voltage (3.6 volts), then the total available watt hours is 7 batteries x 3.5 amp hours x 3.6 volts = 88.2 watt hours. If the battery life is two hours, then that comes out to 44.1 watts. The XML-2 leds they claim to use have a MAXIMUM efficiency of 170 lumens/watt. So at the very most optimistic estimate, it will be 44.1 watts x 170 lumens/watt =~ 7500 lumens. Max. Curiously almost exactly half of claimed. Note that I seriously doubt that the leds are being run at their most efficient power point, but at least with 32 leds they are not claiming that every led is putting out the max output, which several companies do.

 

[tbone1004]

@Brian G and that math holds true for almost all of the BB lights. The average lumen across the total burn time is about half of the claimed lumens. It starts off brighter than that, usually around 3/4 of the claimed lumens but falls off quick. It's fine if you're an educated consumer and treat the lights for what they are, but most people are not which IMO falls under false advertising claims. I much prefer constant output drivers personally. A lot less burn time, but more useful and consistent light.

 

[Reku]

I use an uwld35 - it works well. I run it on medium or low.

 

[_Ralph]

Another fan of the focus 2.0


_R

 

[wetb4igetinthewater]

Trying to find the Big Blue light and the model I'm finding doesn't appear to be a canister, I've been able to find the other mentioned lights. Is there a canister version of the BB or is a non-canister primary acceptable for cave usage? Looking for a light with longer run-times for wreck diving and would like to get something that would be compatible with cave if I ever decide I have an interesting in pursuing cave.

There was a recall for the Big Blue canister lights (I had one and turned it in) and Big Blue no longer sells any such lights.

 

[JohnnyC]

Big Blue VL15000P LED Pro Mini Tri Color Video Light & Case

This is the biggest one I know of.

That's a video light. That's not a primary light. You're gonna have to fling that thing around like a meth-addled cat to even come close to signaling with it. And it's useless with particulate in the water.

 

[tursiops]

Big Blue VL15000P LED Pro Mini Tri Color Video Light & Case

This is the biggest one I know of.

That is a video light. You do not want that in a cave as your primary...can't signal with it, and too often in someone else's eyes.

Added:
There is an echo in here.....

 

[helodriver87]

For my money, you can't go wrong with Light Monkey or Halcyon. I use a LM 32W VF LED as my primary. It's fantastic in clear water. Head and shoulders above the Focus. That thing lights up a cave better than anything else I've ever used. But when I get into darker water or places with lots of particulate, I find myself a bit jealous of my buddy's Focus 2.0. The "punch" is significantly better. Ideally, I'd own both. It's just not high on the list of priorities right now. But you can't go wrong with either. Build quality and service after sale are top notch with both.