Anybody making 30 to 60 thousand lumen dive lights? Besides Big Blue??

[tursiops]

Not a MAJOR cost to make them work underwater at all. Simple housing, couple of O rings and a magnetic switch.

I know this because we build some of our products to be used in tanks for underwater sets powered by 240V. Since no-one's been electrocuted I think I know what I'm talking about on this subject

Forgive me for being skeptical. Very skeptical.

 

[Diving Dubai]

Forgive me for being skeptical. Very skeptical.

Just admit that on this subject you're in over your head and be done with it.

 

[tursiops]

Just admit that on this subject you're in over your head and be done with it.

LOL. Just admit that in terms of making your case you are in over your head and be done with it.

 

[Angelo Farina]

I say nothing about costs.
But regarding the concept that the luminous flux (which is measured in lumens) decreases with the square of distance, this is plainly wrong.
What decreases with the square of distance is another physical quantity, called illuminance, and measured in lux.
One lux is one lumen divided one squared meter.
So, if a given luminous flux, say, 1000 lumen, is propagating inside a cone with a certain angle, say 65°, so that at 1m distance the area of the cross-section of the cone is, say, 0.5 m², you will get an Illuminance of 1000/0.5=2000 lux.
You go further away, at a distance of 2m, where the cross-section area is 4 times larger (2 m²), and the illuminance will be 1000/2=500 lux. The illuminance is now 1/4 of the previous value, but the luminous flux remains the same (1000 lumen)...

What characterises the output of a light source is the luminous flux (lumens). So a claim of generating 35000 lumen from a power source capable of 360W is a reasonable value, as we know that decent LED sources usually are around or exceed an efficiency of 100 lumens/watt.

There is a third quantity characterising how the luminous flux is spread in a narrow or wide beam, and this is the luminous intensity I, measured in candelas. I is the ratio between the luminous flux and the solid angle of the beam (measured in steradians, not in degrees).
Given a certain luminous flux, the luminous intensity will be larger if the beam is narrower.
Also luminous intensity does NOT decrease with distance, apart the case of light propagating in an absorbent medium (such as dirty water).
In this video you can see an explanation on the cause-effect relationships between luminous flux, luminous intensity and illuminance:

 

[Graeme Fraser]

I disagree. But if they can convince people to buy it, good luck to them

Firstly they're claiming ONLY 82% CRI on a 5600K array. That's rubbish, I mean seriously rubbish. Anyone who isn't getting above 90% on either 5600K or 3200K on their units should reconsider their supply (and design)

This is 2012 array technology.

I actually do know how much arrays cost (remember all arrays are basically brought from the same few suppliers). They have advertised 35000K (how many people actually have a test bench?) Yes it's a "big" number because it's measured at the surface of the array - but it's' of no consequence

If it was, Our big light which achieves the 35000 lumens at a distance of 10m/33' away we'd instead advertise as being a 20,000,000 Lumen fixture (becuases that's the theoretical total output of the arrays measured at the surface. Inverse Square Law applies

At the subject distance of 1-2m apply the inverse square law you're down to a Theoretical 1093 lux/lumen/m2

And this is what really upsets me. Because this light won't ever achieve this output, since it has no optics. Which are incredibly important to achieve output at the required distance

I bet a significant amount that this light won't achieve anything like the output at the subject. Its output will drop off a cliff

Why do I keep banging on about subject? Because measuring the light actually at the subject distance is the only true measure.

No one quotes it, because they want a headline number and they don't want to admit how crappy their lights are by showing an actual measured output at distance.

Basically. Buyer Beware These quoted Lumen numbers are meaningless

As a comparison I can sell you 2 professional TV lights that each achieve an actual 1500 Lumen at 2m for less than the price of this dive light (I assure you ours have a lot more tech behind them).

We actually have a small battery powered unit (designed for mounting on small DSLR type cameras) that puts out more light than this and at a much cheaper price (with CRI +96%).

We could turn it into a dive light but the market is too small for us to bother

Interesting. Similar to how some motorcycle manufacturers would measure BHP from the crank rather than the wheel I suppose.

Just for the record, I'm definitely out of my depth on this subject.

 

[OTF]

Great post @Angelo Farina

 

[rjack321]

This looks as a serious product. All the data supplied are perfectly consistent. Three battery packs of 100 Wh each (300 Wh total), meaning a 360W output for 40 min, and 35000 lumens (just something less than 100 lumen/watt, which is perfectly credible).
Of course, also the price is "serious".
The point now is if one really needs such a powerful light source...

I have never seen one ( I mean look at the price)

But I could tell from the power, the battery size and the burntime that it was at least roughly 30,000+ lumens on high. The wattage on the bigblue lights just doesn't align with their purported luminosity.

For National Geographic specials in gin clear water with 8K camera or something similar - I guess they want that much light, and they have the budgets to afford the lights. With a headmounted gopro in the mud? The op is wasting money on something this powerful.

 

[Calabash Digger]

The OP aint spending no 4 grand on a dive light to lay in the mud....

 

[Manatee Diver]

If you really want that powerful of a video light you can get it but you won't like the price and it won't magically make the water clear.

Keldan Video 24X FLUX 35,000 Lumen Underwater Video Light (backscatter.com)

Dear Santa,

I've been a good boy this year, I would love to see a pair of these under the tree this year.

Sincerely,

Manatee