Handheld Primary Light Options (Cave)

[tbone1004]

Mike was looking for a new canister light and a friend of his showed him the orca torch 630. He bought one and has been using it for a while now. Pretty sure he is using it in Cozumel this week. Just sayin.

and for $650, it's a perfectly adequate light, but it's not anything close to what it claims it is.
5 hours on an 89wh canister means an average consumption of 17.8w which makes it somewhere around a 2000 lumen light, not a 4000 lumen light and probably has a burn curve similar to that of the Big Blue. It's one I recommend to students that need/want a can light for various reasons but can't shell out for a big boy light

Has Mike been using it for the Roaring River project?

he may have, but the deep dive was done with a light monkey

 

[Gone for diving]

please explain to me how measurement of power consumption is more accurate for brightness than a measurement of the total amount of visible light? You can back into lumen output but you need the rating of the emitters which is lumens/watt and then you need the total efficiency of the system *losses in the drivers, and then the optical efficiency of the lens itself which BB has very cheap lenses that are not particularly efficient*.
Now, I gave you rough watt consumption for that light, it is an average, and there are many assumptions being made, but if you have a 50wh pack that burns for 3 hours, then it's a 50/3=16.6w light. Problem is you can't discharge those batteries to 100%, and there are all sorts of efficiency losses that have to be factored in.
IF they get their 3800 number, it's for a brief second immediately as the light turns on and then it falls off like the chart in the picture. The batteries can't supply that much power for very long. If it was a true 3800 lumen then it would have about a 30min burn time on high.

Watt consumption is fine if you are comparing lights from the same manufacturer, i.e. the LD-40 and the LD-20 which are engineered the same and you have the same variables at play, but it's not fair to use those same values when comparing lights from different manufacturers and here's why.
Companies like UWLD, Dive Rite, Light Monkey, Light and Motion etc. all use constant output drivers. I.e. they consume about the same amount of power from start to finish and as such have a relatively constant light output. You can see this in the chart I posted from the LX20. When you look at lights from manufacturers that aren't quite so honest about their lights performance then you get lights like from Big Blue where they do not use constant output drivers and the out falls off drastically which is why I used the term "average" because you have not idea what the watt consumption is from start to finish. We can back into an average watt draw with some assumptions, but we can only use that as an average over the duration.

One last point about why watts are a bad unit to use. LED's have all sorts of different efficiency values depending on what is being done with them. LED's efficiency is based on the power being sent to them and it falls off as they get hot. Some manufacturers under-drive their lights to improve efficiency, and some over-drive them to maximize light output. That value can go all over the place from as low as 60lumen/watt all the way up to about 120lumen/watt which makes a comparison based on power consumption all but useless when you are comparing manufacturers or heaven forbid different generations of lights *The original LM 12W LED for example was only about 450lumen total which is less than 40 lumen/watt.
If a manufacturer claims lumen, it's the right unit to use to compare, but you have to be smart about it because Lux is also important which is the intensity of the beam in the middle. Video lights for example have very low lux, but very high lumen because there is no hotspot and it's quite wide. A laser pointer has high lux but low lumen so it's all a balance, but watts is not the right unit to use when comparing lights to one another because of the wild variation in efficiencies.

Yes for in depth analysis lux and lumen is the correct way,

I might have to invest in an other tool,

Often, what led is used is advertised,
So spec can be gotten from that,

I often mount led on off road equipment,
Try comparing work lites, it's near impossible, everyone uses different numbers, and lie on their specs,
Comparing is usually best, and checking amp draw and figuring out watts, is fairly accurate way of comparing, I realize not perfectly accurate, but sure gets you in a ball park, but it's a good way to explain to customers,

I say LEDs are always improving, and everyone its updating to a new type of led,
So yes if you compare an old led verse and newer version, it will be out,
But in general input vs output is somewhat close, (an over driven led is a problem for me, it's not reliable enough for me, kinda defeats the purpose, a bit under driven is what I want)

Reflector, glass, probably has a lot more to do with lumen output as well,

 

[tbone1004]

@Rol diy optic efficiency especially when submerged is huge when measuring total lumens out the front. Doesn't matter what is coming out of the emitter if you can't collect it properly which is part of why the light heads from Light Monkey and Halcyon are so big. They don't want to spend on custom optics so they have to make those massive heads to get it to work properly.

 

[kensuf]

While I've gotten significant discounts on stuff, I've never been given a light. I guess I don't rate.

 

[rddvet]

While I've gotten significant discounts on stuff, I've never been given a light. I guess I don't rate.

Wow. We can’t be friends anymore.
I bet if you started posting your location on Instagram and fb every day and make it look like you’re doing crazy insane dives day in and day out you’ll get some swag. I can’t point you to a few people in cave country who you can emulate.

 

[kensuf]

Wow. We can’t be friends anymore.
I bet if you started posting your location on Instagram and fb every day and make it look like you’re doing crazy insane dives day in and day out you’ll get some swag. I can’t point you to a few people in cave country who you can emulate.

Maybe you're right. I did 5 days of diving in Curacao and not many people realized I wasn't just sitting at the beach and drinking beers.

 

[tbone1004]

Maybe you're right. I did 5 days of diving in Curacao and not many people realized I wasn't just sitting at the beach and drinking beers.

I get them because of the university, but @rddvet is right, you post too much bikes and dogs eating taco bowls, not enough cave porn

 

[kensuf]

But I'm with cave divers when feeding dogs taco bowls.

 

[Whitrzac]

If mike young uses it…it’s good enough for me….

They're now called 3800 lumens, so let's do some math.

Battery is 4x 18650's, optimistically that's 3.6v*3.5ah*4cells=50.4wh battery pack and we will be generous and say that it's 90% usable which is 45wh available.
Big Blue claims 3 hour burn time which from history we know is something they don't lie about because their customers can measure that.
3 hour burn with 45wh battery means an average of 15w consumption.
Best emitters out there are going to be about 170 lumen/watt, and they aren't using those emitters, but we will assume they are because they seem to think their lights are full of magic.
170*15=2550 lumens average during the 3 hour burn time. But wait, their literature says it's 3800 lumen for 3 hours, how is this possible? Guess what, it's not, they have lied about the output of every light they have ever made, as well as selling canisters that were allegedly un38.3 compatible but still exploded and almost killed a diver, so there's that.
Now that 2550 lumens is assuming 100% efficiency, using the highest quality emitters possible. The reality is that they're probably using emitters at around 110lumen/watt and the optics are only about 80% efficient at best, so 110*15*.8=1320 lumen average which holds true with the testing that has been done about their output which look like this.
View attachment 698652

Compare that to the Dive Rite LX20 which has a constant output driver and I'll take the one that says it's an 1100 lumen light and puts out 1000 lumen, vs the 4000 lumen light that only puts out 1100 lumen after 30 minutes.
View attachment 698654

Where did you get these graphs/ who did the testing?
I wish there was more info like this out there

 

[tbone1004]

Where did you get these graphs/ who did the testing?
I wish there was more info like this out there

We Test Lights | Independent Tests, Reviews and Technical Comparison of LED Lights

wetestlights.com

It is admittedly owned by Light and Motion but if you read the FAQ it shows their process and how they keep it fair. It is in a certified test environment though, so it is data that can be trusted.