Diving Light recommendations

[Patoux01]

On 160°, it's a flood light, so you don't want a fringe. Yes people would notice if 90% of the light is focused in the central 80°, and so would the cameras, as 80° is less than the field of the camera, ie you would have "clipping" effect where the sides are dark.

Price has nothing to do with accuracy. My job had me build a testing rig for 200$ for computer mice, it was more accurate than their > 20k investment, more repeatable as well. So yeah, no. Theirs also proved to be way off when I took a deeper look into it.

The issue of affiliation BDSC mentions is one we had as well. People will have a tendency to not trust you when you run tests and surprisingly only your product passes the tests, or your products consistently perform better. Which is obviously an issue, so unless other people confirm the results, spoon of salt (this is true for most things).


At the end of the day, I still trust the "place them side by side and turn them on" approach more.

 

[tbone1004]

I did a quick look into the link tbone supplied about the light testing. From what I can tell, the testing group seems to be affiliated with Light & Motion. If you look at their test results, it seems that every L&M light exceeds their specs and most other brands fall short. You have to wonder just how objective the testing is.

there isn't much objectivity to it though. Big Blue is not able to produce lights to their claimed specs. It is WELL beyond the technology available today. 7x XML's are capable of producing 3100 lumens, but a single 32650 is not capable of driving them which is why they can't reach their claimed lumen output.

32650's are optimistically rated at 6000mah which is 22wh. Lighting technology is realistically capped at 120 lumens/w. They claim 90 minutes burn which means the light is pulling an average of 14.6w. 14.6*120 is 1752. Around what you see the average of the curve in the L&M testing. To get 3100 lumen for 90 minutes out of a 22wh battery, you can still only pull 14.6w if you use the entire battery capacity and that means their efficiency has to be better than 210lumen/watt. That is WAY beyond our technology. This is not including any efficiency drops from a boost driver which it needs because of the voltage drop of the single battery cell, it is not including any other efficiency losses in the lights either. Typical total efficiency is around 90% with some well engineered lights like UWLD and L&M exceeding 95%.

So. Is L&M failing to do objective testing, or are they being honest with their specs as opposed to other manufacturers who are grossly exaggerating theirs?

@Patoux01 the big blue 15000 does not get anywhere near 160* and their 80* claim is fairly accurate. I have had it in the water next to a light and motion and a UWLD. L&M claims 90* and UWLD claims 120. The BB and L&M were essentially the same and the UWLD was noticeably wider. The UWLD has a very harsh cutoff because the optics were designed to have no fade. It's been a critique of their lights since there isn't a soft edge. L&M had a soft edge, but was even across the beam. BB had a hot spot with a wide but faint corona. That may be where they are claiming the 160, but in the water, it was similar to the L&M.

You can't build an inexpensive lumen tester. You can't. Don't care how good of an engineer you are, you just can't do it. They look like the picture below, and are very big, very expensive, and very uncommon. Most manufacturers measure the power draw, know what the expected efficiency should be, and quote a nominal value. L&M is to my knowledge the only divelight manufacturer that has invested in this equipment and everyone else uses nominal values which is fine. My issue with BB is per the math above, it is physically impossible for them to come anywhere close to their claimed specs in lumen output. Beam angle is going to be more or less subjective, but with that optic design, 160* with an even spread is not possible either. They may hit 160* with the fringe, but because LED's are inherently forward facing, that optic design won't allow an even 160* spread

 

[Patoux01]

Lighting technology is realistically capped at 120 lumens/w.

I am not sure cree agrees with you there though.

 

[BDSC]

So. Is L&M failing to do objective testing, or are they being honest with their specs as opposed to other manufacturers who are grossly exaggerating theirs?

Good question.

 

[Clark Fletcher]

Objectively, are we not comparing apples to oranges here? Seems like we're trying to compare a $300 light to a $1000 light.

 

[tbone1004]

I am not sure cree agrees with you there though.

I'm well aware that they broke 300lm/watt several years ago but those are not available on the market at reasonable pricing. We are about to get a "next gen" coming out here shortly that will be around 200lm/watt but they aren't widely adopted. BB is using XML's which are around 110lm/watt and if you get a really expensive bin, then 170lm/w. Nowhere close to the 210lm/w that BB is requiring if their claims were accurate and more importantly, they couldn't afford those expensive bins and sell the lights at those prices. Custom bins are horrifically expensive compared to the more common bins which are why companies like UWLD and L&M have to charge more. They each have custom bin criteria and most other manufacturers don't. Light Monkey, Dive Rite, BB, Ano, etc etc. Nothing wrong with it, I own several dive rite lights, several BB lights, and several Ano lights, but it's managing expectations. BB is simply not capable of producing any of their lights to the specs that they claim, at the price point they sell for, with todays technology.

So. Point of all of this for @Clark Fletcher's last post
The TL3100 is not a 3000 lumen light. It is a 1500 lumen light. At $320 retail, it is better compared to the Sola 1200 spot which is essentially the same price as opposed to the Sola 2500. Same with the VTL3100 at $400 vs the Sola Video 1200.

 

[Clark Fletcher]

The TL3100 is not a 3000 lumen light. It is a 1500 lumen light. At $320 retail, it is better compared to the Sola 1200 spot which is essentially the same price as opposed to the Sola 2500. Same with the VTL3100 at $400 vs the Sola Video 1200.

Would it be a more appropriate to compare the TL3100 to the Sola 1200 SF instead of the Sola 1200 S?

I ask because I was considering a Sola 2500 SF before I started looking at the TL3100 but, the price of the Sola made me rethink.

 

[tbone1004]

Would it be a more appropriate to compare the TL3100 to the Sola 1200 SF instead of the Sola 1200 S?

I ask because I was considering a Sola 2500 SF before I started looking at the TL3100 but, the price of the Sola made me rethink.

the SF is multi function so it is all about what you want to compare it to in terms of function.

Now, remember also that the BB has a replaceable battery, so you can do 2 long dives on the same day with the same light. Solas are not, so that is a limiting factor.

another option to consider is this guy. 2200 lumen is about right for it, has an even burn over time from what we have seen, uses a 3x18650 pack instead of 32650 *not a preferred battery size for me* and/or a non-replaceable pack and has a charging dock. Can swap the packs out easily enough if you have a second pack. Price is comparable to the others, though is physically quite a bit larger than the Solas.
HL2200 Tech Dive Light – ANO Online Shop

 

[BDSC]

You can't build an inexpensive lumen tester. You can't. Don't care how good of an engineer you are, you just can't do it. They look like the picture below, and are very big, very expensive, and very uncommon.

Depends on what you consider expensive or inexpensive. You can buy a top of the line lumen tester like you pictured for around $17,000. To me that is expensive but you don't have to spend six figures, which if that is what L&M spent, they either have a very old system they bought new at the time or they were taken for a ride.

 

[tbone1004]

Depends on what you consider expensive or inexpensive. You can buy a top of the line lumen tester like you pictured for around $17,000. To me that is expensive but you don't have to spend six figures, which if that is what L&M spent, they either have a very old system they bought new at the time or they were taken for a ride.

didn't know they'd come down that much, good to know. still relatively uncommon in the industry though as the exact numbers aren't really required. You know close enough values based on expected efficiency and actual consumption. Those are just nice to get a scientifically accurate beam pattern picture with intensity mapping. Really important for top of the line video lights, basically useless for everyone else.