Choosing a DIR-compatible light, probably canister, tight beam, mostly for PNW diving

[MikeRD03]

Reading your text around these pictures leaves me with even more questions. In example 1&2 you are showing an ideal light beam that simply do not exist. Both common uses optic types - plastic optics and reflectors - are NOT ideal. Both have a hotspot AND spill, only the light distribution of the spill is different. Plastic optics have a more narrow spill and are more diffuse. Reflectors directs somewhat less light into the middle, but have a much better overall efficiency. So, with the same LED and the same space for focusing both types delivers about the same maximum brightness in terms of lux.

 

[lucca brassi]

Hey Bobby, I don't doubt your Luxmeter is showing this number, but I think you're measuring it an odd way. ;-)
And I am wondering why you're measuring lux "in a box"? I do it in a wide room in order to reduce false metering from reflections.

+1

If you want to operate with lumens , lux , or whatever , on the net exist prescribed accurate procedures to do that measurment .

You could do your own procedures but you have to describe detailed procedures ( in case that you have some special advantage on your product in opposite with your competition that case you also have to take into account the existing standards ) They also (competition ) may repeat your tests with their products.

Point of standards in measuring is that all do the same procedures and get comparable results . At the moment is more fashion trend on web sites manufacturers including Halcyon IMO.

 

[MikeRD03]

on the net exist prescribed accurate procedures to do that measurment.

That's absolutly correct, lucca. And when I am talking about diving light test I already published my own test conditions on my web site tauchfunzel.de. You find them here: Unbenanntes Dokument (sorry, German only, so Google translator is your friend )

And I would not have shouted so loud, if I were not knewing the optics Bobby is using in his light. The 35mm LEDIL cute-3-ss optics have a 9,5 degree FWHM, which means HALF angle. So full angle here is around 20 degree and not the promised 8,2 degree. See datasheet here: http://www.ledil.com/datasheets/DataSheet_Cute-3-XM.pdf
A quick check in the lumen/lux calculator tells me expected max brightness is 28.000 lux - and not 110.000 (!)

But this is only one example. In case ratings are presented light manufactures should deliver comparable measurements and do not try to confuse divers with false or not comparable numbers. This is simply not fair.
And there are other good examples out there for something going wrong. Best I've seen so far are the technical data from UTD equipment. Their VIZ35 light should have 3500 Lumen with 10W power consumption - a simple calculation tells me their LED have 350 Lumen per Watt. This is 30 Lumen / Watt beyond the theoretical Maximum for white light conversion (320 Lumen/watt).
Best LED driven hard are around 120 Lumen/Watt nowadays and this only without the losses of light system and front glas (-30%-60%)

 

[kr2y5]

I'm really grateful for all the pointers in this thread, a lot of great information to digest. On the other hand, I have to say, I feel a little bit disappointed about the way Bobby has been chased out of the discussion. Mike, since there is hardly anyone else left in the thread, would you mind offering me some concrete recommendations, accompanied by credible measurements?

 

[TSandM]

Somebody in LAUE is selling a 24W Salvo HID with a 9.5 ah battery good for more than 4 hours of burn time for $500. That's a steal. That light will more than suffice for Puget Sound diving.

 

[MikeRD03]

Best you can do is to check the technical data yourself. And this is possible, since most power ratings are correct. So if you don't have the Watt consumption, just multiply the voltage with the current (V * A = W) and you have a base for calculations. (12V * 2A = 24W)
With the Watt (power) rating and the knowledge that modern light are around 120 Watt / Lumen you have the real Lumen output without losses. For example a 30W light has 30 * 120 = 3600 Lumen minus 30-60% for optical losses. So real Lumen in the water would be between 1440 and 2500 Lumen.
With this numbers you can easily check the promises of the manufactures, so you see yourself who is lying and who is measuring. ;-)

Mike

 

[Bobby]

I'll say it yet one more time though, for some, it seems to be discounted and ignored. The best way to compare potential lights is to take them in the water & see them side by side for yourself. We made a comparison video for those that don't have access to different lights themselves. I'm quite sure that some will say that our video is biased as well though we made every effort to have a level playing field. I made an effort in good faith to have a civil conversation. It is clear that there are those that simply would prefer to bash and knit pick.

There are a lot of inaccurate and wrong assumptions. We don't use standard off the shelf components, a lot of what we use is made specifically for us and our lights. When talking about efficiency I guess that all manufacturers ie; the LED, optic, & luminaire manufacturers have it all wrong. We as a luminaire manufacturer do rely on accurate information from our vendors. We use their engineering calculators instead of marketing technical data sheets to ensure that we have accurate numbers. Which if it is the case that no one, except the few in this thread, know what they are talking about it brings us back to my first statement. Take the lights in the water and do a side by side comparison. When talking optical efficiency this might help the others that are viewing this thread to get a better understanding on that subject. This document is rather general however also rather simple to understand.

I made my efforts to clarify and it seems that it only results in attacks. We, as well as other manufacturers, make every effort to be accurate and help with understanding. There are manufacturers that make wild claims & use inaccurate numbers however not all or us. In the past others have brought to my attention that I get too technical & make things confusing. Now when I attempt to present things in a simpler way I'm being misleading. We will continue striving to make the best dive light there is and to be accurate with their performance. This thread has already taken enough of my time & has been well derailed as well.

Go out and dive the lights side by side to determine what you like best. Consider the bang for the buck because spending less money up front is not always the best (& most often not the best) option. Get a light that fits your type of diving and that you will be happy with. Having the most light output or the most expensive light is a lot of over kill if you're diving shallow reefs.

BTW we have many divers in the PNW using our lights, have switched to them from HID, & are very happy with them.

 

[MikeRD03]

Well, I don't think anybody was attacked, cause presenting facts for a doubt should be allowed in a public forum - and I was not alone with this doubt.
A good answer would have been to prove me wrong instead of been affronted by a profund critic. ;-)