HD vs LD

[panama]

hi..i am a new member and cant believe there are other people like me with OFD (obsessive flashlight disorder)..my friends and family think im nuts with how many types and how much money i spend on flashlights..heres my question...i just ordered an arc ls1 rev 2 from pocket led.com because i was under the belief that the luxeon high dome & low dome were basically about the same brightness but with different beam patterns. however the arc web page lists the specs for the blemished ls2 as having a 50% brighter hd led..can someone help me to understand if i made a mistake buying a ls1 rev2?

 

[B@rt]

Welcome to CPF panama,
Sorry I can't really help you with your question, but rest assured, an answer will come ...

IMHO, not having a LS, the HD has a somewhat better "throw" than the LD. Total light-output should be the same for both.

 

[hotfoot]

hi panama,

Welcome!

all else being equal, practically any luxeon-based flashlight (or mod) will have its brightness most affected by the *binning* of the white luxeon LED(s) used.

according to the luxeon datasheets, the differences in nominal output between the dimmest and brightest bins can be up to 100%! and that's not even mentioning the differences in color temperature and forward voltage!

any small-to-medium volume manufacturer using luxeons will very well know also that procuring the luxeons themselves in specified bins and qtys is a tricky affair and is very much the luck of the draw. even if you buy them by the 1000s, you can't always guaranteee that you'll be getting what you want or that you'll even be getting all of the same thing (you might end up with mixed bag of LED bin grades)!

all these factors conspire to make life a living hell for poor guys like Peter Gransee, who has to consider the possiblity of waiting for WEEKS for another shipment of parts if he rejects what he gets. and even then, he won't be able to trust what he'll be getting as replacements either!

recent batches of luxeons have been getting brigher and better in general, so its not surprising that newer revs have more oomph.
and if you examine the datasheets, you'll notice that the HDs and LDs have identical luminous flux specs. trolling the threads will also yield further proof that the LD luxeons have as much kicka$$ potential as the HDs if properly applied.

IMHO, you didn't make a mistake. The Arc LS is a fine flashlight and it was unfortunately and unevenly affected by one of the few things beyond its manufacturer's control.

 

[sunspot]

pamama is a true flashaholic. "Brighter is better".

 

[Rothrandir]

welcome to cpf! you are not alone in your dissorder!

the difference is not in the brightness coming out of the led peter is refering to.

the reason the hd appears brighter is because when used with the nx-05 optics, it concentrates the beam more than a ld which is more of a flood.

peter could have a brighter batch of hds this time, but i don't believe that is what he is refering to.

if you wanted it for close range...the rev2 is what you want.

if you wanted it for a slightly longer range, then the ls2 would be optimal.

but of course, there is always the flashaholic motto: get both!

 

[Gransee]

I think of brighter as meaning, "the spot on the wall is brighter". But brighter could also mean, "more light".

The HD parts are more focused. This makes the spot on the wall brighter and the beam to project farther.

Also, the HD parts have a new phosphor deposition process (EOS). This new process wastes less light in re-emission, therby increasing the overall efficiency of the LED. Therefore, HD parts general are more efficient, making them produce more light for the same run time.

Combine these two, and the HD tends to produce more light, produce a brighter spot and throw its beam further. With the variations in the LEDs and the new technology, a "50% brighter" is what I estimated would be the average perception from our customers.

Peter Gransee

 

[panama]

thanks for the responses...does this mean i need to buy an ls2 also!! maybe i will be able to enjoy my ls1 rev2 long enough to skip buying an ls2 and get an ls3 when they emerge:)

"..once in awhile you can get shown the LIGHT in the strangest of places if you look at it right.."

 

[Rothrandir]

of course you need to buy the ls2 also! you are a flashaholic aren't you?