# Luminous flux comparison



## haloweenhamster (Jan 12, 2008)

hi iv been looking for LEDs to use on a car for spotlights and iv found 
20w LED luminous flux - 1100lm
50w LED luminous flux - 3500lm

they both sound bright but I want to know how they compare to Incandescent, halogen, Fluorescent and street lights(sodium i think)

ps ill be using a 15º lens

Thanx HH


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## VidPro (Jan 12, 2008)

cool tesla pics.

there are more than one of these 20W things. i got the DX ones.
I get more light, with less than 1/2 the total power of halogen Candleabras. but you know candlabras arent nessisarily wondefull.

It comes close to the output of florescent, but because its AIMED, it does good. hard to compare when a florescent usually has some light going where it is unused, or wasted, these things are 170* not 360*. on the other hand its very floody for a led, not 60-90* output like domed things. that might make more light hit a reflector, and become spot instead of spill.

It is hard to compare to a street light, because they are WAY up there , but all our sodium vapor street lights are Barf, the color is Auful. without any spectrum how would one compare? the bluish white from the leds would be percieved to be brighter. but for meter readings sodium vapor is very efficient, its just more spectrum deficient than leds even.
how about compare to mercury vapor  , i think mercury vapor would blow it away in percieved visuals.

The large arroys will not be anywhere near efficent as the Cree run at 350ma, but then again a cree doesnt have 100lm/w at high drive currents, only at lower currents, If somone could afford it and it fit the package 15 crees run at 350ma (15w) , would be very efficient and long running.

i am running 10X20W units, and they are very sloppy in the precision of the series parellel emitters in the array , each triggers at different voltages, so i dont run it at full power, i dont think it will last really long at full power.
then of course that is a lot of heat to dispel.

if my CITY asked to use my tax money to run these as street light like 100W of them to replace that huge sodium vapor thing, i would tell them to WAIT, till they improve the Precision of the emitters in the array. i would tell them to have some way to Socket the item for replacement, and to drive it at currents that the heat was not as much an issue. and wait till the price of things like this went down, or the quality went up.

if i was making a flashlight, and output in a SINGLE item was important  well time to blow away hotwires.

You have to pull ~18 and ~46 watts of heat off the things somehow. figuring that to a computer processor, my AMD is some 65Watts of heat to remove, and if the fan stops , so to does the processor it croaks permentally. so when run at FULL bore, they are going to have to have good concideration for heat removal. that is why i choose to run at 1/2 and therefore also more efficient.


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## haloweenhamster (Jan 13, 2008)

cheers for the reply
I knew it would be hard to compare I just wanted to know if the 20/50w LEDs would be any good as spotlights for a car and try to compare them mainly to halogen equivalent
there seems to be only luminous flux information for LEDs and luminous intensity for all other forms of light source

I was trying to use just 1 emitter per side because if you've seen mr16 or gu10 led replacement bulbs the multi led ones don't look very good but the single emitter ones look cool(I know the the single ones aren't really single there multi emitters in a single package but it gives the impression of a single emitter)

the LEDs will be going in the front of my car so with a 100x100x50mm heat sink with probably 60MPH air cooling I think cooling wont be to much of a problem for short term use anyway as I don't think an MOTer/COPs will like the idea of home made lights being used on public roads especially narrow beam high intensity ones so they are going to be for offroading

any other ideas will be usefull altho this thread is for light level comparison so I might start a new thead for that one

Thanx HH


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## VidPro (Jan 13, 2008)

ohh, whats a luminous flux 
i have been Lied to so many times about how bright anything is , i have simply given up on any of that manufactures or sellers claims. I use the Data provided by the users here in this forum, who have light meters, and only cross compare against that same user.
Ya know them people (sellers) told me that leds were 10TIMEs as bright for the same power as an Incan when all this started, and they were at some 40lm per watt or less.
when i finished projects it was more like it took 1/2 the power to do the same thing, and the loss of spectrum outdoors was pretty bad.
now things have brightened up , but the claims still are a bit high, then over TIME the cheap junk got darker.

people would buy stuff, and say Oh My that is soo bright, use it for a while and it got dimmer, and the next thing they would buy was bright again (new), ohh they really did make it better  ya right. lots of stuff (specially 5mm leds) was just failing over time.

all that stuff is why i started ignoring wizz bang spec junk , and tried to find stuff that runs nice and bright, AND will do so for a long time. the lux3, the cree, and the seoul leds do that, the seoul EMITTER item has issues with heat sinking due to base isolations, so i avoid it. there are certain things done to the great leds, that addresses the heat and time issues. leds that can overdrive high, often are the same ones that when driven normal survive time.

cheap 5mm leds are great at first, but after hundreds of hours they arent worth powering up, i had applied hundreds of them, they look and act a whole lot like the 20W led, same "china white" (bluish), same offset voltages of gates.

you saw this right https://www.candlepowerforums.com/threads/186184
i have had these led for a long time, and did some very rough tests.

i know exactally what you mean (as probably everyone else) about needing a SINGLE small source of light, to try and get reflections or lensing without computer controled laser cut reflections, for multiple items, and crasy stuff like that.
re-aiming 20 little lights, or having huge reflectored arrays . to many parts and pieces to maintanance or have impact damage or fall apart, simpler the better.
nobody wants xmas tree lights with the little items for normal lighting.
but
whenever possible using the cree or seul in multiples would be better, we can do it for flashlights, It could be in headlight already too?? 7-9-12-15 leds in a flashlight, its been done by some nut here 
but its Easiest, and least parts and pieces and one shot to use one huge item. and for that the 20W worked great, but i am not sure i would use it again.

say 5 cree white leds, and a center red one, driven at full 3W , mount it on a alum heatsync and run the latest Optics not reflectors because they haves so much spill, there is a awesome optic for the cree that sells for little.
that would walk all over anything i could do with the 20W. the red one is for putting the red back, but on AUTOs it would probably be illegal even if its just a blender to the spectrum :-(.
You have seen the awesome overpriced Bike lights they make around here with cree, like billet parts for a harley, 9W of cree power , and a very nice package.

Ok you are going to have 15* with a 50W, the first thing i shoulda asked is HOW?


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## haloweenhamster (Jan 13, 2008)

ok iv only seen a 15º lens for a 20w led, I haven't seen any drivers/lenses for 50w LEDs yet

I mainly want range as full beam doesn't go far enough for me and fog lights are only short range hence the narrower the better

blueish white is ok I'm from the UK we like cool white so I wont need a red led to change the spectrum to make it look more yellow/orange

the more illegal the better as its going to be for offroading so as bright and as much range as possible is my aim, i want 2 of the 20th century fox lights on the front of my car

efficiency is no object I have a 80Ah battery and the engine will always be running when the lights are on, no eco friendly greenness here this global warming is as real as the coming of the ice age in the 70s 

to make the beam as narrow as possible and for look purposes I would like the light source to be as small as possible ie single source or as small a cluster as possible

thanx HH


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## VidPro (Jan 13, 2008)

you do know about HID offroad lights with huge reflectors?
if you dont mind Blue , HID in the higher wattages is 3X more efficient as incadescent (not sure about halogen in those claims)
like a 35W hid will indeed put out what looks like 100W of light, it has the caveats of takes a bit of time to warm up (10 sec) they often seem to be bluish like leds, even though they sell warmer ones too. and the Life of the bulb is about 2X the average headlights.

trailtech was selling some 24W ones for a pittiance that would make good driving lights.
http://www.trailtech.net/4211-SX.html these could hang low wiithout destroying clearance
or
the new baddies http://www.trailtech.net/4412-DX-V.html these are biguns
(they have a good price see) thier other stuff came in a 6* spot or a 13* wide.

(oops LED forum, must stay on topic 

how does that compare to the price of this http://www.dealextreme.com/details.dx/sku.5766
which will put out about the same, light Instantally, and not break under extreeme conditions, and should last at least as long.

what optic do you have for the 20W that does 15*? and is it 15* duel asmith or 15 total?


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## VidPro (Jan 13, 2008)

driver for the 50W 2.5amps at 18V, dang to bad they didnt series it up to 14v instead of having 5 leds in series.

a driver for the 20 would be easier , because its only 1amp, and there are choices in high voltage series led drivers that get to 1.2A or 1.4Amps max.


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## haloweenhamster (Jan 13, 2008)

to be honest I'm more electronics and audio then light so I don't know much about lenses all that I know is that it was like a bowl shape with a point with the top chopped off in the center
(sorry ebay imgs so will probably disappear in 90 days hence description for future proof)









its probably not very good probably as good a quality as the LEDs iv order but they might be used for another project anyway but they didn't cost that that much so worth a play

perhaps i should look into white laser diodes and fog machines get the same range with 5mw as a 100w led(if they ever make them the 100w led that is)


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## haloweenhamster (Jan 13, 2008)

the 50w led iv seen here
50W Cool-white LED with Star 3500LM from Taiwan Edison
LED specification:
(1) Average 3500LM
(2) Input current: 2.4A
(3) Input voltage: 23V
(4) Led life: up 50000hrs
(5) Save power more than 5 times with traditional lighter
(6) Reaction time: 100ns

7s x 7p 49 emitters

i know thats only 100mA difference but it makes 4v difference according to the spec anyway

and it was good to see a 20w led compared to other LEDs with different lenses cheers for the comparison

hid are boring ever chav has them with blue washer LEDs and led clusters for the rear lights and drive around with only there fog lights on

I want something new futuristic before everyone else does it


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## VidPro (Jan 13, 2008)

ohhh now i see, that says it kicks lumens out much better, it says the 50W is 70 lumens per watt.
and the 20W is 50LM per watt.
and they are selling a boost driver with it too. that was nice of them

that is completly different than that other thing.
http://www.dealextreme.com/details.dx/sku.5848 see here is the 20w i got.


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## VidPro (Jan 13, 2008)

ok
a long term 100W halogen bulb for home use, but watts is watts is clamed to be 1275 Lumens 
normal 100W 1750
a 100 watt bi-pin with much shorter life 2900
a standard soft 60W bulb can do about 850 lumens
a small 20W halogen bi-pin 350 lumens

a very good tube florescent 35W has 3000 lumens
50w Industrial CFL 3,870 lumens 
a cheap CFL bulb 23watts claims 1600LM
20 watt CFL 1200lm

30W HID claims 3200 lm
50W Hid contained claims 4500

a Cree at 3W drive does about 200lumens
at 1W about 100 lumens
5 Crees at 3W drive 15W total 1000lumens
10 Crees at 1W drive 10W total 1000lumens

50W sodium vapor 4000
100W sodium vapor 9000
200 Watt Sodium Vapor, 22,000 lumens 
400 Watt Sodium Vapor, 50,000 lumens

1000w Mercury vapor hid , Initial Lumens 57000, Mean Lumens 28500
(now isnt that par for all this stuff, which are you gonna list)

for bulbs in containers, like a 100W outdoor relflector halogen from 500-900lumens.
huge losses in how its contained reflected and diffused, and if the bulb will last TIME.
the specs to COMPARE with , would be raw bulb lumens, cause that is what you have a Raw bulb item.


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## haloweenhamster (Jan 13, 2008)

i did look at them but I thought that the aluminium star should in theory help with heat transfer make for better coupling
also as it has pads and tracks going to the emitter I thought it would be better then legs sticking out of the sides which knowing me would probably brake 1 off on first use
output difference of 200lm on paper as well


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## VidPro (Jan 13, 2008)

the DX things have a copper base, tinned in something.
BUT, how the heat output emitters connect TO that base , and what is in between them, only Newbie (resident led tear apart expert) would know 
the things that seperate the heat from the heat removal, have been studies here a lot, and from what i have seen any thermal reductions at any seen or unseen aspect of it, can change the "die" temperature of the led by 5-12* celcius.

the legs sticking out are very durable, but they also move heat out, so i left them sticking out.


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## haloweenhamster (Jan 13, 2008)

cheers VidPro thats exactly what I wanted I just couldn't find that info on google hope I didn't wast to much of your time

when I get the 20w LEDs ill have to take them to work as they have a calibrated LUX meter although it does not tell you the luminous flux rating so I cant compare it to the spec but I can give you a hint on what the Illuminance is like if that helps at all

I could of got the same amound of light off of 5 3w leds but hay I wanted a small package and it will probably seam brighter as it should be more focused

so I might see which is easier focusing a 30w HID or focusing a 50w led and building a 2.4A constant current supply(or run my PSU in my car off a inverter)

cheers again HH


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## VidPro (Jan 13, 2008)

What about optics?
so you have not yet tested the Optic, on the 20W emitter.
Cause, when i did that optic test on the FLAT emitter using the frogeye type optics, its no so great, way to wide for driving type lights.

here is a point, with most optics on the Domed emitter things, the actual light emitter sits above, and INTO the hole in the bottom of the optics.
The dome lens on the domed leds, really shoves the light into the optic.

these flat things, even like lo-moons and rgb leds where the optic doesnt drop right OVER the led, usually lose a lot more light than some far fetched 97% , which is only the transparency of the optic.

Gee why dont i just say, Optics are gonna suck on these, because its just losses of lumens from containing an pointing. 

plus i doubt that those 15* optics are going to give you driving light type of output, with the large base of these leds.

i crasily measured the headlights on my motorcycle and car, by using a protractor and a straw  (well i wasnt going to get facts about only my light) i figured headlights are around 13* total, for most of the light.

on my motorcycle i did a 5* spot and a 13* spot to get the best of both worlds.

so one issue with these large base items, is getting the light foreward, not loosing it all.

with a reflector all the side shooting light would hit the reflector and tuned right become spot, every thing else comes out as spill, and is going to mess up your vision in a blurr of flood, these have LOTS more side shooting light, that will hit a reflector.
a deep reflector could work, or a better optics DESIGNED specifically for these wide flat outputs.

that is why i tested the aspherical lens, even though it looses light in the containment.

you see i am really interested in Figuring out how to pull this off also, with all the limitations because of the design difference.


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## haloweenhamster (Jan 13, 2008)

this is all new territory for me I'm more thousands of volts sparking everywhere and kilowatts of music and testing PCBs

perhaps I need to do a bit more research thats why these forms come in useful you find where your going wrong before you go wrong

the seller where I bought my LEDs from only had 80º lenses so I didn't both with them


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## VidPro (Jan 15, 2008)

check here
https://www.candlepowerforums.com/threads/185456
because its the same type of thing as what your doing.

and in the whole light modding section, for MUCH more info.


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