UF-1504, 1503, 1505 - multiple LED's tested for throw (just what you have been waiting for!!!)

n10sivern,

Thank you for taking the time to do all this testing. I was sort of waiting to see everyone’s results before ordering any components. The numbers for the XM-L2 are impressive. Would you say it has a more usable beam than the XP-G2? I was originally going to go with the XP-G2, but 400 kcd on the XML is fine in my book.

It’s bigger. I didn’t actually do any beam shots with these except for the lux meter.

I thought maybe I should point you guys to something that can explain goofy lux results. Color temperature alone can fool a meter one way or another. With those cheaper lux meters, you’re really only making a comparison well when you have two tints exactly the same. Even when you do, that’s not saying the result is nearly accurate to what a lux value is. LEDs are one of the most difficult sources of light to properly read and measure in lux. Because of LEDs varying spectral emissions, and the sensor having points where it cannot detect all wavelengths, when a 1-sensor meter is used be wary of results. If a 1-sensor meter is used, it needs to be calibrated using a filter that helps the meter achieve a reading within the photopic vision spectrum curve of humans. If it is just a cheap meter, it will look exactly the same, but it will not have the proper filters inside to read LED light well and emulate the photopic curve. As you may recall, photopic means vision during bright, or daylight conditions. The CIE 1931 standard is based on the photopic curve. Scotopic is the vision used at night. Mesopic vision is basically using both those visions combined, in dim situations.

That basically explains what type of curve lux meters should be sensitized for—something that’s not so simple to test with 1 sensor. What the meters are actually picking up and reading may somewhat shock you. Some say, to calibrate a meter with a 60W incandescent because the value is known. Unfortunately, I found out that it cannot be done like that. An incandescent light, using heat to release light via black body radiation, has an extremely broad and solid spectral curve spanning from blue and going well into the IR region. An LED has typically only 2 peaks in its spectral signature (1 near 450nm and one in the 540-580nm area). The two light sources are very far apart in color spectra.

This article I found explains a pretty good reason for large variance with the 3 types of lux meters (cheap single sensor/calibrated-filtered single sensor/multi-sensor): OliNo » Blog Archive » Measuring Illuminance Correctly

Now I just have to buy a multi-sensor unit. J)

Luminosity function from wiki, black is photopic (day) vision, green is scotopic (night):

I did some tests on luxmeters that I posted here on BLF last year. The tests were all within my limited hobby possibilities at home, but perhaps nice to read too? The conclusions were quite like the tests in your link.

Your test is the reason I own the CT1330B.

n10sivern

So I put an S4 2B in a 1405 with a 5 amp driver, dedomed, with a collar and measured 470kcd. I’m confident now that the difference between our numbers is due to the meters. I’m willing to put together a light with a battery and charger and pass it along to a few select members so we can get some baseline numbers so we can compare our results accurately. I have a 1504 with an XP-G2 and no collar that would be a good candidate.

Each person would be responsible for shipping it on to the next.

I have been thinking about this idea of yours KKW, and what if we would take it to the next level :wink:

What if BLF had a light with a CW, NW & WW led in different pills for example a 1504, and we all sent it around to calibrate our lightmeters. Then we should be able to devise a BLF lux & basically be able to use very cheap meters but calibrated to the official BLF conversion factor, that is this light.
Someone could even sell “pre calibrated” already checked conversion factor lightmeters.

I am not sure how the maths would work, but i think it should be possible.

It’s been talked about before, I think the problem is usually too much interest. I like the idea of multiple pills.

I’d probably limit it to about 6 people with a goal of about a month. I hope n10sivern is interested, and I’d like djozz to be in on it, but shipping to Amsterdam might be cost and time prohibitive. I think anyone with multiple meters and a history of doing testing here would be my first choice for candidates beyond that.

I’ll start a new thread to organize this.

I’m game. Just need time to build things and for some LED’s to arrive. I have 2 meters to test.

Interesting, i think the difference between photopic & scotopic is a big reason why, CW light looks more impressive than a NW or WW led, when dedomed & when playing with throwers outside in the dark.

On flooders & throwers i LIKE the look of a nice NW tint the most, BUT in throwers the more CW led i use the stronger it looks somehow even when it is a a similar amp, i had attributed this to thinner phosphors letting out a tiny bit of extra light, but it is most likely very much the difference between photopic & scotopic vision response & that’s why the colder light FEELS more intense.
And i can’t imagine wanting to build a triple or quad with CW leds, that wall of 3000-4500 lumens blue harsh light :Sp urgh……but a nice 3D NW in the same lumens range is just so nice :heart_eyes:

So i have noticed that i chose colder led’s more & more in my thrower build because they feels more (and because i hope to play with RA’s soon), even though i don’t really like CW tints because they are harsh.

But then when dedomed you lose the worst of the blueness of the CW tints, it is going to be interesting to see if i like the XP-L HI 1A already dedomed CW or if that is just to much of a good (intense) thing :wink:

I have ordered stuff for a similar idea: I will make 6 constant output flashlights (with 2x7135 drivers) that are small zoomies with about 25kcd throw. I will thoroughly measure output with my integrating sphere and throw with my top quality luxmeter, and then sell them for cost price to BLF members who do light measurements and are interested. The costs are 12 dollars for the light plus shipping (=a few dollars).

This way, even if my numbers are not trusted (my 'djozz-lumen' is probably close but still has no absolute calibration, my class A luxmeter is top quality but last officially calibrated in 2008), there are six lights around with the same calibration.

Do you have any idea if calibrating with a lower output light like that would be better, worse, or no different than calibrating with a higher output light? I’m not familiar enough with the specifics of how they measure to know if they’re going to be the same percentage off through their whole measurement range. I don’t measure many 25kcd lights, but I measure a lot at 100-500kcd.

Sure it is not ideal, but in my limited experience with the luxmeters I own, lineairity was very good, also with cheap chinese ones, so I think that you get away fine with calibrating with a lower output light

I make lower output reference lights because it is much easier to get the output very constant (less problems with heat sag and varying battery sag). It is way cheaper too, the host is cheaper and because of the small size I can send it as a 'letter box' package, which is 3 dollar worldwide instead of 12+.

Here’s a poor picture of the above mentioned 1405 hitting some low cloud cover. This thing is awesome. I’m going to try the lens I have with a shorter focal length and see if the throw changes at all, I’m hoping it doesn’t go down, I can’t remember what effect it had on the one it’s on now.

Nice work. There shouldn't be a significant vF difference between different XP-L bins, but there is a difference between production batches, and I wouldn't be surprised to see the vF go up and them become more fragile like the XM-L2s have.

I always struggle with requests to publish throw and lumen numbers, because I know that my meters are not accurate. They are a good comparison tool, but if someone "took me to court" to verify the accuracy of the numbers, there is no way they would hold up. I use them far more to compare with my own stuff (e.g. before and after mod. measurements), but I don't trust them at all to compare against others results. I know some guys who have the same or similar built lights who measure significantly higher than I do and others that measure significantly lower.

Just my 2c, but I don't get too caught up in comparing with others because must of us have level measuring equipment and use inconsistent measuring methodologies. It's fun to compare, but I don't get too wound up with the inconsistencies. The only way to get comparable numbers would be to measure the lights back-to-back, same day, same place, same meter. I'm not saying that the different data points from everyone aren't valuable--because they are, but don't get too hung up on expecting your measurements to be identical to others' measurements.

Nice beamshot KKW :slight_smile:

I am surprised we haven’t seen more hotrodded 1405/1504 beamshots, they look great when maxed out, especially when there is lots of moisture in the air like all throwers :wink:

I'm out camping right now, but did not bring the 1405. I did bring the shortened 1406 and will do a beamshot tonight :-)

How nice to be out camping :slight_smile: and i see you guys in Holland have gotten summer already, here in Sweden it is still ways off and it is almost June :frowning:

19degC and sunny all day, group camping with a couple of families, drinking coffe and beer and bbq+camp fire at night :bigsmile:

A bit blurry but here's a bbq-beamshot with the 1406-shorty :-) :

https://farm6.staticflickr.com/5344/17866863200_55e2ba4015_b.jpg

(sorry, can't get the photo into the editor on my phone)