Really?
lolz isnt it past your bed time chicago? i have typos when i use my iphone at work constantly watching over my shoulders you ?:?O**&O**>O?^&$% |(
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10:35 PM
Wednesday, January 9, 2013 (CST)
Time in Chicago, IL, USA 
I have no idea. My only mod so far is stacking two 7135. Are you getting SBT-70 to replace your SR90 SST90?
I bought a XML2 and 3.04A driver from int-outdoor and plan to upgrade my Ultrafire C8. Slowly I will do more modding, but only on budget lights. Buying higher end lights is to enjoy design by the brand. That is why I am willing to pay them.
There is no need to spend any money of anyone here. We just need a convincing review. I propose to do video and do it with two flashlights as below:
1.The other flashlight(maybe your TN31) will be the reference to check on meter consistency. If the meter drift upwards, it should shows that TN31 also drift upwards.
2.Since your TN31 is just for reference, so it doesn’t need to be on for the whole 10 minutes. Only measure it at the beginning, the middle, and at the end. Do this by pointing BTU downward sitting on table so that BTU doesn’t affect the measurement.
3.BTU will be switch on from start to end for 10 minutes pointing at the meter. When it drops every 3 minutes, just put it back to Turbo.
4.The video is full length 10 minutes+ with BTU in the frame so that it clearly shows actual usage without fan cooling. Hand cooling is ok as it is actual usage.
5.Ambient temperature recorded in the video either.
I am sure if this video is created and shows the best performance of BTU, BTU’s sales will be improving.
This all sounds reasonable. But again the only catch is this cannot be done indoors, has to be done outside due to the distance needed. So how do I do this while outside at night and the meter and light 15m apart?
So are you thinking the output is going to drastically drop in Kcd? I can’t see any logical reason that it would drop very much. Even if the lumens dropped say 25%, which I seriously doubt will happen, but even if it did, the light would likely still have very respectable Kcd. I would say even at its 2000 lumen high it will easily do 110Kcd. I haven’t measured it though in high vs turbo though yet, but I know lumens don’t have a huge impact on throw. So I’m not sure what your hoping to see.
But I’ll see if I can figure out a way to do the experiment.
I am considering doing a sbt-70 swap on my SR90. But I am just trying to find out more info on it. A SBT-90 swap I doubt would gain anything over my dedomed SST-90 that’s in the 195K range now.
I just don’t know how hard the SBT-70 swap is to do. Or if it would even fit. Or how much gain I would see. The bigger head on the SR90 vs the SR95SUT I would think would counter balance the claim that the SR90 is powered at 9a vs 10a on the SR95SUT. I would think anyway. So 250K should be a realistic target.
I am not familiar with lux meter. Is it your meter max can measure 50kcd, wonder why you need 15m to do the measurement.
My lux meter, just like Dales above, can measure up to 200Kcd. On average lights, EDC’s, etc, testing them at a true 1m is fine. I have a special tool I made to do just that. But when lights start getting in the thrower category, you can’t measure them so close. Lights in the 50K range and above need measured at higher distances. Those can me done at 5, 10, or 15m. Lights in the 100k range should be tested at 15m and above. Lights throwing 500k and above might need 100m to get a proper reading.
Throwers need a long distance to allow its reflector to proper converge its beam. It’s a fact. Some can do it a smaller ranges, some cannot. As an example, my SR51 which measures right at 50K can test true at 1m. Hower my brothers A60 which will do about 70k, only reads about 35K when done at 1m. But the higher the Kcd number is, the more likely the distance needs to be increased. Another example. My SR90 only measured 105K at 1m. But when measured at distances of 15m - 100m, it reads about 144k. And now that its dedomed, it only measures about 85k at 1m, but 180k at 15m, and 195k at 50m.
And of course when the distance used to test increases, you have to calculate it back down to 1m for proper comparison sakes.
Now I know these higher numbers I have been quoting are correct, because I always test all our lights in the field with the meter reading down to .2L to find their true throw. Most are very close to the Kcd readings. Wish I could do exactly .25L, but most meters only read in the tenths. So I might be off on real throw readings by 25m + or - .
Anyway, that’s my the problem - I will need at least 15m to proper test the tn31 or the BTU.
all right Fronty you won . i ordered the demn btu u2 cool white . 14 days pf waiting begins
Gotta be kidding me. Someone ACTUALLY made a sale of BTU shocker to shaquille!!!
Now that is one heck of a salesman. :bigsmile:
You have just purchased a great light Sir! But seriously, I’ll keep my word, if you are disappointed in that lights power or throw like I stated above, I’ll buy it from you. You can hold me to it.
Sure the the battery carrier could be improved with a center post and yes a AR lens would be nice, but over all its very nice light. I mean where else can you get 3000 lumens and 700m throw in a reasonable sized package?
Some other lights can match its 3000 lumens, some can match its throw, but the combo - nope.
Anyway, I’ll still try to do some testing for you if I can figure a good way to do it.
Oh, do make sure you have some quality 18650’s. It will need it with the 3.8a per battery draw for full power. Ultrafires & etc likely wont cut it.
I have a dozen panasonic 3100 s
And 2 sysmax 4 bay chargers 
lolzz . its just for testing ok . Dont you get all accited pulsar . and and besides fronty says its good then its all good ( i did drink some wine after work today so may regret this in the morning ) demn its time to shleep
I find it hard to believe lights will converge on certain distance. Light travel straight line.
The problem could be your meter linearity. It is not calibrated as linear we thought, it might be calibrated at one point(let’s say 50kcd) and extrapolated to other points. That means if you can find your meter actual calibrated point, then adjust your distance accordingly in order for the meter to measure at its sweet spot.
The A60 you mention must be something wrong in the setup or the light itself.
One very simple analysis on this throw measurement.
For throw, we are interested in hotspot as spill will not help in throw.
Any lights travel out of hotspot will not get into hotspot again. Any lights travel in same direction with hotspot will forever inside the hotspot.
That means if you have a perfect accurate meter, the closer you put your flashlight to it, the higher it will measure after conversion to 1m.
Because closer means more lights are still inside the hotspot. Further away, less light in the hotspot, you should measure it lower after conversion to 1m.
But your result shows that the further away, the higher your reading after conversion to 1m. That means your meter is not perfect meter, it is not as linear as you thought.
No, he obviously meant the lux calculated back to 1m. Seriously, you don’t expect the meter really showed 144k reading at 100m do you, because that would mean he’s doing 1.44 Gigalux @1m, and it throws 75km. :bigsmile:
Getting higher calculated reading as the range increases is understandable, as light collimation is completed. Multi emitter normally have longer collimation range.
No, that is a fact. I promise you. The stronger the thrower, the longer the distance needed to properly test the light for lux. Nothing wrong with the meter. Do some research here and on the other forum you’ll that’s how it’s done.
For an example, a test of my sr90 (dedomed) measured 78 lux at 50m. To calculate the true lux you multiply the distance towards itself, then multiply that with the measured lux. So here 50 x 50 = 2500, 2500 x 78 = 195,000. That’s how you have to do the throwers.
Now for the reverse. Mr sr90 will do 195k. To got the throw in meters from that number, you divide it by the desired lux target, .25L in our case, and the find the square root of that number. So 195,000 divided by .25 = 780,000, and the square root of 780,000 = 883m. That is how to get the ANSI rating from your Lux.
Yes, I am saying the lux after calculation back to 1m. Now we are talking about single emitter. If his meter is linear, he should get result below:
X = 2m test, lux calculate back to 1m
Y = 5m test, lux calculate back to 1m
X>Y
But now his meter shows that Y>X after calculate back to 1m.
It doesn’t make sense as at 5m, more lights get out of the hotspot. Only explanation is his meter is not linear.
I am not challenging ANSI or other so called fact.
But I think if you think your SR51 is 50kcd and the meter is measuring it correctly, then you should be able to measure your SR90 which you think is about 195k at 2m. Because at 2m, your meter should measure about 50kcd, times 4 will calculate back to about 200kcd.
I believe all these low cost meter has a sweet spot, it is not calibrated from 0.25 to 200kcd, they might not be uniquely calibrated at all but just loaded with generic calibration data.