(prototype) the GT Mini

I’m guessing the 0.09290304 number is about converting feet to meters. Candela is always meters.

By far the easiest way to measure it is try to find 10 meters in your house. It doesn’t need to be completely dark or anything. Just subtract whatever the ambient light is from your total reading. I typically set my light down so that the emitter (not lens) is at the 10 meter mark from the sensor (meaning 1” from the wall). Then I turn on the light and walk over to the opposite wall and try to find the area of the hotspot that is brightest (I measure along a straight line between the center and the edge of hot spot). It can sometimes take 25 or 30 seconds, so I just kind of count that out in my head. Once you have the number at 10 meters the math becomes very easy. You take whatever that number is and multiply by 100 which is just adding two zeros to the end.

So my GT Mini was 1,480 lux. This is 148,000 candela at 1 meter. Easy math. My big GT was 10,560 @10m which is 1,056,000 cd. 10 meters is the way to go if you have the space.

Then to convert to distance is the regular X4 then square root.

Mine thrunite v6 measurement are similiar to nkresho. If that is true, mini gt cw have more lumen than nw … i was told mini gt cw led are high bin. anyone can verify ?

Here’s my formula reference:

Lux to candela calculation with distance in feet
The luminous intensity Iv in candela (cd) is equal to 0.09290304 times the illuminance Ev in lux (lx),
times the square distance from the light source d2 in square feet (ft2):
Iv(cd) = 0.09290304 × Ev(lx) × (d(ft))2

Source is here: Lux to candela (cd) conversion calculator

Sorry, hosted to imgur, since photobucket and imageshack are garbage nowadays.

My sphere is a semi-copy of the “match sphere” Started with a ~17” bouncy ball, paper mache’d it ovfer and over for a few weeks, then did a few layers of fiberglass for strength. Cut it open, sanded the inside and painted it with BaSO4. Two baffles using pingpong balls, also BaSO4 coated, were added. One to catch direct light between the source and the sensor, and a second to catch the primary reflection directly opposed to the source. It uses an interchangeable light plate similar to the newer TA tube design, so each plate can be the right size for the light and I can swap them easily. They are also BaSO4 coated. Sphere is also calibrated with Maukka lights and have a variable multiplier correlated to color temp. Warmer lights get a slightly lower multi, due to how my DrMeter reads.

I think you are making your calculations way more complicated than necessary. I would just use a simpler method such as 10 meters. There’s no need to reinvent the wheel.

It’s all in a spreadsheet. I just plug in the lux reading and it does it by itself.

I work in excel all day long at work. It’s only complicated once.

But, if it’s not accurate (the math involved), I am happy to change it up.

Very nice unit. :+1:

Thanks. She’s kinda ugly, but does the job well as far as I am concerned. Lumpy like a big black meatball on the outside. Was so sick of paper mache-ing that I didn’t really sand the outside to a body shop quality finish like I originally planned. Business end (inside) is baby-butt smooth.

I can’t understand what your saying here. Are you saying that the Mini GT cool white has more lumen than the Mini GT neutral white?
Where does the Catapult V6 fit in?

Jason, I think he’s saying that he gets similar readings as nkresho on the Catapult as a reference to accuracy, then says his mini gt with cw has more lumens than the nw which it should. Given the same power bin a warmer tint will always read lower output.

Nice work nkresho, the complication is that you are using feet instead of simply staying with meters as per the industry standard. Aside from that the calculations are the same. I really don’t see any need to convert with that 0.09 number, as distance is distance regardless what you call it. But then, what do I know? (no answer required, I get it…)

<— zip experience with spreadsheets and/or excel. :wink:

Yes … I measured my v6 with shockli.

thrunite catapult v6. 2050 @ turn on. 1970 @ 30 sec
Blf gt mini 1390 @ turn on. 1300 @ 30 seconds.

received mine (from the group buy) today!

something to fiddle with when it gets dark…

is your gt cw or?

I don’t know who posted this to make tail cap measurements one handed.

So I’m probably going to be the last person from the pre-sale to receive their light……

Had an ETA of Monday the 27th, and then when Monday came and went, it suddenly changed to stuck in customs. And all of that after the 3 week delay in China.

Well that blows…sorry man…hope it comes soon.

Does anybody elses make a ticking sound?

I have not noticed it on mine.
.
.
@Delta_V…… Darn… you have had worse luck of any of us it seems. :person_facepalming:
Hopefully it will get there soon.

Hmmmm…prob cant hear it outside…but it sometimes does it…then like 3 sec later drops output from turbo.

Yes it is cw.