HDS Systems #23

WarriorOfLight

Flashlight Enthusiast
Joined
Oct 17, 2009
Messages
1,753
Location
In the middle of Europe
About calibration - I have an NB45 and an SDR50. At setting "1", the SDR50 is noticeably brighter than the NB40 at "1". If you get a chance, would you (Hogo) explain why that is?
Guess the reason is that the Nichia is 200lm and the Samsung is 300lm. Explanation with example: One percent of $300 is also more than one percent of $200, both it is 1% but absolutely 1% of $300 is more.
 

desert.snake

Flashlight Enthusiast
Joined
May 8, 2017
Messages
2,035
Location
Eastern Europe
Guess the reason is that the Nichia is 200lm and the Samsung is 300lm. Explanation with example: One percent of $300 is also more than one percent of $200, both it is 1% but absolutely 1% of $300 is more.

The reason must be something else, there may be a difference in beam profile and lux due to different diode sizes, or a really different level, as some NLTs had a very low 1 level.

For everything should have 0.02 lm
 

wweiss

Enlightened
Joined
Feb 3, 2017
Messages
702
Location
Weston, CT
The reason must be something else, there may be a difference in beam profile and lux due to different diode sizes, or a really different level, as some NLTs had a very low 1 level.

For everything should have 0.02 lm



This was my thought exactly. .02 is .02 regardless of the size of the LED how it's mounted or anything else. Otherwise there would be a different chart for each LED.
 

desert.snake

Flashlight Enthusiast
Joined
May 8, 2017
Messages
2,035
Location
Eastern Europe
This was my thought exactly. .02 is .02 regardless of the size of the LED how it's mounted or anything else. Otherwise there would be a different chart for each LED.

Well, I had it like this, when I compared 140 lm with Nichia and 250 lm with XPG2 at 0.02 lm, Nichia looked a little brighter, but it had a smaller radiation area, a more focused beam. Just as when compared to 325 lm XPL, it looked like 0.02 lm less brighter due to larger emitter size.
 

LuxTacGear

Newly Enlightened
Joined
Feb 3, 2019
Messages
112
I think it has to do with efficiency and the way our eyes perceive brightness. Yes they may be calibrated at 0.2 lumen, but others have more lux than the other and 300 lumen will be more efficient at 0.2 than a 200 lumen light.
 

wweiss

Enlightened
Joined
Feb 3, 2017
Messages
702
Location
Weston, CT
I think it has to do with efficiency and the way our eyes perceive brightness. Yes they may be calibrated at 0.2 lumen, but others have more lux than the other and 300 lumen will be more efficient at 0.2 than a 200 lumen light.

That is very interesting. Sounds plausible to me.
 

Hogokansatsukan

Flashlight Enthusiast
Joined
Aug 14, 2006
Messages
5,241
Location
Tucson
Well... I was out cutting and splitting wood all day. The answers are all correct (except the calibrated at the same time I screwed up the first NLT's and gave them a lower low).
Beam profile, hot spot, and tint all make it appear differently. The higher the tint, the brighter it "appears" to the human eye. A lot of "light sensors" work the same way as they are calibrated (not all mind you... the really pricey ones account for this) for a specific kelvin temp. When I calibrate each light, I have to tell the calibrator not only the output, but also what exact emitter it is to take all this into account. Henry built and programmed the calibrator, so every time we get a new emitter, Henry has to add a program to the calibrator to account for the emitters specifications.
 

wweiss

Enlightened
Joined
Feb 3, 2017
Messages
702
Location
Weston, CT
Well... I was out cutting and splitting wood all day. The answers are all correct (except the calibrated at the same time I screwed up the first NLT's and gave them a lower low).
Beam profile, hot spot, and tint all make it appear differently. The higher the tint, the brighter it "appears" to the human eye. A lot of "light sensors" work the same way as they are calibrated (not all mind you... the really pricey ones account for this) for a specific kelvin temp. When I calibrate each light, I have to tell the calibrator not only the output, but also what exact emitter it is to take all this into account. Henry built and programmed the calibrator, so every time we get a new emitter, Henry has to add a program to the calibrator to account for the emitters specifications.

Thanks for your answer. Clears up what seemed to be an anomaly in the way I judged the brightness.
 

wweiss

Enlightened
Joined
Feb 3, 2017
Messages
702
Location
Weston, CT
By the way, the SDR 50 is my favorite for woods walking as it has the throw and spill ratio that near perfect for me.
 

LuxTacGear

Newly Enlightened
Joined
Feb 3, 2019
Messages
112
I can't wait for my SDR50 18650. It should still arrive this year after christmas. I look forward to testing and see how the beam profile and brightness turns out. Never had a 300 lumen HDS, max was always either Nichia 200 or SS40 225.
 

Hogokansatsukan

Flashlight Enthusiast
Joined
Aug 14, 2006
Messages
5,241
Location
Tucson
I asked Henry about this directly. He said no. Although perhaps his technique is to underpromise and over deliver.

I haven't done it when calibrating... not knowingly at any rate but I'm old and do dumb things. The calibrator will flash all kinds of warnings if an emitter doesn't make the specified output. The only reason for a light going out with a higher lumen rating is if it was for a warranty issue where the old emitter is no longer available, and a current emitter is "dropped down" in lumens (greatly increasing runtime). This is very rare. I can count on one hand how many times this has happened since being at HDS. If something was originally calibrated at 120, it won't make 140 with the programing and calibration set up the way it is. Alarms go off. Red lights start flashing. "Danger Will Robinson! Danger!" starts sounding over a loudspeaker... quickly followed by me getting slapped in the back of the head by Henry.
 

the.Mtn.Man

Flashlight Enthusiast
Joined
Oct 3, 2008
Messages
2,516
I mean, it's not like anybody would be able to tell the difference between 120 lumens and 140 lumens anyway. I'm not even sure you could spot it in a side-by-side comparison all other things being equal, unless your peepers are exceptionally good.
 
Top