Should I be disappointed, or suspicious of these modification results?

Flashlight Modding and DIY Parts
1

I am pretty new to the flashlight modding game. Tonight I built up two lights:

Convoy C8, mtnelectronics FET+1 driver, XP-L V6 3D,spring bypass driver and switch.

Brinyte B158, BLF A6 FET+1 from gearbest, XP-L HI V2 5A2, no spring bypasses.

At 5m, I measured 1520 lux for the C8, and 3200lux for the B158.

If my math is correct, that is 38kcd for the C8 and 80kcd for the B158.

Both had fresh 30Q batteries.

Should I be disappointed, especially with the B158? I was expecting double that output from it.

Or is it more likely that there is something else going on, like a measurement error? My lux meter is very cheap and I don’t have a ton of experience with it or measuring other lights to compare to so far.

Edit: Updated numbers

I am not going to post Amp readings yet, because I have not modified a meter to use short heavy gauge wire, so I believe my current current readings are not reliable.

But I did buy a new Lux meter, an HS1010A. I also checked Lux readings with my phone. Results:

At 5.04m distance:

Convoy C8, mtnelectronics FET+1 driver, XP-L V6 3D,spring bypass driver and switch.
Multimeter with built in light meter: 1520 lux (38kcd) (–26%)
HS1010A: 2050 lux (52kcd)
Phone: 2220 lux (56kcd) (+8%)

Brinyte B158, BLF A6 FET+1 from gearbest, XP-L HI V2 5A2, no spring bypasses.
Multimeter with built in light meter: 3200 lux (80kcd) (–50% !)
HS1010A: 6360 lux (162kcd)
Phone: 7100 lux (180kcd) (+12%)

Are 52kcd and 162kcd more believable for the lights with the listed mods?

2

What meter do you have? I think the HS1010 and similar meters tend to read low but I wouldn’t be very surprised if it was way off. It’s not even totally the cheapness of the meter, different meters respond differently to different parts of the spectrum depending on how they where built, this is why expensive meters have different CCF (color correction factor) settings.

3

I’m using the Lux meter built into a $35 multimeter.

4

Hard to say then unless you have something else to compare it to. Can also check your focus but in those lights that probably won’t be a huge change.

5

I personally don’t own any lux meters but I’ve tried a few different ones. Whenever I took a measurement the difference was huge between meters.
Do you have any amp readings at the tail? Assuming the focus and the overall build are spot on and that there are no technical issues; this would help understand where the mods should land from a performance point of view.

6

Yeah, that was my thought as well - without either a known value, or a second meter to compare to, I’m kind of stuck.

I’m searching BLF as we speak for potential budget friendly light meters. It looks like there’s a few good apps that would enable my phone’s light sensor to be used as a sanity check. I wouldn’t use a phone as a primary meter, but as a secondary check it’s probably a decent solution.

7

The LX1330B is a very popular meter and pretty budget friendly. People seem to get good results with it and I’ve seen tests against a lab grade reference meter where it came in only a few percent low in LED tests. Remember all these meters are probably quite accurate in “normal” lighting but LEDs have very tight and uneven wavelength bands, at least unless we are talking about very high CRI LEDs.

8

With the C8 you should expect at least 50-60kcd, your meter is probably reading low. Why not use a XP-L HI instead? It makes a amazing pocket thrower…

9

Those are realy low values m8, espcialy the B158one- i usualy get like 220k cds using dded XPl and if the emitter is good 240k
The C8 value is fairly okay, i got 38k with my V6 3D / X6 host

XP-L HI V2 5A2 - such thing does not exist, i presume its U3, not V3,yet your results are quite low

10

http://www.mtnelectronics.com/index.php?route=product/product&path=60_106&product_id=596&limit=50

Well if it doesn’t exist, mtnelectronics sold it to me anyways, lol.

11

Is this XPL HI V3-3C also wrong?
Only know V2-3A

12

v2 5a has to be tested definately! 10x for the link!
As long as it comes from Richard it should be genuine
I havent seen that bin anywere so far

V3-3C - i have V3 3C from Mouser, its even CRI80( kinda poor R9 though)

13

I second this suggestion, getting a tail amp reading would indicate if the problem lies with the lights or the multimeter.

14

Update:

I am not going to post Amp readings yet, because I have not modified a meter to use short heavy gauge wire, so I believe my current current readings are not reliable.

But I did buy a new Lux meter, an HS1010A. I also checked Lux readings with my phone. Results:

At 5.04m distance:

Convoy C8, mtnelectronics FET+1 driver, XP-L V6 3D,spring bypass driver and switch.
Multimeter with built in light meter: 1520 lux (38kcd) (–26%)
HS1010A: 2050 lux (52kcd)
Phone: 2220 lux (56kcd) (+8%)

Brinyte B158, BLF A6 FET+1 from gearbest, XP-L HI V2 5A2, no spring bypasses.
Multimeter with built in light meter: 3200 lux (80kcd) (–50% !)
HS1010A: 6360 lux (162kcd)
Phone: 7100 lux (180kcd) (+12%)

Are 52kcd and 162kcd more believable for the lights with the listed mods?

15

I have around 160 kcd with my B158 modded with an XP-L HI, my luxmeter is well calibrated and consistant with know readings by lots of other people on several lights.

16

Thank you for the data point JamesB. What are the specs of your B158 - emitter bin, driver, any spring bypasses?

17

XP-L HI V2 3C on noctigon, no driver (direct drive), bypassed springs but thin wires to the led, samsung 25R, i don’t remeber exactly but it was a little more than 160kcd