“REVIEW”: On The Road Z821 - Zoomable – 1x18650 – 940 lumens [Pic Heavy]

Well, funny thing is, I had it on the Convoy S2 with DD configured and it never happened :zipper_mouth_face:

It was turning blue even at 4A with DD. With CC it is normal :wink:
I can’t make measurements, I don’t have a clamp meter and my DMM can’t read too (no fuse :person_facepalming: ).

But I have it now configured to 5.5A, CC and so far no problem.
Also, when it was on DD, it got HOT in seconds (with full battery of course), and with CC it doesn’t heat that fast :wink:

“turning blue even at 4A with DD”

If enabled, DD is not limited by your settings in the driver config. It replaces the highest mode and acts like FET driver on turbo.

For testing I mean just lux meter test at like 5-10 meters. Clamp meter kind of pointless with CC driver :slight_smile:

Stupid me :person_facepalming: I read it on l4p thread some days ago and completely forgot it :weary:

That’s the reason why it was turning blue… :person_facepalming:

Ahh, lux readings! well, I don’t have many conditions in my house, but later tonight I will try to measure it at least at 5m. I will post what I have then :slight_smile:
The clamp could be good to check if it was in FET, with the OTR battery (to compare with other battery) :wink:

Yes it could turn blue because when DD it will draw around 14A of current!

Thanks to L4P I was probably first person in a world to test this White Flat 2 emitter with my redneck test(battery, lux meter, clamp meter tail readings) which is not so accurate as pro equipment but it is telling certain values:

Samsung INR 30Q FET Driver:
4.2V, 13.4A, 930 FC

4.0V, 12.5A, 950 FC

3.9V, 11.4A,1050 FC

3.8V, 10A, 1250 FC

3.7V, 9.20A, 1200 FC

3.6V, 8.20A, 1150 FC

3.4V, 7A , 1100 FC

It really is beautiful emitter but it will never go to mine single 18650 configurations because for best performance it should be hard driven.
And when driven on 4.5A old dedomed XPG2 will be better performer.

WF1 is different story… Only flaw is that it is very small emitter for larger aspherics but it should work more than fine in this OTR.

And man you gotta get yourself lux meter and clamp meter (30$ of investment).

Oh forget about that now I see that you have lux meter :beer:

BTW I have same light meter as you. Try to switch to FC mode. That way it reads much more accurate and it is very easy to convert FC to lux online.

5m measurements and convert…

I will bump mine up to full 6A CC mode and re-measure lux. Really want something closer to 100kcd out of this but I guess I will have to max out the LED with new driver or switch to NM1 to get that

Osram White Flat 1 + precoolimator lens.

66.5kcd, not much improvement

This host is not worth the complexity and cost of pre-collimator lens. I may try WF1 though.

Please try. It should be 20% brighter. So it should hit 100KCD which is extreeme thrower in that flashlight size. Do you remember those small 80-90 kcd lights that Saabluster(from CPF but he is member here too) was selling several years ago for 300-400$? At that time that was really extreme performance in small flashligt form factor. Well this should certainly surpass it in every possible way if you put WF1 inside.

Thanks for the measurements and the information on this luminarium iaculator :wink:
Well, 14A current may be a little too much for the led :stuck_out_tongue: No angry blue on this team :stuck_out_tongue:

I was going to get a UT201E clamp meter 2 weeks ago on a local store, supposedly on sale for half the price (23€) but when I reached the store it was sold out :person_facepalming: I felt disappointed. I will wait some more time, bad time to buy stuff now…

About my rough measurements (really rough, as I have no good setting to do this at home):
at 5 m, I got a) ~2290 lux peak, 2080 lux after around 15-20 seconds, and b) 206 FC, that then started decreasing.

Using the online calculator that you gently pointed me to,
207 FC = 2228.1294563l lux
2290 lux = 212.7479616 FC

2290lux at 5m = 57250cd

So, are the measurements wrong?

Driver is set to CC at 5.5A, the battery was at around 4.1V, and after being lit for a while (less that 1 minute), the light was 46ºC in parts of the head and body.
It gets almost too hot to hold when being pushed during some time.

I hope this helps in some way :+1:
And help me correct what is wrong !

Since you have different lux meter, LED, etc I dont really see any reason to think it’s wrong

I don’t think they are wrong… Possible LUX meter calibration variation :beer:
Whole BLF would need group buy of same type/same calibration luxmeter. That way we would have same results. Djozz would be right guy to take group buy since he is almost doctor for lux meters :wink:

Contactr got this before me lol :slight_smile:

But there are plenty of possible variables:

- Lens difference (only applies to glass lenses and performance may vary a lot)

- emitter brightness difference (someone gets lemon and someone strawberry)

- spring bypass (ignore that for Osram but it still matters for Cree emitters)

- Driver wire length&thickness (not much influence on Osrams just Cree)

- Mcpcb (DTP board really boosts things up)

- lux meter calibration

- Used 18650 cell

  • I can’t remember any more…

Edit:
About your luxmeter… I noticed that lux meter readings goes up if I clean sensor with wet wipes and microfiber cloth. But you can try to clean it with whatever you have. Mine is in dusty drawer and needs cleaning from time to time…

Thanks both of you! :+1:
I am not used to do this kind of measurements, much less to be “accurate” (if I could ever achieve that).

I needed to have a stable tripod to be able to stop the light and always make it in the same focal point.
Also, better tools and calibrated ones could improve the measurement accuracy. But this is still a hobby and I will only get some things I may need.

Well, not sure if the “blackened” reflector, a non existent gasket, other eventual things related to led centering, can have any kind of influence in terms of illumination. :zipper_mouth_face:

I have no bypassed springs and the tailswitch has a thinner spring , not as the original one.
DTP MCPCB from led4power. I guess it has 20 AWG wires

My luxmeter is normally in a box, with the sensor downwards, so it is not very dirty I guess.
I believe other things may have more impact on this measurement.

I guess my flashlight “science” may be frail after all :smiley: :smiley: :smiley: :innocent:

Well 60 kcd from a small light is still impressive results since a whole lot of factory lights does not surpass even 20-30kcd mark.

Indeed! It is still a good throw, given the specs and that I cannot mod it “perfectly” :wink:

BTW, I modded my Eagle Eye X3R also with l4p driver set to 4.5A and White Flat 1.
Measurements:

3090 lux at 5m = 77250cd

It does this :wink:

I went from 66.5kcd to 71.4kcd by adjusting the focus. I took an o-ring from a 26650 light and pressed it onto the shelf where the lens sits then screwed the bezel part way back on.

This is “too much” adjustment and over focused it but I gradually pulled it back until I got a more ideal result with lux meter (on low up close) then formally re-tested at longer range with highest setting.

This tells me that additional 0.5mm added from MCPCB probably does make a difference even though it didnt appear much “sharper” to me visually. Not sure of the best way to correct this yet or if it’s worth it.

Yup, to get it right and increase the numbers seems like there is too much adjustments to do. The thicker MCPCB probably plays a role, mine is lifted a bit because of the pressure/contact of the “reflector” and the board/soldered wires.

The focusing with these Leds needs to be done carefully, adjusting the lens and all the rest in order to make it “reasonable!
Despite I like the current configuration, I am actually thinking of modding it later, eventually, probably maintaining the same driver, but replacing the led. Maybe a Luxeon or something alike… But this is just a thought, not decided yet.

MascaratumB,

Reflector lights can’t really impress me(even 300 + kcd lights) but really nice results for that Eagle light :+1:

And from your pic we can all see how “useful spill”(halo effect) from reflector light awakes your neighbors :laughing: on 2 buildings.

With aspheric you could lid that tree without anyone notice you…

If you guys use L4P DTP’s they are quite a bit thinner than Noctigons so maybe just slightly focus “issue” can happen here.

Thanks luminarium iaculator :wink:
Well, I know some people can make that led perform better on SMO reflectors, almost having no spill. With this light and its’ reflector (that screws along with the bezel, it is the possible beam :stuck_out_tongue:

Yup, with the OTR i3 as I have it now, I would have almost no spill nor rings trying to do the same!
As for the Z821, maybe it had some rings/artifacts.

I believe that a Noctigon MCPCB would prevent some “extreme focus” as it would be even higher than the L4P. It would make the “reflector” almost unscrewable :zipper_mouth_face:


Today I managed to make the Z821 a bit better. I found a 3535 gasket that helped me stabilizing the led centering, so I removed the tape it had.
I blackened the gasket, the refector, the lens and the bezel. The center of the beam improved, with less “white”noise.

I compared values with the i3/M1 (with Samsung LH351D , MTN DD driver with Crescendo, 16650 battery charged to 4.18V).
The Z821 was using a Sony VTC6 charged up to 4.12V.

Both at 5m.
i3 ——————————————————————————- Z821

LUX FC Cd
i3/M1 380 37 9500
Z821 2520 227 63000

The luxmeter “disappeared” from the image due to the beam intensity :stuck_out_tongue:

I would not call that reflector… That is well made MCPCB retaining ring seen on plenty of aspheric light models but this is probably the best… Screwable function is surely better than unscrewable :laughing: :beer: . We don’t want to loose that (on flashlight of course).

:smiley: :smiley: I saw what you did there!

Yeah, “reflector” is not the best word/expression, but I was not finding a better one :zipper_mouth_face:
In other zoomies normally it is a plastic piece that acts as gasket too, but in this we have the proper gasket, then that metal “part” :stuck_out_tongue:
I will try to find a proper spray to make it better blackened than with a black permanent marker.