Got it thanks. From Zeroair article I should have used 225,000x4=900,000, giving throw of 949m? Thanks.
Up to you, it’s all about what you are interested in. That calculation would give you the ANSI FL-1 throw, but it’s up to you what you are into. Selfbuilt was a well known and respected flashlight reviewer from a few years ago (at least he was over at CPF). He has a good write up of the ANSI FL-1 standard here Testing Standards – Selfbuilt's Flashlight Reviews.ca
I was just curious if there is third party measurement of throw that comes close to Wurkkos’s claimed throw of 952m. Good to see Zeroair’s number matching it.
That article has a good explanation - thanks. Now I do notice 1lumen, etc. also mentions the 30 sec delay in their throw measurements.
I emailed flashlightlens.com expressing my concern that the 52.1mm lens may be too big and ask if they could measure a few and select a smaller sample to send me. It’s such a small order I didn’t expect much but to my surprise immediately got an answer. What service!
So fingers crossed. Can’t wait to try it out; I’ve read nothing but great praises for these lenses.
email quote
Hi - It looks like the 52.1mm v3’s are running on the lower side - all the ones I’m measuring are unde by a few hundredths. Let me know if what I send doesn’t work and we can get you something that does.
That is very impressive customer service! I’m curious if it is the rose or green tinted AR coating, a lot has been written on the impact on the tint of the beam. I have the same curiosity for the ones Simon shipped, it seems he has moved to the green tint for the newer lenses, but it seems to be a bit of a lottery. I’ll be watching this thread to see how it goes!
I’m also debating with myself if I should attempt a delens. Vinh from Sky Lumens made a video about it, said he typically sees about a 5% increase in output. It seems like a fairly strait forward operation, but it is a very expensive emitter ($32+ from Convoy plus waiting for delivery) if I screw it up. It also seems it would require removing the MCPCB from the host, so a little desoldering and resoldering action. Not sure it’s worth the risk and effort for 5%.
I’ve gained more experience with ceiling bounce test (thanks @2100), with results more consistent and repeatable. One of the bathrooms in my house, the one without windows so I could test all day (grin), was the test “chamber.” I did multiple measurements of High (highest of the brightness steps) and Turbo: 1 click to high, double click to Turbo immediately. Each time the battery was then recharged to full level and flashlight allowed to cool down.
Followed is the result of Samsung 40T vs Wurkkos battery in TS30S with SBT90.2, an extremely powerful & current hungry LED. Even given the “approximate” nature of a ceiling bounce test, the Samsung battery surprises me. Not just because the gain is so significant, but that equally high gain is seen in High mode. The difference is very obvious and as mentioned repeatable.
In Turbo mode, the gain of Samsung 40T over Wurkkos is around 15%.
In High mode, surprisingly the gain is equally significant, around 14%.
The test was repeated multiple times to confirm the incredible gain.
EDIT 11/9/2022: I finally got around to measure output with my Texas Ace Lumen Tube:
Stock Wurkkos Battery ~3980 lm
With AR lens ~4090 lm (~3% gain)
With AR Lens Samsung 40T+ ~4750 lm (3% + 16% gain) 
:+1: 
Second Wurkkos battery is better, measuring ~4160 lm stock. Samsung 40T’s gain over this battery is 11%.
The AR lens I used is UCLp Acrylic: UCL Lens - Flashlightlens.com - Online Store
Without doubt the Samsung 40T makes a big difference. The 4 Samsung batteries I tested got 4520 lm, 4730 lm, 4730 lm, and 4750 lm.
2 Wurkkos batteries:
That’s a very significant improvement, 18650batterystore has 40T’s on sale for $4.99 and I think his is enough to push me over the edge. Out of curiosity, did you see an equivalent change in throttling behavior? Unlike the other changes discussed, more current means more heat more faster I assume.
Yes even with the non-exact nature of ceiling bounce test and my amateur level testing, the increase in brightness with Samsung during instant on/off test is unequivocal. I am going to test internal resistance of the Wurkkos to make sure it’s functioning well. My Opus supposedly is one of the few chargers that could test it accurately.
Step-downs between Samsung and Wurkkos: Unlike instant on-off test, run-down measurements from a Turbo start are quite a bit more complicated, takes longer to do, and longer to recover, so I’ve only done two runs for Samsung and one run for Wurkkos. All I could say from these runs is that at 1 and 2 minutes, I can’t detect a trend and the variation from run to run is too much to rely on just a few runs. Having said that, the numbers for Wurkkos battery ARE approximately equal or higher than Samsung battery at 1 and 2 minutes. This should be considered a gain for “Wurkkos” and perhaps supportive of my “theory” (lower heat of Wurkkos leads to less severe step-downs) since at least the Wurkkos is not less bright at lower level. I hope I’m making sense here 
.
Bottom line is Samsung battery makes a big difference at Turbo and High brightness levels and I agree it’s a must for this light. At least it’s only a few bucks at 18650batterystore, where I bought mines from. Samsung 40T 21700 4000mAh Battery (40T3).
So I broke down and delensed the SBT90.2 in the TS30S. I did my best to capture some before and after numbers but take these with a grain of salt as my setup is far from scientific. Overall I rate the difficulty of this procedure at 2/10, very easy, assuming you are comfortable with tinkering and doing some basic soldering.
All measurements taken at turn on with an Opple Light Master Pro @ 5m by a laser measure. The light master doesn’t have a very fast refresh on the lux measurements so there was a bit of trial and error to get somewhat consistent results. The output drops off very quickly. I set a fan up to help reduce some of the variability. The light was turned on at very low mode, aimed, and then switched to turbo. The cell was allowed to recover between measurements.
Before
Best: 230kcs
Repeatable around 225kcd (There was a learning curve and I have fewer quality data points here, but this is fairly generous).
After
Best: 247kcd
Repeatable above 235kcd with several runs over 240kcd
The before numbers align surprisingly well with the measurements taken by 1lumen, which is a pleasant surprise and makes me think these are at least plausible, although definitely not what I would call scientific. I would caution anyone not to compare these to measurements taken by other people (or maybe even me).
These also line up well with Vinh’s estimates of a roughly 5% increase, and in fact are a little above. I would recommend this modification if you are comfortable with necessary skills.
I have photos of the process and will post them shortly, need to get sorted with Imgur and figure out how to embed them here.
1 Thank
The promised photos
Untouched
Bezel rand reflector removed
Removed the centering ring
MCPCB removed and thermal paste cleaned
Carefully removed the lens (I tried to get an intermediate photo but the lens popped loose)
Applied the thermal paste
Reseated the MCPCB
Resoldered the leads
Returned the centering ring
Reassembled
1 Thank
Very nice - thanks for sharing.
The lens likely is not AR coated so causing transmission loss? Is that the reason for the gain?
I’ll have a closer look at it but it is supposed to be coated. Any lens or optic will cause some transmission loss, that’s one reason OTF lumens are different than emitter lumens (reflecors are also less than perfect).
AR coatings help reduce transmission loss due to reflection, but there will still be losses due to absorption, refraction, etc. They are also imperfect, drastically reducing reflection losses but not eliminating them completely.
Here is Vinh’s video if you are interested, it’s a bit long winded and doesn’t talk about the losses much, but it is a good walk through on dedoming and delensing various emitters. SBT90.2 De-Lens VS Shave Dome VS De-Dome - YouTube
The UCL lenses are here. The 51.3mm lens fits perfectly, 52.1 mm fits barely but does drop in without any pushing. Thicknesses of either are good.
Initial observation is that the coating makes the lens looks like it’s not there (same as what happens when eyeglasses are coated). It’s a strange (and beautiful) thing to see. As for the gain in brightness, testing for gain is more difficult as the gain is small and seems inconsistent; the result so far is at best *around 4*. Definitely, gain from AR coating is not nearly as large as the 15 gain of Samsung battery over Wurkkos battery.
If you are going to switch lenses, keep in mind there are two rubber rings: one below the lens “sitting” on reflector, and one above the lens “sitting” on bezel. Importantly, I have no way to confirm and not 100% sure, but it seems to me the one on the reflector is smaller. At least in my light, that’s the only way they fit nicely.
Awesome update, I broke down and ordered some 40T’s and a 52.1mm lens. I still have the Convoy lens coming from China, but I am weak and impatient. Hopefully the lens I receive is also slightly under sized and fits without issue. This light is less and less budget every day, but even after all the tweaks and batteries it is still a huge bargain. It’s hard to put a price on fun, and this light has provided me a lot of that so far.
If my measurements were anywhere close, then we get to start stacking some interesting gains. 4% from the lens when I get it, 5+% from delensing the emitter, and 15% from the 40T. And I will never know if these changes make a noticeable improvement, but it still makes me happy.
This thing is a beast too, lights up my 200m street end to end like it’s nothing!
Comparison of the tint of different lenses using light bulb reflection “method.” Basically I put the lens on dinner table and look at reflection of the chandelier’s light bulb above it, using the lens as mirror. This method “amplifies” the tint of the lens and makes it easy to see. In non-coated lens, there will be NO change in color. With AR coated lens, the light bulb usually looks green as with my Convoy lights and my coated eyeglasses, but there are exceptions as seen here with the UCL lenses.
Here’s a good article on why typical AR coated lenses (and AR coated eyeglasses) reflect green when looked directly down on it and purple when looked at from the side: http://rick_oleson.tripod.com/index-166.html . I don’t know why the UCL lenses take on different colors, but do know that they work perfectly and recommended as a must-have for the Wurkkos (hint: I have measurements coming 
) .
UCL Acrylic Lens
UCL Glass
Convoy S21D
I’ve struggled to get consistent results in comparing the lenses, made more difficult by the fact that gain in brightness from lens improvement is very small compared to battery gain by upgrading to Samsung 40T. For example every time I changed lens and repeated measurement, I would get a different number from the last trial. If the variation error, for example +/- 20, is larger than the improvement, say +10, then it’s impossible to reliably prove anything.
After several attempts and adjustments, two changes brought success with consistent/repeatable results:
- Removing the bezel and compared lens without bezel in place. Comparison now done “live” without interruption, like changing slide in a projector.
- Testing at lower brightness (2 steps down from highest step) to remove auto temperature regulation from the equation. No more change in output during a test.
Raw numbers are meaningless in ceiling bounce tests; just want to show example of one set of numbers I’m dealing with.
No lens 247
Coated UCL 243 (~1.6% output loss)
Non-coated OEM 233 (~6% output loss)
Impressively the UCL lenses achieved ~98.4% of max brightness, and ~4% improvement over OEM non-coated lens. BTW, the 2 UCL lenses run very close, in 243-244 range, but UCL acrylic hit 244 max a few times, while UCL glass got 243 max.
This is best I could do with my amateur skill and “equipment” lol, so pls take with a grain of salt .
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Great job getting some repeatable results. On your advice I ordered a UCL glass lens and it’s very impressive. The AR coating seems to be very effective while bing rather subtle. I have a convoy AR lens on the way that just landed in the country, so it may be possible to compare these if I can get consistent results like you did (I expect to receive it in the next week or two, and there is no telling how well it will fit).
I have struggled to measure the improvement from the 40T using the Opple. The light heats up extremely quickly and I haven’t had a lot of time to mess with it. I did attempt to get CCT and DUV measurements with the stock and UCL lens, but it did not register a meaningful difference.
I wish I had taken pre and post de-lending measurements on something other than turbo, but I was excited to try to get max numbers. I just got a new puppy this weekend so I’m not sure how much time I’ll have to attempt this in the next few weeks, but it does give me more opportunities to use the light on walks at least.
Thanks and congrats re. the new puppy. Must be very cute but hopefully not chewing up things?
For battery test, yes light heats up very quickly and causes fast step-downs in brightness. The reading therefore must be immediate. In other words: one click to turn on, two clicks to Turbo, then read output immediately within a few seconds. Then turn off, recharge huntil indicator is green, then next reading after about 1 hour or so. Also, I mark positions of both light sensor and flashlight with masking tape so they’re in same exact location each time.
Unlike lens comparison, for me the battery comparison was easy since improvement is so large. After your post above, I re-run the test and just one run nailed ~15% gain from Samsung 40T over Wurkkos.
I may also have gotten some bad 40T’s. They came in with an initial voltage of 3.43v, I only charged one of them so far and it took 3600ma to get to a full charge, which seems like it was not necessarily healthy to start. It seems to have dropped voltage and capacity extremely quickly in my testing and didn’t seem to perform at the level I expected. I may call 18650batterystore and see what they have to say.
And yes, the puppy is amazingly cute and we are doing our best to set her up for success by not giving her the opportunity to chew up too many things.
OT - Tripod mount that I used for my beamshot shoot-outs in case anyone is interested.
For me this is better than the smaller rubber ones commonly seen as its diameter is about 5 mm bigger and the velcro strap provides additional safety.
Seller is legit, for me anyway: https://www.aliexpress.com/item/2251832688558005.html?spm=a2g0o.order_list.0.0.21ef1802x4tfGX&gatewayAdapt=4itemAdapt
