Group Buy: TKLamp Flashlight Tester integrating sphere (now taking orders, shipping in march-april)

UPDATE 21 Feb: 8 confirmed orders, 2 more needed to secure production.

UPDATE 20 Feb 2024:
The product page is now live to order the datalogging version, production will be confirmed once there are 10 orders. Still open for anyone else who wants to get in on the group buy.

The base price is $400, plus $39 shipping to NA/Europe. In addition, there will be a $10 rebate per tester (refunded to original payment method) if we reach 15 ordered in total, and $25 if we reach 20.

Thanks to everyone who signed up for making this project happen, I couldn’t have ordered 10 by myself :stuck_out_tongue:

Original post:

Product: (edit: link updated)


TKLamp Discord: TKlamp Lighting Lab

Have talked to TKLamp a bit about this, and it’s really promising, a decent integrating sphere for $350 with no calibration needed (free recalibration at any time if you ship it to them), and, from my conversation with them, good enough repeatability (~1% variance) that it can be used as a reference to make calibration lights for other equipment too, plus it has a separate external luxmeter for measuring candela.

I asked them if they could incorporate datalogging into it too, as their other product, a car headlight tester, incorporates this, and they said they could if there was enough demand, and if I could get a group buy of 10+ then they could make a custom version with those capabilities.

The entry port size is a little too small for some of the biggest lights, but if you have one it would be easy to make and calibrate a larger tube/sphere for those using it, and the maximum brightness is 13,000lm, but it would be easy to just add an ND filter to the port to test higher outputs (or use it to calibrate a tube as mentioned above).

Price will be $400, possibly $350, although if I get a decent sized group buy together, might be less, so I guess post if you’re in for $350 or if you are interested if I could get us a lower price.

So, who wants an integrating sphere?

Crossposted with Reddit, we need to get 10 people signed up to get this version made. Reply or DM me to sign up, you can be listed publicly or privately, whichever you prefer, but I will keep this post updated with number of slots filled. Probably no quantity limit, but a minimum of 10.

  1. Wolfgirl42
  2. LiteintheNite
  3. /u/containerfan (reddit)
  4. duckie
  5. yasenf
  6. /u/fixeverything2 (reddit)
  7. LeaveMasonAlone
  8. Anonymous
  9. Anonymous
  10. peartrie
  11. Anonymous
  12. /u/-nom-de-guerre- (reddit)
  13. Anonymous


  • Temperature compensation: Yes, it uses a temperature compensated sensor.
  • Warranty: Have asked, awaiting response
  • Datalogging on candela reading as well as lumens: Have asked, being looked into.
5 Thanks

Generally interested, if Datalogging and import to germany is possible :wink:

2 Thanks

Hey! Why did my post about this get no replies lol. If anybody didn’t see it already here’s a video of a guy using a sort of prototype version to test some lights if anybody wants to see it in action.

2 Thanks

Interested if datalogging is possible.

1 Thank

Got a few updates from TKLamp.

Both lumen and candela have "continuous" reading. Sample rate is 1 second. 
Resolution of lumen/candela measurement is 1. 
Warranty: 1 year warranty against manufacturing defect. 
Distance adjustment and candela calculation: we need to do more research on order to make sure the calculation can be done right  

In terms of the datalogging, they’re looking at how they’d implement it but it does seem like it should be doable for both lumens and candela. Still discussing temperature compensation and specified distance for candela (I also suggested that if a custom distance can’t be worked in, if they just gave an option to display raw lux then we could convert to candela ourselves with a known distance).

Completely missed that, I know the sphere has been discussed on Discord a few times but afaik nobody actually reached out to them for detailed specs until I did.

1 Thank

I’m just joshing lol. Ya probably. The flashlight version only showed up on the site what, like last week? In that video he talks about trying to convince these guys to stock a flashlight version, because his was custom modified. That was 2 weeks ago, I watched the video the same week and the flashlight version was on the website already. So pretty new.

You could message that YouTube channel, they might be able to tell you somethings the manufacturer won’t, idk, just cuz they actually have one (maybe 2?) currently.

I really hope they put data logging on it. That’s an essential.

The only thing i have a concern with is that the numbers they measured with that video seemed slightly high. They didn’t measure enthusiasts flashlights so it’s hard to tell, not a lot of reviews on a Coast flashlight, but the streamlight made 130% of its lumen claim? Every flashlight except 1 made more than the advertised lumens? When has that ever happened lol. That’s a little sus.

But the nitecore, the one that didn’t meet advertised, has reviews and the lumens they measured are the same as everyone else’s so maybe it’s fine and we just haven’t been giving Coast enough credit lol

Got some more info from TKLamp yersterday. The sensor is temperature compensated; they’re looking into the candela calculation with regards to the distance; I also suggested that if distance adjustment can’t be incorporated directly, if it could just display raw lux then we could do the conversion ourselves.

Still looking into exactly how the datalogging would work.

1 Thank

I am interested, data logging would be a big plus

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Cool. If they can add datalogging for the same price it’s a good deal for someone who doesn’t want to diy one of these.

EDIT - I just saw you already stated the lumen limit in the top post, my bad :sweat_smile: The 13K lumen limit makes it less appealing, ideally they could include an ND filter designed to fit the aperture properly.

(Left on video about Imalent SR32 - it could be a typo potentially)

I’ve been very interested in this product ever since the Torque Test Channel showed it off in his video. If it’s truly very consistent, it could make a great new standardized testing system for hobbyists looking for accuracy, data logging would be really nice too.

1 Thank

I feel like even 13k isn’t too bad - I’ll probably build a larger tube than my current one (4.5in) and use the sphere to produce a set of calibration lights to get the large tube calibrated for higher output lights. Certainly, there’s a lot more headroom in 13k than if it was e.g. 5 or 6k.

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That’s what I was considering as well LOL, it should serve as a decent base to calibrate a light for larger spheres. The aperture is pretty small anyways

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We’re halfway there… :slight_smile:

TKLamp also have a Discord if anyone’s interested in talking to them directly: TKlamp Lighting Lab

The above link is dead. Is this the version: 🔦 TKlamp Flashlight Tester 2024 New Version (pre-order now, shipping in January 2024)?

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I will pass, the last thing I need is another flashlight tester integrating sphere. I already have one in every room.

Yes, they updated the typo in the URL :wink:

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These start shipping yet?

If this is still going, I’m in.

The non-groupbuy version, yeah.


What coating is used in this sphere?