TK75 vs BTU Shocker - Let the battle begin! (NEW UPDATE ON POST 125)

If TK75 get better lumens in Turbo mode than BTU, TK75 is already the winner by a lot. Look at the size of BTU, it should not let TK75 get close to its performance at all. And still doesn’t out throw TN31, I am really disappointed with it, TK70 2200 lumens is already so close to TN31. Why a 2880 lumens BTU still can’t manage to beat TN31. Something is wrong with the torch. It doesn’t perform as it should be judging on its drive circuit and size.

Thanks for taking the time to do this and sharing it with us!

Very nice comparison by the way. Thanks for the effort. :slight_smile:

Oh No! This comparison makes me want to get TK75. I must resist. RC40 is at the corner.

I agree and disagree about the TN-31because I just exchanged mine and the one I was sent got spanked by the original one I got.Lux was definitely lower on the new copy,in fact the old one washed out the new at 100 ft no problem and white wall test was just a crushing.It just shows even the same light can be different,and I was very surprised and confused by the results.Lux differences in multi emitter lights have been tricky to figure out just why they are lower than single emitter lights,so I get what you are saying about the TK75.

Maybe this makes the BTU should drop at least $30 on its price. :stuck_out_tongue:

Truthfully at most distances they look pretty close. The TK75 wasn’t as spotty as the BTU and made finding the hot spot at distances trickier. However the BTU offers more flood to go along with its slightly tighter spot.

You sir are mistaken. The BTU is a light that throws 700m and puts out 2880otf at 30sec - nothing is wrong with the torch. And beating a TN31 isn’t exactly an easy task for triple led lights. And the BTU does 124K vs the 126K I got tonite with the TN31 - both super close.
I respect anybody’s desire to get the TK75 - it’s a bad arse light. I like the BTU better, but I assume many will prefer the Fenix name and its lighter weight. To each their own you know. But to say there is “something wrong” with the torch is quite simply wrong. That’s a fact.

I actually suspect because I am suspicious guy, that current new TN31 are not using good material compare to old one. Thrunite is definitely doing engineering change if the price reduce from 200 to 139. I grabbed the first batch of discount where they at first plan to have limited 20 units only. Later Thrunite extend the discount until now. So I suspect new batch is not similar to old batch. Heat will affect XML performance by a lot. Both ILF and my TN31 out throw TK70 slightly, so I expect the very hard driven and U2-ed BTU to out throw TN31.

Maybe it is the reflector and AR lens that let TK75 win this time. Every parts play a role.

I was on the shining end meaning I held the lights and got the best view obviously and believe me both lights lit up the whole road and surrounding area for hundreds of yards. I have to say the BTU looked like it threw a little farther and was slightly floodier. I personally do not see anyone being disappointed in either one of these beasts.

I am stating the fact. BTU is heavier so heat sinking should be better, driven harder so output should be higher, but the fact it is not. So something is wrong with it. If Fenix drive harder and put U2 in their TK70, it will beat TK75 easily.

I have to say I wonder what a BTU would be like de-domed,I don't have the nerve to do it but it would be interesting to see what happens to the beam.Sorry if I'm going a bit off topic,I have never seen this done.

The TK75 did not win in throw. Was short by about 30k and almost a 100m. The TK did have a slight lumen edge and did still throw its butt of considering it has a smaller reflector. Again it’s a great light.
And my brothers TN31 is a fairly healthy example with it’s consistent testing in the mid 120’s. And ever test I’ve done on the BTU also puts it solid in the mid 120’s. But I still give the TN a slight edge since most tests done together put it a couple k in the lead. Of course 2k at those distances is equal to perhaps 5m.

If you go with the TK75, you won’t regret it. Again I love my BTU and wouldn’t consider trading my brother lights, but its mostly a personal taste thing. I actually prefer the beefier feel of the BTU. But likely most people would prefer the lighter weight of the TK75. And if you intend to use one of these for long carry at work - the TK75 is the obvious winner there.

The TK75 weighs less than the BTU by a fair bit and is even lighter than my TN31. To me it feels good in your hand. It is a very well thought out design.

That would be an interesting experiment. If it goes along with other XML’s, you might end up with a 2000otf 900m thrower. Would be impressive if it worked that way. But I’m not brave enough to try it and I don’t wont to lose 1/3 of its output, even though it has some to spare.

I trashed 3 XML’s attempting a de-dome,so I gave up.Thanks for all the good info about these two lights,I think I know which one I want now.

Very informative and even-handed comparo. Thanks.

The thermal pathway is often more important than sheer mass.

Fenix continuous Turbo runtime is 75 minutes with their 2600mAH 18650s, that means each battery is drawing 2.08A in Turbo mode. Total is 8.32A with 4 batteries, drive 3-LED, that means each LED is getting 2.77A if no loss. All these show that TK75 is very well designed in efficiency and safety for both batteries and LEDs. I don’t blame BTU can’t meet Fenix efficiency. But lumens wise it should win all the way, now BTU only advantage is throw of 100m more that is not practical at all. And I can tell you my practical gain from SR95S UT compare to TK70 is only the 100m-200m range. Below 100m, SR95S UT is brighter but TK70 flood better. Beyond 200m human can’t see very clear anymore unless it is very big object at distance.

rdrfronty, do you have lux number for 5m or 10m? Would like to see how the lux number compare to 50m lux number.
At 50m, it will be 2500 multiplying lux reading. Your lux reading for BTU will be 124k/2.5k=49.6 lux, and TK75 will be 94k/2.5k=37.6 lux. These readings are close to noise floor if your meter is not good enough.