I think both your lights are too close to say. With the tk70 putting out twice the lumens, all the air in front of it and the camera is too lit up. I really think the only way to maybe tell the victor is for the camera to be down close to the barn. And even then you might have to have the lights even a little further like 550m or 600m. On my long distance testing and shots that’s about the only safe wa to tell when you get distances in the ranges you are shooting at. Unless of the lights are markedly different in throw - which isn’t the case with your two nice throwers.
Irregardless they both do a great job for certain they both very close in throw.
And thanks for taking the time to do all the shots.
Don’t know if this will help, but here’s a few I took awhile back. I had these posted in my XM-L thrower thread in case you didn’t see them.
110Yds
TN31
TK70
For those thinking about the TK70 vs. SR90 vs. Microfire Warrior III shoot-out, take a look at this:
ILF, it helps. But more to make me think that your TN31 and TK70 is equal in throw.
I cropped and resized the last two barn pictures as below, and still difficult to call who is winner here.
Now why didn’t that first one post? It’s showing it to be there at photobucket. Must be something in the website here.
Yea but what about the other set I posted the nite before.
I know it is difficult to get the beams pointing at remote target so it could have some error for most beam shots pointing at remote target. I didn’t pick any pictures, just that someone ask for help in the thread to zoom in and so I did but I don’t know how to do mouse over.
And I just look at the first set, because the way the beams lights up a lot of particles in air with reflection, I don’t think it is as good as the last set for comparison. It could be brighter caused by refection. Just my opinion.
You know, you may have something there. So should we say they are about equal in throw, or should I just go do a slower shutter speed at some trees say 220yds or so away?
This is a lot less hassle and usually provides more conclusive data by eliminating variables.
Take a picture with both of them shining at a surface (at the same distance of course). Under expose it like crazy until you can distinctly make out the hot spots. Then you can make a mouse-over of the two hot spots and see which one is brighter.
Look at the brownish-leaf tree at the right side of the third post. It is even behind (meaning farther) than the barn.
Which do you think throws farther? Isn’t it the 70? Look a post #61. Somehow both pics does not appear here.
At how far would you say?
And if we just go off of the pool wall above only in the 110yd shots we can see the TN31 as the brighter light.
It can be 1 meter or as close as you want, as long as the light doesn’t saturate the picture. If your camera can’t take fast enough exposures then of course you’d have to move the lights further away to lessen the intensity of the hot spot.
Eg. 
Ok let’s try this.
20 ft 1/1552 of a sec shutter f/2.8 ISO 400
TK70 on the left, TN31 in the middle, and L3 K40 on the right
I took that one off the blue vinyl siding on the side of my house.
This is a pretty good shot. Just shows how close the TN31 and TK70 are.
Now is that way too slow of a shutter?
Let me go speed that up against those 3. It’s hard to hold all 3 lights at once. I’m putting the TK70 in between my legs to do this? LOL!
It’s a bit fast, but decreasing shutter speed would only make the spots brighter, and the difference between the two would still be nearly indistinguishable.
Well just for grins. I had to keep slowing down the shutter until I got this photo to where you could see it good and clearly.
20ft and same order as above
Manual exposure, 1/97 sec, f/2.8, ISO 400
