Awesome work turboBB ! Thanks !
Nice, I live right by there and was going to do a similar test off the Palisades Interstate Parkway cliffs, but was worried that cops would come by and actually take my GT away. You know how NJ is!
Nice video!
Nice!
Interesting to see how this performs in a dry winter air 
At 1:52 you’re lighting up reflectors on the hillside :sunglasses:
Nice video
Thx guys!
@Zulumoose - going to go back during the daytime and get my bearings and retry the Yonkers sign. At that distance and at night looking at a tiny LCD screen I just couldn't make it out...
@Dengoh - nope, it's 1.72 miles actually but I rounded down
@Throw me in to - "This watch I got here was first purchased by your great-grandfather..." 
@EasyB - at that distance I honestly couldn't tell if it was lighting up at all, it seemed like it did but I was trying to be careful to not get the beam in same line as the lens since it might just be the beam lighting up the atmospheric dust. Going to retry now that I've gotten a feel for the settings required (wide-angle cam was D850 with D500's 2.25x crop factor on that building - may reverse next time thinking the better light capturing capability of the FF sensor on D850 would offset the loss of crop)
@llmatic - funny you should mention that, the state troopers were actually there at the time and I cleared my activity with them (but I didn't have any equipment out yet... had they saw the beam, it might've been a different story... 
)
@beachlogger - Wow sharp eye, I didn't even notice that earlier. So I got a comment on the vid that lighting up signs was not a good way to test, but that was totally coincidental (serendipitous even?) since I didn't even know much less could see that those signs were there. I only noticed them while editing the vid at home. However regardless how reflective they are, they won't defeat the laws of physics for light fall off. I also had a TN31 with me that would certainly not have lighted those reflective signs up at 1.7 miles let alone anything else across the river. :)
EDIT: I checked out the maps and believe that sign on the hillside is most likely at the intersection of Glenwood Ave and Ravine Ave (2 miles from my spot):
EDIT 2: Or potentially Phillipse Pl one block behind it.
More testing to come but suffice to say, my PVC LMD won't be able to accomodate the size of this light so while I can do runtime, won't be able to provide "accurate" lumens measurement.
Most impressive video and flashlight! Thanks for posting turboBB.
That’s just the beam giving the impression of lit up.
All it’s lighting up is dust and humidity.
The only way to tell that the light is actually reaching that far is the reflective signs.
In order to see the target properly without the beam getting in the way you need to either be standing at the target or be several dozen or hundred meters to the side of the flashlight.
Some of it is from the lit up dust, but I think the camera is detecting a lot of light hitting the building. If it was just lit up dust in the foreground the image would appear brighter uniformly, but you can see the contrast of the vertical stripes on the building increase. I don’t think this could happen if it wasn’t lighting up the target.
lf it was only dust that lighted up the building, it sure was a “smart” dust as to follow the shape of the building!
Wow, great vid mate!
This was my impression too. In the close up you can see the whole area of the beam lighting up even besides the target. Contrasts are decreased in the beam. And with all the humidity/dust the seemingly increase of brightness on the target is much more than could be expected at this distance.
But the contrast of the building features increases. When the beam is off you don’t see the vertical stripes, but you see them clearly when it’s on. This wouldn’t happen if it was just lit up dust.
I think it probably appears much brighter than it would look with the naked eye, but that is just an issue with the camera exposure.
This might be due to the brightness and contrast settings and viewing angle of your display. I can see the stripes clearly without beam. Try to look at your display from a different angle.
I captured this vid using two cams:
D850 w/50mm [4k 24p | 1/50 @ f/1.4, ISO 1600, Direct Sunlight WB, Flat] captured the "wide" view with the city
and
D500 w/70-200 [4k 24p | 1/50 @ f/2.8, ISO 6400, Direct Sunlight WB, Flat] w/2.25x crop factor capturing the zoomed shot of that building.
I'll post the original un-cropped and de-noised vid from the D500 later. The reflective sign that beachlogger pointed out was at least 2 miles away and easily seen in the vid. As I had stated, it wasn't my intention to use them (didn't even know they were there) and I agree it's not a great indicator of throw but it still observes laws of physics wrt light fall-off relative to other light sources. I also had TN31 XM-L2 and didn't notice anything being lit up at the original target @ 1.2 miles.
Yikes!! I’m just across the pond. That’s quite a few GT’s in a small radius. We might be able to reenact some Light Saber fight scenes across the river.
And yeah, PIP police have a reputation!! Don’t they often hang out at the lookouts? They got a couple of traps in that area.
It’s a good area for flashlight tests, there’s almost no lighting there.
I’m curious what it would be like to test the light from the other side of the river, trying to light up the cliffside and the boat basin/picnic area. There’s little ambient light on that side.
Cameras and computer displays are digital, so they have stepped output levels unlike a continuous analogue signal.
This means that you can increase/decrease the overall brightness of a scene equally and this will cause contrast between certain objects to increase or decrease.
High dynamic range is a newer technology which allows more visual information to be recorded, however very few cameras and displays use this today.
It’s also still not perfect like analogue.
The amount of light hitting the target at that distance is less than 1 lux.
Unless there is no ambient light and no moon out you will not be able to see the difference.
If you are at the target then you may be able to see a slight increase in brightness, but definitely not from 3km away.
After further review of the raw footage and if the 1.29mm CD spec is correct then I'm inclined to agree with Enderman that most of what was caught was unfortunately reflected light due to atmospheric dust / humidity. I'm happy to redo this using lessons learned from this first try when the weather warms a little and would love some help from those nearby, we can also take samples of each of our lights so we can see the variations between them. Would also be interesting to catch the end of the beam from across the river with a third camera to show exactly how much illumination is being cast across. More to come and please PM me if you're interested in helping.
EDIT: I've also wrapped up both 4S1P/2P runtime plot on Turbo using the Samsung 35E's they sold with the light and added to OP but posting it here as well. NOTE: I must stress that the Lumens measurement here is not accurate given my PVC LMD is just slightly small to accommodate the head, I also removed the sheet of glass I normally rest the lights on to help offset of some of the lumens loss but the duration and overall relative output is "accurate":
4S2P now completed and chart updated in previous post as well as OP.