Both links treat all kinds of subjects of which none are relevant to throw measurements vs human perception of throw.
Key is that the luxmeter is corrected to the average sensitivity of the human eye for the different colours of the visible spectrum, so it sees brightness of a target in exactly the same way.
The only difference between a luxmeter’s sensitivity and the human eye is when the target is very faintly illuminated, i.e. that water tower a couple of miles away, the eye sensitivity shifts a bit towards blue, while the luxmeter’s sensitivity does not shift. So for faintly illuminated things far away there is a point using cool white flashlights (if it is not too hazy in which case the advantage may disappear), the perceived brightness of which will be a bit underestimated by the measured lux value.
Ok. Butt just so I’m sure I understand you correctly what luxmeter(s) are you referring about? We’re not talking about LX-1330B quality level I take it.
Btw, that water tower looks a lot more than very faintly illuminated at least for me.
I know fly a well lighted drone up there with a book attached facing the Go-Pro and then take a reading. Oh wait, there may be a slight glitch in that approach.
So let me get this straight, ‘quantified’ luxmeter data at that long distance (1 mile and 27 yds) will tell me more than my own eyes which can biggly tell the difference between control and after shots just in the pics alone? The tower is OBVIOUSLY not faintly lit. It’s lit up REAL GOOD. Notice the ladder steps and their delineation. Notice the control shot. Can you see those ladder steps (struts) the same way? Of course not. Or the antennas on top? Of course not.
And then being there in PERSON seeing the difference from control to illumination is still less accurate than any luxmeter’s data?
On top of all that if the luxmeter reads let’s say .25kcd at the tower butt my eyes know the difference from experience watt your typical moonlit output mode actually looks like, I should nonetheless believe the luxmeter data reading of .25kcd instead?
You’re kidding, right?
PS. That beam at that distance isn’t going to be a small focused spot. I would imagine that any luxmeter better be just as macro sensitive as my wide angle ‘inferior’ eyes then.
Butt is that really possible for a luxmeter to accurately read diffuse wide angle light hitting a target? Must be if ANSI says so, right?
Or would a photo light meter reading actually be more accurate than a luxmeter in that case?
Something people often don’t consider is that if you’re standing with the flashlight, the light reaching your eyes first needs to bounce of the object you’re aiming at, then it needs to travel that same distance all the way back.
Is this another way of saying that our eye’s perception of a light’s output is actually in various cases underestimated depending on the reflective component of the target?
Thanks Enderman, this explains why measured lux often times don’t match the reality seen by the eyes. Seeing is twice the calculated distance.
If everything else are linear (which I doubt) then measured distance is twice the actual usable distance.
This can be done by placing the lux meter at the viewer’s location but isolating a tiny dot of lit object will be harder to solve.
ehhm, I don’t know what the discusion is about now, but I think there is at least a misconception going on: for how bright something looks/measures it really does not matter how far you are from the object, when you move away from it, the object becomes smaller but not dimmer.
To my understandings, what makes an object looks dimmer is the dirty air between the object and the viewer. It’s true it’s not getting dimmer by distance. I was proposing half the calculated distance for estimating real world usefulness.
Wait, in the real world measurement the light has to cut through air with certain transmittance efficiency (let alone the particles floating in it). The theory of throw distance theory works only for short distance where the air resistance is negligible or very close to a vacuum space. So, in this regard, I think the object will looks dimmer by distance (I’m talking very far distance here) unless we see it in a vacuum space.
For me it is one thing: He gives what collectors asks for. Vinh is willing to throw away a large, beautifully machined reflector in order to cram as many emitters as possible just to achieve insane lumens numbers. And while most of his late creations are nowhere useful in real life scenarios, I can’t deny my admiration for him going over the top with his lights.
But it’s not like other manufacturers can’t give us what we want, they just don’t want to. How long have we been asking for a 21700 version of D4S/D1S+? How long have we been waiting for a quality boost driver? How many times have we not complained how huge lights drops their output to a fraction of the max just after a couple minutes?
BTW it’s funny how lots of Vinh’s followers are confused about lux & lumens and that has developed certain attack approach by BLF members.
I think we should do an experiment where we test the amount of lux on a surrounding area of X radius that is required for the average human eye to perceive as “bright enough” before the eyes adapts to this brighter ambient rendering any additional illumination inneficient. Like how are you supposed to see past 100 feet when there’s 40,000 lumens right in front of you?
The important thing, as we are seeing develop, is manufacturers having taken note of what Vinh and many others here on BLF have been doing and are emulating the ground breakers, both in throwers and flooders of all sizes. I can see our FET+1 being copied/used in several brand lights now, maybe different processors, but still the same design.
I'm looking at lights like the ROT66 and it's a culmination of several things we've been modding to get, as well as the 50K to 60K big light showdown goin on by AceBeam/Imalent.
Being back into LED flashlight/torch market in past month (gone for about a decade), I first came across CLF and then BLF.
I have read all the posts on this thread to date. I have been looking for more information about Sky Lumen (Vinh’s) products on the other forum. The owners of his products on both forum and his own posts on this forum are very reassuring. At present, I will stay with stock lights from generally well regarded OEM manufacturers. If my LED needs and appreciation advance, I will seek out Vinh’s offering(s) then. Thanks to Vinh for his thoughtful and sincere reply and to the Vinh product owners on this thread.
I’m with you. I’ve never felt the need to bump up any stock lights, but I’ve followed him over on CPF for 7ish years. I got my buddy to revamp his battery/cell/charger setup and buy some lights. He’s now got 4-5 from Vinh and sent me his Fenix TK-61 v.4 to fiddle with for a few days.
He does good work, but I see some of the apprehension here, towards his endeavors. Face it, not everybody cares to, or is adept enough, at modding lights, so he’s one of the first to exploit the niche ‘building/modding’ business.
