Hi:
I bought all 3 Olight models (and also 3 Fenix digitals). Every one has a very flat-top and narrow hotspot. I knew they would be more throwy than Fenix (which is terribly inconsistent about focus from light to light, but a softer hotspot overall), but I didn't expect such a flat-top.
The Olights are thus unfortunately almost useless to me since I use lights mostly walking around the house at night, or in close quarters (inspection/work-light) so more floody beams are better.
I work with lasers, so let's define beam profiles:
gaussian = beam has a 1/exp(x^2) shape, or normal distribution. This is usually the most desirable shape for laser beams, though industrial processes sometimes prefer...
flat-top = beam profile looks like a rectangle. (I am talking here about the intensity as a function of position for an axis drawn through the center of the spot that the light makes on the wall, NOT that the light makes a rectangle on the wall!)
Of course, nothing makes a perfect flat-top. There is a softness to the edges. An exapmple of a very soft transition from center hotspot to spill would be the gaussian. Certainly a gaussian (or something similar) is more desirable for the following reasons:
1. It balances throw with flood. Since the central portion is much brighter than the outer regions, even a wider gaussian beam diameter can achieve a more lux on a distant target compared to a flat top. Thus even if the average lux over a gaussian profile is less than that of a flat-top of the same effective diameter (for equivalent total lumens), the gaussian will throw more and yet convey the appearance of smoothly illuminating a broader area.
2. It avoids the sense of "tunnel vision" which results when the transition from hotspot to spill is very sharp. That is what the Olights do. I don't like this at all.
Another example is Dereelight DBS vs. Tiablo A9, which I have also obtained. The A9 is more flat top. Because of this it seems useless for distances that are too close to let the beam expand significantly. Whereas the DBS has a continuous peaking of intensity toward the center. The DBS seems useable even for lighting the walk only 10-20ft. ahead, while the A9 gives tunnel vision.
It seems a particular problem with Cree LEDs, this flat-top beam profile. I think that a really crafty light maker needs to sit down with some optical design software, and design a reflector shape that produces a planned beam profile. That being gaussian or something similar with a peaking of intensity right at the center and gradual tapering off toward the spill. This reflector would likely wind up NOT being a paraboloid. It would be some arbitrary shape, that would then be cut by a CNC lathe.
This is the only way to improve this. Maybe this can be the next innovation by light makers - mathematically optimized beam profiles, with 3D surface plots measured and printed in test reports just like for lasers!
I really thought I would like the Olights better than Fenix, since Fenix is always inconsistent about focus, centering of the emitter in the reflector. (My P3D beam is significantly oblong due to poor emitter centering, the P2D is just slightly.) And I thought the memory of the Olights would be much preferrable to the Fenix, having to step through brightness levels all the time.
Now I think maybe the Fenix UI isn't so bad after all, since it isn't that much more trouble to give an extra tap or two. It might even be better than memory for me. You can't know this until you try it. But the Olights "feel" better made than Fenix (partly for the reasons mentioned).
Maybe I should have bought just one Olight first?
I will probably keep one just for collector's sake, then put two others for sale later.
I bought all 3 Olight models (and also 3 Fenix digitals). Every one has a very flat-top and narrow hotspot. I knew they would be more throwy than Fenix (which is terribly inconsistent about focus from light to light, but a softer hotspot overall), but I didn't expect such a flat-top.
The Olights are thus unfortunately almost useless to me since I use lights mostly walking around the house at night, or in close quarters (inspection/work-light) so more floody beams are better.
I work with lasers, so let's define beam profiles:
gaussian = beam has a 1/exp(x^2) shape, or normal distribution. This is usually the most desirable shape for laser beams, though industrial processes sometimes prefer...
flat-top = beam profile looks like a rectangle. (I am talking here about the intensity as a function of position for an axis drawn through the center of the spot that the light makes on the wall, NOT that the light makes a rectangle on the wall!)
Of course, nothing makes a perfect flat-top. There is a softness to the edges. An exapmple of a very soft transition from center hotspot to spill would be the gaussian. Certainly a gaussian (or something similar) is more desirable for the following reasons:
1. It balances throw with flood. Since the central portion is much brighter than the outer regions, even a wider gaussian beam diameter can achieve a more lux on a distant target compared to a flat top. Thus even if the average lux over a gaussian profile is less than that of a flat-top of the same effective diameter (for equivalent total lumens), the gaussian will throw more and yet convey the appearance of smoothly illuminating a broader area.
2. It avoids the sense of "tunnel vision" which results when the transition from hotspot to spill is very sharp. That is what the Olights do. I don't like this at all.
Another example is Dereelight DBS vs. Tiablo A9, which I have also obtained. The A9 is more flat top. Because of this it seems useless for distances that are too close to let the beam expand significantly. Whereas the DBS has a continuous peaking of intensity toward the center. The DBS seems useable even for lighting the walk only 10-20ft. ahead, while the A9 gives tunnel vision.
It seems a particular problem with Cree LEDs, this flat-top beam profile. I think that a really crafty light maker needs to sit down with some optical design software, and design a reflector shape that produces a planned beam profile. That being gaussian or something similar with a peaking of intensity right at the center and gradual tapering off toward the spill. This reflector would likely wind up NOT being a paraboloid. It would be some arbitrary shape, that would then be cut by a CNC lathe.
This is the only way to improve this. Maybe this can be the next innovation by light makers - mathematically optimized beam profiles, with 3D surface plots measured and printed in test reports just like for lasers!
I really thought I would like the Olights better than Fenix, since Fenix is always inconsistent about focus, centering of the emitter in the reflector. (My P3D beam is significantly oblong due to poor emitter centering, the P2D is just slightly.) And I thought the memory of the Olights would be much preferrable to the Fenix, having to step through brightness levels all the time.
Now I think maybe the Fenix UI isn't so bad after all, since it isn't that much more trouble to give an extra tap or two. It might even be better than memory for me. You can't know this until you try it. But the Olights "feel" better made than Fenix (partly for the reasons mentioned).
Maybe I should have bought just one Olight first?
I will probably keep one just for collector's sake, then put two others for sale later.
