Hazy blue glass in L2D-CE?

[evilr00t]

Second part, question thread.

The new L2D-CE Q5 I received has a 'hazy blue' effect on the front glass when lit. See image.

Yeah, I hate it. None of my previous L2D-CE's had this hazy blue glass effect. Anyone else with a L2D-CE that does this? Is this a defect?

EDIT: Might actually be the Al reflector. I think I might have seen this in one of my early-model 18650 YJ-18WA's...

It looks like a plastic film on top of the reflector, actually. Except there's no specular reflection...

Okay, I checked the reflector with my UV modded Ultrafire WF-502B. It's probably not plastic on top. Unfortunately, the UV light pinpointed a piece of dust trapped inside my L2D-CE Q5's head! Nooooo!!!!!!

So... optics and physics gurus! Why does the new Al reflector look blue when viewed at an angle? (It couldn't possibly be rayleigh scattering?)

 

[Marduke]

You'll need to resize your picture to 800x800 max as per the forum rules.

 

[Yapo]

whats the matter? the beamshot actually looks nicer and warmer. You sure it isnt the colour reflected from the blue surface your light was lying on when you took the photo?

 

[evilr00t]

whats the matter? the beamshot actually looks nicer and warmer. You sure it isnt the colour reflected from the blue surface your light was lying on when you took the photo?

I think I'm pretty sure it's not the glass now; I think it's the Al reflector (though it would be rather hard to be certain; it's impossible to tell.) I was REALLY worried because I thought that perhaps Fenix screwed up the application of the AR coating on the front glass and I was getting reflected light back into the flashlight (which is an automatic 9% lumen penalty, and also dumps heat back into the LED) or left some sort of polymer film on the aluminum.

I'm very sure it's not the colour of the mousepad. Two different front pictures are in the image; one on a black surface, another on the mousepad. Yeah, the beamshot is warmer--not sure I like that too much--but it is definitely a bit brighter and MUCH smoother. I'll take that any day.

Also, I'll take the no 'turbo' on turn-on with the new flashlight. Always startles everyone when I turn on my old L2D-CE.

 

[orcinus]

It's the optical coating on the reflector.
Nothing to worry about.

The reason it looks blue is because it's filtering out the lower frequencies at high incidence angles (i.e. making more of the "yellows" reflect/focus toward the center of the beam).

 

[qwertyydude]

Those advanced coating like camera lenses are also partially dicrhoic in nature, instead of absorbing the longer, yellower wavelengths it reflects it back in and more yellow gets directed straight forward into the hotspot as previously stated. Blues, shorter wavelengths tend to pass straight through and so the spill area looks blue but on average the light is not wasted but redirected to make a warmer hotspot, at the expense of slighlty bluer spill.

 

[nanotech17]

check out the banner ad for eagletac above the OP - notice one of the flashlight that has similiar effect on the lens?

 

[evilr00t]

Question resolved; new coating on aluminum reflector for less blue hotspot. This makes sense with the yellower output of the light engine; color rendition is noticably improved. Thanks all!