Is it unfair to judge output in the snow??

LightCrazy

Enlightened
Joined
Dec 31, 2011
Messages
400
Location
USA, Western PA
I went into the woods again, 8" of snow on the ground. This Nitecore MT40 is bright, but not that much brighter than my Fenix TK15 S2. I know they use different emitters, but I expected the MT40 with 2 18650 batteries and a 2" reflector to blow the TK15 away more. When I test the lights in the house on a white ceiling, the MT40 puts a blinding hotspot on the ceiling. SO, is there really that much light reflected off the snow from the spill beam to make the MT40 appear to not be that much brighter? Even shining the lights up into the top of a tree a full 100 yards away, the MT40 is brighter than the TK15 and has a larger hotspot, which is what I want. I just can't say it totally blows the TK15 away. Stumped.
 

biglights

Enlightened
Joined
May 13, 2012
Messages
515
I have noticed that also with all the snow we have gotten lately. A couple of my monster likes don't appear as bright as they once where. The white stuff must eat up the lumens.
 

LightCrazy

Enlightened
Joined
Dec 31, 2011
Messages
400
Location
USA, Western PA
Any other help? Maybe from selfbuilt? There is s big difference in brightness of the hotspot in the house. I guess I expected the larger MT40 to throw that hotspot better than I am perceiving it. I also thought there would be a bigger difference between high and turbo. That difference appears to be much less than the steps between high and medium or medium and low. Thanks for the help. Should I have picked a different light in the same price range?
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
7,004
Location
Canada
For what it's worth, my subjective experience is that snow-covered fields make it very hard to compare the differences between lights. In essence, it's almost like the snow acts as a diffuser, spreading out the beam pattern through all the reflections. :shrug: You can see some evidence of this in my 2010 outdoor beamshot round-up (scroll down for the two sets of Jan 2011 beam pics). This is why I no longer bother trying to photograph beams when there's snow on the ground.

In this case, the MT40 is not a very throwy light for its class. But what you observe is normal in terms of level spacing (i.e., there is little subjective difference between Hi and Turbo, even though it is a couple of hundred absolute lumens). The Hi on the MT40 is not that much brighter than your TK15 Turbo overall (less than hundred lumens difference). End of the day, the MT40 probably has about twice the lumens on max as your TK15, but subjectively it will seem much less than that.
 

passive101

Enlightened
Joined
Aug 15, 2007
Messages
653
If I remember correctly LED's have more of the blue color spectrum. Blue light is much shorter then reds and several other colors. One it reflects off of water, ice, snow, etc. Their is less to be bounced back to your eyes. Hence why Yellow spectrum of light works better to the human eye in those conditions.

Every light will have less light reflected back to your eyes, but yellowed tinted ones will be longer as yellow is one of the longest light lengths

Is my information correct?
 

Norm

Retired Administrator
Joined
Jun 13, 2006
Messages
9,512
Location
Australia
I'm certain you'll find the difference is the amount of light reflected off the snow, causes your pupils to close down and less light is gathered making any light look dimmer. The same is noticeable whenever light bounces back into your eyes, try having someone hold your light and step off into the shadows and see how much brighter the light appears.

Norm
 

LightCrazy

Enlightened
Joined
Dec 31, 2011
Messages
400
Location
USA, Western PA
Thanks for the help. I just saw the TK15 and MT40 as well as the BC40 100 yard beamshots you posted, selfbuilt. I would guess the difference in the TK15 and MT40 in your pics is about what I am seeing. My TK15 casts a slightly blue/yellow/greenish tint, depending on what level it is on. The MT40 has a whiter tint, especially on high and tubo. I guess I'll do more brightness tests when the snow is gone. Not sure if I could have gotten a brighter light for about the same money as the MT40 or not. I definitely did not need the SOS and strobe modes. From the beamshots selfbuilt posted, it looks like the (and my) MT40 has a whiter beam than the BC40.
Not sure about the info on wavelengths and distance, but I am sure there is one.
 

LightCrazy

Enlightened
Joined
Dec 31, 2011
Messages
400
Location
USA, Western PA
UPDATE: Well we lost most of our snow, so I went back outside to test this MT40 on green grass and brown/green trees. I must say, the light performed much better! The light has great throw for its size and price, and offers a nice bright spill beam I can use for hiking in the woods or SAR. If I could make changes to the light, it would be to make the turbo a little brighter from the high mode, and make the SOS mode hidden. Otherwise, nice light. Any SUGGESTIONS on how to tighten the head just a little so it would stay in the user defined or turbo mode easier? I know the BC40 uses 2 o-rings for the head, which probably helps. Thanks.
 

El Camino

Newly Enlightened
Joined
Sep 12, 2012
Messages
166
Snow is basically composed of tiny crystals. The surface layer will have plenty of facets to reflect light in all direction, including those away from your eye. Also keep in mind that snow is a bit transparent, so it will scatter light into the snow. Both of these can make a light appear dimmer than it is, which is the opposite of what you would expect from a white object.

My theory, anyway.
 

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
I'm certain you'll find the difference is the amount of light reflected off the snow, causes your pupils to close down and less light is gathered making any light look dimmer. The same is noticeable whenever light bounces back into your eyes, try having someone hold your light and step off into the shadows and see how much brighter the light appears.

Norm

+1 this is exactly what I was going to say.
 
Top