Does your flash light(torch) do this?

If it's okay, I decided to start a thread to let new users know what to expect when they own a torch. I am finding out as I go with use.

What I learned today, if its cold, and you use your torch in the highest setting, you will get internal condensation right in the centre of the lens.
It is not a big deal, after a minute or two being off, it will disappear. This is from a Thrunite TN11S...

[/IMG][/IMG]

The neat thing is that the light from the LED, intercepted at a rate of 2-5% by the glass, is enough to warm the glass differently in the middle than in the sides. The center of the lens passes the least light with a deep reflector like that, and it stays coolest, longest. The temperature difference under the right conditions can drive moisture to condense inside. So we see that 3% of the photons are enough to heat up glass. Neat, huh? Lights have come a long way in raw output.

bdogps said:

If its okay, I decided to start a thread to let new users know what to expect when they own a torch. I am finding out as I go with use.

What I learned today, if its cold, and you use your torch in the highest setting, you will get internal condensation right in the centre of the lens.
It is no big deal, after a minute or two being off, it will disappear. This is from a Thrunite TN11S...

Click to expand...

Yes, you get this with high powered lights (TK70, TK75, etc ..), when running them on turbo mode.
To get rid of this, you should use some silica gel packets. After using the light, remove the batteries, place the silica gel in the battery tube near the head, and put the tailcap back in place, so as not to let more humidity get into the light. This should take care of the condensation on the lens.

I never had this problem and I have taken most of my lights out into -20 -25C temperature for more than minutes... The head is supposed to be sealed completely airtight on any light with an IPX rating over 4, but there is still a possibility the head was assembled on a humid day, I guess.

How cold of a temperature are you talking about?

Although condensation is not an issue since it will go away after some time of switching the light off, in some cases it seems to adhere permanently to the lens. Many of my FourSevens lights had a blurry coating under the lens. Some of my Chinese made lights exhibit this blur coating too. None of my Surefire, Elzetta, Malkoff, HDS, and Prometheus does that. Has it got to do with the vapor emitted from the solder paste during high temperature? Not sure but it is frustrating to see things like this happening.

I dont get it normally but on my fully sealed D25Cvn if it gets tosty warm after a few mins and you go from a warm house to a vertyncold night / place it under water it will get it, it is in the centre to and can take up to 24-48hr to go but nornaly only a few hours depends how bad.

I found reseating the oring stopped the really bad fogging up where it fogged up a lot and very easily, but it still fogs up a bit these days under extreme temo changes but nornaly only for a a hour or two.

Pretty cool though, I know its water tight as left it under water for a few hours by mistake once...so it is airtight but still gets condensation.

An airtight light manufactured in a location prone to high humidity will have this phenomenon anytime the window is cooler than the rest of the light. Sometimes, humidity is added to the assembly site by overhead sprayers to cut down on ESD. In the past this has not been apparent but as LED lights run hotter, its becoming more and more common.

What is that yellowish stuff in the torch?

[/IMG]

Well I have noticed when I use 3100mAh 18650 battery on a flashlight that uses two batteries, that they rattle. That is because they are meant to accommodate 3400mAh batteries. Which are a bit thicker and wont rattle. I wrapped the batteries with some electrical tape on each end, and this stopped the batteries frattling.


Sent from my iPhone using Candlepowerforums

My PD35 did this after I clean the lins with water and turn it on turbo mode after indoors.