Does dedoming have any effect when emiter (say LH351D) is coupled with a TIR optic? Say I dedomed LH351D in my Skilhunt H04… what would happen?
Asking for a friend 
If you’re comparing the domed LED to the sliced/dedomed emitter in the same TIR, you would still get increased throw and decreased duv, as well as warmer tint. You would also get decreased lumen output.
TIRs are super useful for blending an emitter’s output (certain Cree emitters, like XP-G3, have an awful tint variation from hotspot to spill in a reflector, and a TIR evens that out quite a bit) or for getting certain specific beam shapes. On the whole, they’re not going to change an LED’s tint - this is best demonstrated by something that has consistent tint in a reflector already, and comparing it to a TIR. Luxeon V or XPL-Hi come to mind. What’s neat about a TIR, especially something like a 60 degree pebbled TIR, is you can throw in emitters that have much less desirable tint-rainbows in a reflector and have everything come out nice.
Can same be achived by swaping TIR with different degree one? For instance, I’d like more throw from my headlamp, instead od dedoming my emitter could I put a 20* TIR instead of 60*. Do they work like that?
Thank you for taking time to explain it in noob terms.
Yes, a narrower angle will give more throw.
Can a driver be checked for output voltage without a led hooked to it ?
It depends on the driver. For instance, a FET based driver has battery power going directly to the LED and then the negative side of the LED goes to the driver and it is what controls the current.
You should be able to hook up power to a boost driver and measure the voltage output although it may not be super accurate since there’s no load.
I don’t know a whole lot about Boost, Buck and regulated drivers so I can’t really say for sure.
So what specific driver are you referring to?
It is working now, MT07 Buffalo that fried a led a few weeks ago. I will get you a full update if I get time tonight, busy now. Thanks for helping again. 
Cool. That light has one of those wierd regulated driver designs I’m not familiar with so I’d be no help. 
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It is fixed, What did you mod today? .
I removed the burnt led and it was re-flowed OK. I had wanted to check the driver voltage before risking another led. So that not an option, we hooked it up and turned it on. It fired up with no problems, so the burnt led is still a mystery. Thanks again for your help Jason !!
.
"EDIT: No it does not have to be about flashlights at all"
Ok, here goes: Why is it that human beings are designed to feel comfortable in such a tiny temperature range? A 50 degree Fahrenheit temperature range ( 27.8 Centigrade degree range ) is so tiny in the physical world, yet 40 degrees F room air temperature feels so cold and 90 degrees F room air temperature feels so hot. Why can't I feel ok/fine with a much wider ambient room air temperature, even if the temperature is within 38 to 93 degrees F? Normal people complain if room air temperature is below 66 or above 78. I feel comfortable with room air temperature anywhere from 72 to 74. Why wasn't my mind and body designed to feel ok/fine with real world temperature range?
I would say your mind and body IS designed to feel ok/fine with real world temperature range. It seems to match pretty well with the temperatures of the planet. At least we are warm blooded and can survive extreme temp swings.
My theory: We feel uncomfortable/pain/anxiety to react on a given situation. Clearly, above a certain temperature our DNA denaturates, so that is a valid concern. Below a certain temperature we’re going into energy saving mode, unable to defend ourselfs against potential enemies. Takes too much time to warm up, or, in constant alert mode, consumes too much energy. So we seek company or a warm place when it’s cold. But our body needs to notify us about the necessities.
When we were formed, we had to make sure to survive and being able to hunt. And all we have is that tiny DNA fibre that has formed in the oceans and limit our abilities to adapt.
Here goes my “there are no stupid questions”, question:
If I wanted to use the convoy 4x18a for a host for the sbt90.2, is there anything that needs to be done to the driver? Does anyone know what type of driver is in the 4x18a? Ideallly, does a dd turbo work best for sbt90, to get mot out of led on turbo?
Quick look at the 4x18a shows that uses the xhp 70.2. This is a 6 / 12 volt LED. The sbt 90.2 is a 3 volt LED. So in order to run it you need to install a 3 volt driver plus the work involved in mounting and centering the LED.
The stock driver must be a Boost design. It’s not a common driver layout due to the large battery contact ring. You’d need a driver similar to the Q8 (which happens to be a DD FET driver and should work well with that led). Most likely you’d loose the built in charging.
As a rule
man’s a fool.
When it’s hot
he wants it cool.
When it’s cool
he wants it hot.
Always wants it
what it’s not.
I would accept that as an axiom.
Jasonww- thank you so much for this info. I appreciate the guidance towards an appropriate driver as well. Are you saying that the 4x18a must be a boost design, and that’s not common? Or are you saying that a boost design is needed for the sbt90? I’m assuming you said that the 4x18a is a boost design considering the 6/12 volt led … thanks !
It’s dendroaxonic when it’s hot, and axodendritic when it’s cold.
I miss aXXo.
I can see the battery configuration in the 4x18a is 3v. The LED that it’s using requires either 6 or 12 volts. The only way to get to higher voltages to use a boost driver. Boost drivers tend to be more complicated so they cost more and they’re not as common. They’ve only really started to hit the scene in the last year or two. Also note that Max output for the 4x18a is 5 amp. That’s also very realistic for a boost driver to do.
The SBT90.2 is a 3 volt led. A decent FET driver should push it to over 20 amps.
You would probably need to talk to someone like Lexel about having a driver made to fit the 4x18a. He may have an existing design that can be modified to fit or else he may need to design a new one from scratch. He’s not going to do that unless you can sell enough to make it worth his while, though. Not completely from scratch, he already has the electronics worked out, its just a matter of getting a pcb with the correct size and shape.
A potential complication could be if the switch is soldered onto the driver. If the switch is separate and it’s connected to the driver with wires then it shouldn’t be any problem. Do you have a 4x18A or have seen the driver?