The There Are No Stupid Questions Thread

Searched pretty well and coudn’t find this question asked yet:

Whats the purpose of frosting the center of a 3-up or 4-up optic? How does it affect the beam?

Less beam artifacts/smoother beam transitions.

I have a question for those who sand down TIR optics to fit in lights because I sanded mine down to fit into a D10 and it resulted in having a donut hole. How do you guys remedy that or is it now a lost cause?

Hmm, I’ve never heard of that happening. What optic was it, a narrow angle one? I tend to use wide angle ones for close up work. Those usually have a pebble texture finish. You might try raising or lowering the optic to see if that changes the focus.

It was a 60 degree pebbled lens. Similar to this one. . There isn’t a lot of clearance to raise/lower the optic. I wanted to leave the glass lens there since I made the mistake of shaving the diameter a bit too much and is not making a prefect seal in terms of waterproofing.

We have the same mods (I use the glass lens in my D10 also, but no centering ring), but I don’t have a donut hole pattern. You removed the white part, yes?

Maybe your particular optic is the issue. If your in the USA you might try buying this one. A little bit of filing is all it needs and the beam is perfect in my light.

If you’re outside the US and it costs too much to buy from Mountain Electronics, you might just try buying a different brand of optic from AliExpress and see if that fixes the problem.

Yeah I removed the white part, maybe it is the optic. I guess I’ll try to experiment on it since it’s good as broken anyways. Thanks for always answering my questions here JasonWW. Really appreciate it.

Are you both using the same emitter? If an optics behaves well with XM-L2 in particular, it’s often not great with other emitters (in my experience anyway).

I’ve tried it with the stock emitter which is probably an xml2 clone as well as an XPL, nichia 219 and 319. They all gave me a nice smooth pattern.

(EDIT: Oh and the Samsung LH351D as well)

I’ve also fitted these same lenses from MTN E into other lights with good results.

Cool, thanks for that info. I may grab some of those TIRs at some point.

I did not consider the emitter I was using. I’m using an SST20 in mine. Kinda already destroyed it last night sanding it all around making it a frosted optic so I can’t try on another emitter. An undesirable method but it works, no donut hole anymore.

I wonder if it could be that led? It’s smaller than all of the ones that I’ve tried.

It’s either the led or the optic. If ever I try again with a new optic I’ll share my experiences with it.

What can be used to allow mechanical lockout on lights with unnanodized threads?

If my fasttech optics ever show up, I’ll let everyone know how it goes. Currently have the stock XM-L2 (either crap bin or clone, don’t know or honestly care much) in the stock reflector. While it feels like about 50CRI of 7000K, the beam profile is actually pretty good for me. And the output level is honestly just right - I left it on turbo for a while longer last night, and a few parts of the light did get slightly warm, but it’s nothing compared to most of my lights on higher modes. I should grab my SC62 for output comparison to get a good idea of where it’s at, since that’s a cool white XM-L2…

Nothing easy. You can take out the battery, but then you have to store it somehow. That’s not very convenient. Another option is to use a piece of insulating plastic between the battery and tailcap spring to cut power. If the insulator is thin and flexible you can store it in the battery tube for convenience.

If the light is designed a certain way, it’s rather easy: unscrew about a quarter-turn.

The light must use a tail-switch board that insulates the negative end from the battery cap (my Emisar D4 does this). So, the negative path is: Battery ()> spring -> trace near edge of board -> end of battery tube when it screws down fully and contacts the trace. Uh, probably a good example of a non-anodized light that does this is the titanium D4 series.

flightless22 was specifically asking about lights that don’t have anodized threads.

Right, which I was specifically addressing. If the light is designed properly, the current path doesn’t use the tailcap, and all you have to do is lift the battery tube off of the contact board that sits in the bottom of the tailcap. The D4Ti should be an example of this - but I do not own one, and therefore cannot test it. There’s some discussion here but I didn’t find anyone confirming it by testing.

Umm, no. I think it’s safe to say (only he can confirm) he was asking something along the lines of:

“I have a light that doesn’t have anodised threads. Can it be made to physically lock out?”.

Eg, my ’502s don’t have ano threads, and can’t easily be made to lock out.

Short answer is no.

Longer answer is yes, if it doesn’t have a spring on the driver side, but only a small bump/nipple, and can take flattops.

In that case, a thick enough O-ring can be dropped in to physically try to push the cell away from the driver. Only tightening it up would squish it tight enough to make contact. So it basically becomes a twisty with tailswitch.