Low-medium modes & PWM?

I'm a noob to multi-mode lights. Previously I was hesitant to invest in a mid-$$ multi-mode light for fear of reliability issues. Thus far my DX14442 has performed flawlessly, and has changed my viewpoint entirely, I've even dropped it once:twothumbs. If a $13 DX drop in is this reliable heck the higher $$$ ones must be outstanding. Time for me to expand.

I was wondering if you could comment a little on your various lights (headlamps included) low and medium modes and the PWM pulsing for each. If you shine the light at a running water faucet or fan... how severe are the PWM effects? Is it tolerable? or does it look like a nightclub strobe?... or is it completely non-existent. I know this is highly subjective, and I dont expect everyone to agree completely... but thats OK so long as we agree to disagree.:twothumbs

**edit** And if your lights do not use a PWM circuit at all (and avoid the issue all together), please comment on that as well.

thanks in advance

That depends entirely on the PWM frequency (and hence the specific light). Some lights give off a noticeable flicker on low even with nothing moving in the beam. Some lights have the PWM set to several kHz, and you would have to be using it around some high speed turbo machinery to even have a chance to notice it.

And lots of lights don't even use PWM for mode control, so it's a non-issue.

I've never noticed the pwm on my L1T V2.0. I typically use it in the real world on low when I'm out in the woods or the like.

As far as quality/reliability, I never understood why everybody loved fenix so much until I got one. I have the DX 1-mode cree improved (or something like that), which I thought was great (esp. acter upgrading the emitter to a q5). But once I got my hands on a fenix (it was the E1 intitially) I understood. MUCH better switch, gold plaed spring (on the L1T), nicer glass, reflector. Its just a better, more rugged set up.

Buck91 said:

I've never noticed the pwm on my L1T V2.0. I typically use it in the real world on low when I'm out in the woods or the like.

Click to expand...

That's because the L1T v2.0 doesn't use PWM to control the brightness.

Ah ha. That would certainly explain it.

Marduke said:

That's because the L1T v2.0 doesn't use PWM to control the brightness.

Click to expand...

:laughing: That was funny.

It may also depend on the person; some seem to pick up certain frequencies easier than others.

It would take a couple of days for me to comment on just half of my lights I think...
Some of the ones that use PWM and comments directly about PWM...

Proton Pro - definitely a noticeable PWM mildly annoying
Wolf Eyes P7 Sniper - same as above
Jetbeam CLE - PWM is annoying as a middle school orchestra concert
Jetbeam MkIIx - same as above
Jetbeam Jet MK IBS - not noticeable at all
Liteflux 2 SSC - not noticeable at all
Liteflux 3 - same as above
Liteflux 5XT - same as above

It's relatively rare nowadays to find visible PWM effects on high quality lights. All my modern NiteCore, JetBeam, Zebralight and ITP lights use a PWM freq >1kHz, which I can't detect by eye (e.g. using a fan) or by instrument. You would have no way to even know it's there.

It's mainly older lights that had the problem (e.g. earlier JetBeams) - and of course, visible PWM is still common on many of the cheapie deal site lights.

That being said, I don't know about the Fenix L0D or Dereelight DI pills (both were in the visible ~100Hz PWM range on early specimens that I own).

And yes, all other Fenix light are current-controlled, so no PWM. Same is true for most of the Olights and Lumapower lights, so no worries there either.

Whenever I measure it, I give the PWM freq in my reviews and round-ups. Personally, I've always found anything <100 Hz intolerable to my eyes, and 100-200Hz barely acceptable. No worries for anything >300Hz.

Selfbuilt, I beg to differ. The Zebralight H30 I briefly owned had around a 1.5kHz flicker, but it was more of a sine shape than a square shape, though, if you know what I mean. The SL Argo HP also uses 1.5kHz but in the traditional full-on, full-off, etc. square-wave shape, and I notice that flicker when navigating or doing routine tasks. The programmable LiteFlux lights use 7.8kHz, which I definitely can't see, and I think the NDI and D10/EX10 also use a pretty high frequency, as I can't see their flicker either.

Personally, I think I'd want at least 3-4kHz if not higher. You'll just have to experiment and see what works for you.