My new Fenix LD12 gen2 has PWM

So as the title says to my utter surprise my new LD12 Gen2 has PWM. It is a bit strange in that it is fine when I just turn the light on. It is only when I change levels that the PWM shows up and then goes away when I turn the light off and back on. It is present at all levels except high but goes away when I turn it off and back on. My older LD12 R5 is fine, no PWM at all its only the gen 2.

Has anyone else noticed this or do I have a dud?

I don't think Fenix has started using PWM on their lights..

Flashlight Dave said:

So as the title says to my utter surprise my new LD12 Gen2 has PWM. It is a bit strange in that it is fine when I just turn the light on. It is only when I change levels that the PWM shows up and then goes away when I turn the light off and back on. It is present at all levels except high but goes away when I turn it off and back on. My older LD12 R5 is fine, no PWM at all its only the gen 2. Has anyone else noticed this or do I have a dud?

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How are you determining this?

tickled said:

How are you determining this?

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Well a picture is worth a thousand words. I basically did the shake test.

I first saw it here on CPF. I looked for the thread but could not find it but the OP stated that one can detect PWM by shaking the light. When a light with PWM is shaken it isolates the strobe so the PWM effect becomes visible. It is similar to shining the light on a fan.

For example one light with low PWM is the Protac 2L.





The photo below shows the Protac shaken. The PWM is apparent.





Now for the LD12 G2. Here is the light.







As I mentioned in the start of the thread when the light is first turned on low it does not show any PWM.




As one can see the beam is stringy but intact. The light is on the lowest setting. Sorry for the bad photo.

When I cycle through using the side switch the PWM starts up. It is not as slow as the protac but its still present. These are two shots of the same LD12 on the same lowest setting.







I discovered this by accident. I moved the light and saw the PWM effect. So as mentioned at the beginning of the thread I don't know what to make of this. The older R5 version did not do this and I am not sure if all the LD12 G2s are like this or just mine.

Hmmm...

At first I hated pwm, but over time it has grown on me to the point that I consider it a trade off.

Yes it's annoying, but it allows for very white light at low levels.


It doesn't look very noticeable. Is the light whiter on lower levels?


I actually think this makes me more likely to buy a G2 model, since I don't care for the green tint of the low levels on my Q5

I don't think it uses PWM. I have noticed that my LD12 R5 once in a while has a strange mode. It's quite difficult to replicate on demand but once in a while I stumble on it. This mode is around 4 or 5 lumens and has a strobing effect similar to what one might describe as PWM. Once I power off the light and power it back on all is well.

I don't know what causes it but my guess is that light somehow gets stuck cycling between modes at a very high rate. Kind of a mode cycling runaway if you will. I think this is what you're seeing were I to guess Flashlight Dave.

You may want to give your dealer a call and swap out your light if it happens a lot. While I love me LD12R5, my first unit seemed very dim. When I compared it's different modes to a known good flashlight with similar modes it appeared everything was half brightness. I ended up sending it back to the dealer and they sent me a new one with no issues. I love Fenix lights but no one is above sending out a turkey now and again.

Ezeriel said:

Yes it's annoying, but it allows for very white light at low levels.

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I never thought of that but I guess it makes sense. I can't say if it is more white on low but I can say it is white. I have two XP-G2s and both have different tint but neither have green. And you are right it is not really that noticeable.

pinetree89 said:

I have noticed that my LD12 R5 once in a while has a strange mode. It's quite difficult to replicate on demand but once in a while I stumble on it.

It does not seem to be something that happens once in a while but I can do it on demand. The effect takes place after I change modes.

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Have you tried the cellphone test? If you do a close-up of the emitter, you'll get vertical banding in the image with PWM, and the narrower the banding, the faster the PWM frequency. On the left is an Eagletac 2012 D25A-X on moonlight and Quark AAX on the same. Interestingly, my D25A only goes PWM when my NiMh is low.... I consider it to be a "feature" (battery meter).



I've read a lot of people say PWM won't tint shift as much as current regulated lights, but I don't see it. Here's a pix of some of my sub-lumen collection. Top half are all on sub-lumen modes, and the bottom half are all in the 100-125 lumen range. Only one of the lights is PWM on moonlight.

Cell phone test- great idea!

Here is the Protac on low




Here is the Fenix LD12 G2 when I first turn it on. The light is on the 3 lumen low




As one can see no PWM

As I mentioned when I cycle through the levels the PWM shows up. Here is the same 3 lumen low level once I cycle through the side switch.




The PWM is not as bad as the Protac but its there

I don't want in no way to question your method of detecting PWM and in any case thank you for posting this and including pictures.
I find it strange that Fenix resorted to PWM for their new lights, I don't remember any of the old XP-G R5 having PWM.
The best is that you send them a mail and ask if there's supposed to be any PWM at all - they are usually very quick to reply.
If they say there isn't supposed to be any as other suggested I'd contact the retailer and ask for a replacement.

Flashlight Dave, My LD12 G2 seems to act just like you describe yours, cell phone test and all.

I will have to test out my LD12 S2 later to see how it does.

Interesting, but regardless I still love the LD12 G2. The output is so much nicer IMHO then the LD12 S2.

Just an FYI, while you can clearly see the banding in your pix, I have noticed some PWM to go undetected with the camera that far away. It's more reliable when the camera is right up against the flashlight, and the auto focus/exposure can adjust to show the emitter.

reppans said:

Just an FYI, while you can clearly see the banding in your pix, I have noticed some PWM to go undetected with the camera that far away. It's more reliable when the camera is right up against the flashlight, and the auto focus/exposure can adjust to show the emitter.

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Seems that you are right. Here is a pic of the LD12 G2 up close

Only my LD12 G2 displays signs of PWM like Flashlight Dave's. My LD12 S2 does not.
It's something I only notice by doing the test pointed out in this topic and its not something I notice other wise.

Does anybody know if this PWM exists in the new PD32 or LD22 using the xp-g2? Because I have been eyeballing those. Not a big deal probably, but just want to know.

wow. fenix has really gone downhill from the LD10 (actually a pretty decent light)

1) less lumens
2) crappy side button interface
3) cheap circlip holding in the switch assy
4) PWM !!!

well done fenix. congratulations!

Interesting. Sounds like there's a bug in their lights. So when you turn it on at any level, there is no PWM but as soon as you start cycling through the levels, all levels have PWM?

Mr Floppy said:

So when you turn it on at any level, there is no PWM but as soon as you start cycling through the levels, all levels have PWM?

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If PWM is present even at the max level, then I would blame/bless some kind of thermal protection.

Overclocker said:

wow. fenix has really gone downhill from the LD10 (actually a pretty decent light)

1) less lumens
2) crappy side button interface
3) cheap circlip holding in the switch assy
4) PWM !!!

well done fenix. congratulations!

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Referring to quality I had not mentioned that my LD12 G2 had a rather loose tail cap but that might be just the luck of the draw.

[alexandrul said:

If PWM is present even at the max level, then I would blame/bless some kind of thermal protection.

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Does not do it on high and does not do it on low when you click it off and back on. Strange I know.

Overclocker said:

wow. fenix has really gone downhill from the LD10 (actually a pretty decent light)

1) less lumens
2) crappy side button interface
3) cheap circlip holding in the switch assy
4) PWM !!!

well done fenix. congratulations!

Click to expand...

The first Fenix I purchased was a LD10 at a sporting goods store. I returned it because I did not like how the tail cap worked.

When Fenix come out with the side switch I purchased the LD12 S2 and EDC'ed it for months until the LD12 G2 come out.
Like it even better then my S2 version. As for the PWM I don't notice it unless doing the test pointed out here in this topic. Maybe other people will notice the PWM in normal use, but for me I can't notice it.

Less lumens? How the LD12G2 is 125 lumens and from what I read on the LD10 it's 100 lumens max.
Crappy side button interface? Personal choice, unless the switches have been mechanically failing.
Cheap circlip holding in the switch assay? I have no clue what that means. Has it caused some kind of problem with the LD12's?

To each their own. We will never all agree on every flashlight and there will never be the one perfect flashlight. Maybe the reason there are so many flashlight manufactures making so many new models all the time.