The dreaded duo-pwm and stepdown

[Ozythemandias]

How did you know there was "terrible PWM"?

I was able to detect it. I'm usually not sensitive to PWM and won't notice it unless I shake the light or use a camera. This light (a Jetbeam keychain light) had it easily noticeable, even without looking for it.

 

[Boris74]

PWM and stepdown. These two issues are just like two car gurus of a hellcat and a Camero talking on break at work. Comparing quarter mile times and torque and cornering Gs they can pull (even though they'll never get close to actually using them specs). Fun to talk about but all they do is drive to work with them or get milk and bread on the weekends. The irony of it is despite all that speed, neither can make it to work on time. Unbeknownst to both of them, they could still make it to work just as late with a Fiesta, even haul that milk and bread on the weekends.

Anyone worrying about stepdown and PWM, it's just water cooler talk to anyone who uses lights. Someone who seeks out a torch because they need one won't turn their nose up because of step down or PWM in total disgust. They'll look at the can I use them lumens, will it survive a drop, is it rain proof? Specs on the box. They aren't concerned with internet chatter about white wall tint tests step downs or PWM. the internet isn't going to change their minds either.

Ill leave these things alone for the tech geeks but I've heard my daily carry user has extremely horrible PWM in moon light only, and is therefore 100% completely unacceptable for any kind of consideration. Only on the Internet........

 

[dmattaponi]

PWM and stepdown. These two issues are just like two car gurus of a hellcat and a Camero talking on break at work. Comparing quarter mile times and torque and cornering Gs they can pull (even though they'll never get close to actually using them specs). Fun to talk about but all they do is drive to work with them or get milk and bread on the weekends. The irony of it is despite all that speed, neither can make it to work on time. Unbeknownst to both of them, they could still make it to work just as late with a Fiesta, even haul that milk and bread on the weekends.

Anyone worrying about stepdown and PWM, it's just water cooler talk to anyone who uses lights. Someone who seeks out a torch because they need one won't turn their nose up because of step down or PWM in total disgust. They'll look at the can I use them lumens, will it survive a drop, is it rain proof? Specs on the box. They aren't concerned with internet chatter about white wall tint tests step downs or PWM. the internet isn't going to change their minds either.

Ill leave these things alone for the tech geeks but I've heard my daily carry user has extremely horrible PWM in moon light only, and is therefore 100% completely unacceptable for any kind of consideration. Only on the Internet........

Hear, hear!

 

[Woods Walker]

IMHO the step down is kinda like the turbo modes of old. If yea want that very bright (within context of the light) which is really beyond the gear item to sustain what is dreaded about an additional feature? Maybe user misunderstanding or in some cases tricky marketing creating unrealistic expectations. As for PWM I am sensitive to it much like humming lights. Then again these are classic first world problems. If these are what classifies as a "dreaded duo" then life is really good so be thankful.

 

[staticx57]

Is the OP (Tom) referring to actual step down of high mode or talking about lights that have the stupid turbo mode?

I will not buy any lights with a turbo mode. I thought this is what Tom was talking about initially when he mentioned having a claimed super high output then a step down to nearly half of the initial output.
This to me definitely sound like a light with a turbo mode. I think these lights are about worthless and I would prefer a light that can handle its high output rating. If a light is rated at 800 lumen for 30-60 seconds then drops to a sustained 400 lumen output; I'd rather just buy a 400 lumen light that could actually handle it. I'm even ok with the gradual step down of the HDS rotary. Just my opinion and i was unclear on what he was asking about on the step down part

You see I just do not understand this point of view? Is it the addition of a separate mode you must cycle through? Is it a psychological thing where your old high mode of 400 lumens is now relegated to medium mode status? As you say, both handle 400 just fine.

 

[ven]

Personally turbo mode so to speak is a bonus mode, use for short blasts and WOW moments(yep still never grows old lighting up stuff with 1000's of lumens). Now some lights(x40vn triple quad, rc40vn to name just 2) will run at max(5000 ish and near 8000 respectively )pretty much indefinite or till cell voltage wont allow. What is more important for me is the modes, amount of and their levels. I know pretty much 200lm will more than cover my uses in work for an example. So what matters to me is a level near or around that and how long i can get before a cell swap. I also do find a high level useful for short blasts, maybe roof void where i want to light up an area for a few seconds, then settle on a lower level to be sustained for a duration(maybe 30m or so).

Boundaries are forever being pushed which imo is great! It creates competition, which brings more choices(colour temps/LED's etc etc) . This brings better efficiency , be it driver, lower vf LED's........... The way i see it, yes i dont actually need 10,000lm for anything, but its better to have and not need ,than to need and not have:naughty:

But not just 10,000lm, this offers 500lm output for a very long time(power outage, lost in a forest................what ever the reason you may need a decent output for over a day! 24+hrs of a very useful 500lm output, ample to light a room well, ample for most tasks..................for a full day! (or several full nights more to the point). I like my 1000lm single 18650 lights(generally) due to offering a good output, decent run times in lower outputs. That initial turbo level(just example) of 1000lm may last a few mins, before a few step downs start, you may end up running(still very useful) 400lm for an hour or so. Now with the larger light(10,000lm example still), you can have your 1000lm for maybe 16hrs..............thats a lot of time and still a lot of output. No run time issues, no heat issues..............

Just my opinion, i know many wont agree but turbo modes are not always a bad thing imo. Its the other modes/levels/run times they provide that are important(the rest is a nice bonus, bragging rights,WOW factor).

 

[INFRNL]

You see I just do not understand this point of view? Is it the addition of a separate mode you must cycle through? Is it a psychological thing where your old high mode of 400 lumens is now relegated to medium mode status? As you say, both handle 400 just fine.

As the op stated, he needs a light that can put out a certain amount of light for a good amount of time and a limited turbo mode would not be good or could be very dangerous. Having an extra mode to cycle through has nothing to do with it for me, it is the fact that I do not see a point in having a mode that can only be used for a very very limited time (which is typically around 60-90 seconds from what i recall)

A person that needs a lot of output is usually for good reason and needs that amount of light just as they would need the sustained light from the other modes. If a person only needs it for short busts, then it would be ok but this is not the case with the op or my use. If a 400 lumen light is not enough for me for a given night and I need let's say 800-1000 lumen for an hour, then a light with turbo mode will not work. As woodswalker said, this turbo mode is just a marketing scheme in my opinion. To me it's pretty obvious that if a person is looking for an 800-1000 lumen light, there is good reason they need this amount of light. They don't need it for a minute at a time.

What if you are doing search and rescue....hey hold on I have to wait to reset my light or let it cool down before i can continue to help search. This is just not going to fly. I hope this answers your questions or helps you better understand my thoughts. Sometimes i am not good at explaining myself, so i hope this is good enough.

I guess i shouldn't say I would never buy a light with turbo mode, but it would not be my first choice or choice wouldn't be because of the turbo mode. If I really liked everything about a light that happened to have a turbo mode, I probably wouldn't turn it down. But currently my lights do not have this feature.

 

[Keitho]

I will not buy any lights with a turbo mode. ... I think these lights are about worthless

Wow. I'd agree that some lights could use a UI improvement, that would give the user a chance to customize modes and not ever have to deal with a turbo mode or any other mode that they consider "worthless" (for example, I don't have much use for sub-lumen modes, and eliminate them from a light's mode rotation when I have the chance).

As a single example used for illustration...the newer Zebralight UI allows the user to program whatever level they want to the different modes, including even making it essentially a "single mode" light if they want. For someone to label such a light, with a completely configurable UI, predictable runtimes, and efficient temperature regulation as "worthless" sounds a bit extreme, just because a few of the many choices are a "turbo" mode.

 

[jon_slider]

I did believe that the step down phenomena affected only lights that offered a 'turbo' mode and that the highest output would be sustained for whatever the listed time period was,

Check reviews for runtime graphs

Few lights have constant flat regulation. Yes most sales specs show runtime for the starting brightness only, the ending brightness can be just 10% of the starting brightness (and still be within the ANSI rules, scroll down to "runtime" for examples)

here is the actual rule:
Runtime
The amount of continuous runtime (in minutes) until the light output drops to 10% of its original value (measured 30 seconds after turning the light on).

This is an example of regulated and unregulated

Acebeam K60

there is a review here

 

[INFRNL]

Wow. I'd agree that some lights could use a UI improvement, that would give the user a chance to customize modes and not ever have to deal with a turbo mode or any other mode that they consider "worthless" (for example, I don't have much use for sub-lumen modes, and eliminate them from a light's mode rotation when I have the chance).

As a single example used for illustration...the newer Zebralight UI allows the user to program whatever level they want to the different modes, including even making it essentially a "single mode" light if they want. For someone to label such a light, with a completely configurable UI, predictable runtimes, and efficient temperature regulation as "worthless" sounds a bit extreme, just because a few of the many choices are a "turbo" mode.

Maybe I should have worded my statement a bit better. Also I actually have a zebralight and like it a lot. The new ui is definitely way better. I do not use this light much anymore but i do not recall it having a "turbo mode" though. I know they have a fairly quick initial drop from what I remember it is nothing like the relative "turbo mode" losing most of it's output. Actually I am almost certain that my zebralight doesn't do this from a runtime test I did in the past between 3 different cells.

But either way for my use and from what i believe the op is looking for, a light with turbo mode is not a good fit. I'm sure it's great for others and that is great for them, just not for my use.

 

[staticx57]

Check reviews for runtime graphs

Few lights have constant flat regulation

This is an example of regulated and unregulated

Regulation and a turbo mode really aren't related. Turbo mode for say a aaa light might be 250 lumens but for another light it could be regulation.

Maybe I should have worded my statement a bit better. Also I actually have a zebralight and like it a lot. The new ui is definitely way better. I do not use this light much anymore but i do not recall it having a "turbo mode" though. I know they have a fairly quick initial drop from what I remember it is nothing like the relative "turbo mode" losing most of it's output. Actually I am almost certain that my zebralight doesn't do this from a runtime test I did in the past between 3 different cells.

But either way for my use and from what i believe the op is looking for, a light with turbo mode is not a good fit. I'm sure it's great for others and that is great for them, just not for my use.

Is having to skip over a turbo mode that much of a hinderance you wouldn't even consider a light? Seems extreme

 

[jon_slider]

... step down ... turbo modes ...sustain ...tricky marketing ... life is really good so be thankful.

lots of variables, add Thermal Regulation to the list
I agree with your conclusion

here is a thread that praises the Acebeam K60 that the OP is interested in, and discusses other "search and rescue" light options.

 

[INFRNL]

Is having to skip over a turbo mode that much of a hinderence you wouldn't even consider a light? Seems extreme

I originally was posting because i was unclear on what the OP was asking and I stated my opinion on the turbo feature. OP answered in his next post. I feel that my discussion with you and Keith is cluttering this thread with opinions that are not anymore directly related to help the OP.
Here is another statement I posted in relation to your comment: "I guess i shouldn't say I would never buy a light with turbo mode, but it would not be my first choice or choice wouldn't be because of the turbo mode. If I really liked everything about a light that happened to have a turbo mode, I probably wouldn't turn it down. But currently my lights do not have this feature."

This will be the last I post of this: I have several lights that range from 200-600 without turbo or step down that fit most of my needs. I also have a few that range from 800-1400 without turbo or step down (and can run for 1-2 hrs or so at these levels). These all fit my needs depending on the situation. If I use a light that has 800 lumen for 1 minute then 400 for 1 hr, this will not fit my needs in certain situations.
As stated before and above, If I happened to buy a new light and it had everything I wanted and had turbo, sure i would buy it. Fortunately at this point I have over 20 lights still after thinning out the herd so i will not need a new light for many years. I am also drawn to certain lights which just happen to not use this feature. I know exactly what i want from my lights, so my interests are very limited.

Everyone has their opinions and I stated some of mine. If you feel these opinions are extreme, that is your opinion. As also stated before and in the case of the OP, a light where the turbo only lasts for a minute or so then drops nearly in half will not be a good option for that certain task/purpose, but definitely doesn't mean that it wouldn't be good for more general use tasks.

@ Tom, I apologize for this and hope that you find what you are after

 

[ssanasisredna]

I was able to detect it. I'm usually not sensitive to PWM and won't notice it unless I shake the light or use a camera. This light (a Jetbeam keychain light) had it easily noticeable, even without looking for it.

... and I can detect flicker where most people can't because I know what to look for, not to mention compression and other artifacts in video playback. For the most part, that barely impacts the usage of the light or viewing of the movie .. unless the movie is terrible and/or the light is not bright enough .. i.e. I am starting to nit-pick.

 

[tom-]

INFRNL, thank you; deeply appreciate your input and all others-have learned a great deal and with some luck pretty soon I will have the topics figured out.

As for the 'sub topics' to me they are great, more info-more smarts.

 

[jon_slider]

As for the 'sub topics' to me they are great, more info-more smarts.

good attitude!

another variable to be aware of is that LiIon, especially multi cell LiIon, has inherent risks
see what you can learn from this thread: Should-I-be-scared-my-Acebeam-K70-might-explode

I would not give a multi LiIon cell light to a newbie unfamiliar with LiIon safe handling practices.