QTC light owners, how do you like this for EDC use?

So far my favorite EDC lights have always used fixed brightness levels, which I prefer because I can expect exactly how much light I will get and avoid blinding myself. I have a few "infinitely adjustable" lights as well but find they get less use as an EDC light, where speed and simplicity of getting to the desired level takes precedence.

Now QTC seems like it would be very intuitive and extremely simple to get ~roughly~ the amount of light you need without extra effort, but I've not tried one yet. So what do you guys who have tried these lights think? How do you like them for an EDC light?

I really like my peak logan with qtc but Ive decided a mclicky is better for everyday carry. I love having it around for waking up in middle of night and using very low lumens but it is kind of annoying when you just want light NOW.

In my experience the QTC material is a bit temperamental.
All of my experiences are from an Eiger twisty QTC.

While it is possible to get a really low-low on a QTC light it usually requires a few tries at it going from brighter-than-you-want to dim back-and-forth until you get it where you want. Even then, when you let go of the head the light could change brightness.
QTC lights are fun to play around with but don't really expect precision control.

My current EDC is an Eiger 10180 QTC :twothumbs

Yep, don't expect "precision control"

Hm, that getting up in the middle of the night scenario is precisely why I like having a direct access moon mode. I expect the low output to be slightly less convenient to access than high, but I do not want to have to step through higher outputs to get to low. I'm willing to be careful when selecting a low output mode, since I'm consciously trying not to blind myself. High output should be easy to get to in a panic, so QTC with a momentary clicky seems like it would work well.

I really like Thrunite's two-step twisty UI, which is extremely intuitive to access either mode, I just wish it had a more reliable design. I'm of the impression QTC is like a deluxe, infinitely variable version of the Thrunite UI from watching youtube videos of it.

Qtc is nice but very finicky. I prefer control ring lights like Sunwayman or Jetbeam.

I like qtc for my old arc aaa etc. Tested some on a malkoff with sucsess, but a light with modes or a control ring is better.

bottom line, qtc works. it might flicker a bit or drift from static position, but you
can dial up or down the lumens with far greater 'steps' than the current control ring lights

of the qtc lights i have used (peak v1 and v2 and kuku's DD series and original Quantum) Kuku newest Quantum with the
QTC at the led side, is the smoothest of all

the only drawback (it is a minor thing) is when turning off the light, give an extra half-twist to make sure the
qtc is really off. it can be still on at .001 lumens and you won't know until your eyes are totally dark adjusted
and you can barely tell it is on...in that mode, however, it would take >week to drain a battery

it is nice to have a sub lumen edc for dark adapted eyes though...no need to kill night vision just
to find something in the dark if your eyes are already adjusted or you don't want to wake up all the way
just to fumble in the dark...

127.0.0.1 said:

bottom line, qtc works. it might flicker a bit or drift from static position, but you
can dial up or down the lumens with far greater 'steps' than the current control ring lights

of the qtc lights i have used (peak v1 and v2 and kuku's DD series and original Quantum) Kuku newest Quantum with the
QTC at the led side, is the smoothest of all

the only drawback (it is a minor thing) is when turning off the light, give an extra half-twist to make sure the
qtc is really off. it can be still on at .001 lumens and you won't know until your eyes are totally dark adjusted
and you can barely tell it is on...in that mode, however, it would take >week to drain a battery

it is nice to have a sub lumen edc for dark adapted eyes though...no need to kill night vision just
to find something in the dark if your eyes are already adjusted or you don't want to wake up all the way
just to fumble in the dark...

Click to expand...

I want one.

jorn said:

I like qtc for my old arc aaa etc. Tested some on a malkoff with sucsess, but a light with modes or a control ring is better.

Click to expand...

Nice idea! Did you just put the Peak qtc into the bottom of the Arc?

QTC in my jil light works very smooth no jittery flickering. perfect.

Kamerat said:

Nice idea! Did you just put the Peak qtc into the bottom of the Arc?

Click to expand...

No, I just stuffed it in the foam at the head. It's not a peak pill. Just some qtc squares that I bougt from somewhere in uk. Works like a charm, stays in there and wont fall out.

The only QTC light I have is the SS Peak Eiger and it is horrible. It kept flickering on any given output and sometimes when on low it would shoot up to somewhere near medium output before declining back down. Irritating really.

I've never had that kind of serious problem with any of my Peak Eigers.

creyc said:

Hm, that getting up in the middle of the night scenario is precisely why I like having a direct access moon mode. I expect the low output to be slightly less convenient to access than high, but I do not want to have to step through higher outputs to get to low.

Click to expand...

Then the current QTC technology isn't for you. I have three Peak QTC lights (one earlier version and two with the second generation pills) and my experience has been effectively the same with all of them. The QTC dimming works like a dream initially, but after a few months of use, the reliability, in terms of ease of adjustment, decreases significantly.

Getting the really low lows is easy at first - low enough that the LED is barely glowing. After a bit of use though, it gets increasingly difficult to maintain these sub-lumen levels. As well, on the rare occasion that I am able to achieve a nice moon glow, the slightest knock or bump (even something as insignificant as setting the light down on a hard surface) will increase the output substantially. Then there's also the occasional flickering that was mentioned before.

That all said, I love Peak lights and I will continue to order them with the QTC option. Hey, why not? Though the QTC pill's period of maximum effectiveness might be short, the period of partial effectiveness lasts much longer, the upgrade doesn't add much to the price, the pill weighs nothing, it's perfectly efficient, it adds no complexity to the electronics and in the event of a complete failure, the light merely becomes a single mode torch that illuminates at full power. So again, why not?

^ 3 really good points when considering EDC: efficient, does not add complexity to the electronics and in the event of a complete failure, the light becomes a single mode H. QTC is much more efficient than electronics. Magnetic ring controls, in my experience, are particularly inefficient and don't the deliver the expected runtimes on L. The lack of electronics means there is one less thing to fail. If the QTC does fail, the light becomes a single mode H. This is less than ideal on a 101080 and isn't great on a 10440, but it is better than a complete failure.

I second yoyoman's comments.

yoyoman said:

^ 3 really good points when considering EDC: efficient, does not add complexity to the electronics and in the event of a complete failure, the light becomes a single mode H. QTC is much more efficient than electronics. Magnetic ring controls, in my experience, are particularly inefficient and don't the deliver the expected runtimes on L. The lack of electronics means there is one less thing to fail. If the QTC does fail, the becomes a single mode H. This is less than ideal on a 101080 and isn't great on a 10440, but it is better than a complete failure.

Click to expand...

Bronco said:

Getting the really low lows is easy at first - low enough that the LED is barely glowing. After a bit of use though, it gets increasingly difficult to maintain these sub-lumen levels. As well, on the rare occasion that I am able to achieve a nice moon glow, the slightest knock or bump (even something as insignificant as setting the light down on a hard surface) will increase the output substantially. Then there's also the occasional flickering that was mentioned before.

Click to expand...

Great summary and what I've now gathered from reading the Peak threads. I'm a big sub- & low single-digit lumen fan (my most often used modes by far) and was considering the Peak QTC as way to dial in just-the-right-amount-of-light without the efficiency loss of the magnetic rings. Probably not the right right light for me.

I wonder if the new QTC upgrades for the Peak Eigers will help address any of these mentioned issues?

I've also got an RRT-01 on the way to test out the magnetic control ring interface, but ideally I think I'd prefer an Eiger-sized light.

I think or I'm guessing that some people have problems with the QTC because they twist too hard to get H. You can see pictures of people with damaged cells and this is clearly caused by twisting too hard. As the cell drains, output is reduced and you can keep twisting because you don't think you've reached H yet. But you have reached H and are really crunching things inside the body. I mainly use my Peak Eiger Nichia 219 SS 10190 for low light and so I never twist too hard and my QTC has been stable. I don't have problems with flickering or the output suddenly jumping. If you are a sub-lumen, low lumen fan, I think the Peak Eigers are really good. Much more efficient than magnetic ring set ups which means you can get good run time from a 10180 cell. You get a very small light that you can keep on you at all times without really noticing it.

I also have a Large Optic with XP-G2 N in a SS AAA body - momentary switch and no QTC because I mainly use it on H. I recharge the cell when I recognize that it isn't as bright as it was with a fully charged cell.