Do you really use 0.2 lumen?

[joema]

....If the Quark can do .2 lumens, the RA .3 lumen (or as low as .1, I believe) but the SF T1A goes down to 1.0 lumen, how can the T1A go "a bunch lower" than the Quark, etc? Does it go lower than the claimed spec?...

My Ra Clicky outputs 0.07 lumens on the lowest level. Assuming that's correct and using it as a reference with a lux meter, my Surefire T1A is a fraction of that -- the lux meter says 1/80th of 0.07 lumens, which would be 0.000875 lumens. With fully dark adapted eyes you can *still* navigate a small room using that, which shows how non-linear human brightness perception is.

My Photon REX's lowest level is about 1/9th the output of my Ra Clicky's lowest level, which would be about 0.0075 lumens.

My Quark 123 Mini's lowest level is about 17x brighter than the Ra Clicky's lowest level, which would be 1.21 lumens.

 

[Connor]

@joema
You cannot convert lux readings to lumens like that. In fact you cannot convert lux to lumens at all - they are two completely different units measuring different qualities of light.

 

[Bullzeyebill]

My Ra Clicky outputs 0.07 lumens on the lowest level. Assuming that's correct and using it as a reference with a lux meter, my Surefire T1A is a fraction of that -- the lux meter says 1/80th of 0.07 lumens, which would be 0.000875 lumens. With fully dark adapted eyes you can *still* navigate a small room using that, which shows how non-linear human brightness perception is.

My Photon REX's lowest level is about 1/9th the output of my Ra Clicky's lowest level, which would be about 0.0075 lumens.

My Quark 123 Mini's lowest level is about 17x brighter than the Ra Clicky's lowest level, which would be 1.21 lumens.

Are you using ceiling bounce and logging the lux numbers, or a type of lightbox using a light meter. I use bounce with a lux meter comparing to some off my other lights to get approximations of lumens.

Bill

 

[hopkins]

Some people can tell it is easier to negotiate terrain when Jupiter is in the
clear night sky due to its added light to only star light -no moon.

So 0.2 lumen can really be enough, but not all you might want.

 

[joema]

@joema
You cannot convert lux readings to lumens like that. In fact you cannot convert lux to lumens at all - they are two completely different units measuring different qualities of light.

I used a lux meter to measure the known lumen output of a Ra Clicky at 0.07 lumens, and used that lux value as a "standard candle" when measuring other lights. That should have been clear from my previous post.

If the Ra Clicky at 0.07 lumens produces x lux, and another light produces 17x lux under the same measurement conditions, it's roughly 17 * 0.07 lumens, or 1.19 lumens.

The measurement was taken point blank with the light against the lux meter sensor. This reduces any impact of reflector, optic, or beam angle.

No, it's not a NEMA calibrated method, but for our informal purposes here it gives the approximate magnitude of difference.

It's not that different from the "milk carton" lightbox method used by Doug Pribis for many years on flighlightreviews.com. He used a lux meter to measure relative output differences and extrapolated that to an approximate lumen value: http://flashlightreviews.com/features/output_vs_throw.htm#lumens

Of *course* lux and lumen are two different entities. But -- given a *known* lumen output, you can easily extrapolate the *approximate* lumen output of a different light from it's lightbox lux number. Capturing most of the output by pointing the bezel against the light sensor (if covered with a translucent, diffusing filter) is like a mini-lightbox.

 

[dealgrabber2002]

If it is possible and not too much to ask, can someone post a picture of <.02 lumen in actual use in a dark room? I remember reading that someone actually ceiling bouce with such low lumen or navigate a room in total darkness. I don't have such a low low lumen. I am curious.

 

[Burgess]

Keep in mind, your EYES are not like a Camera.


A photo would hardly show a fair representation.


:candle:
_

 

[chanjyj]

Keep in mind, your EYES are not like a Camera.


A photo would hardly show a fair representation.


:candle:
_

If you use a slow shutter (drag shutter, burst the light) it would show a close approximation.

 

[curtis22]

Is there a difference between "really use" and "use"?

I use .2 lumens a lot.

 

[dealgrabber2002]

Is there a difference between "really use" and "use"?

Some can just turn it on and use it for fun. But not necessary use it for real world application.

 

[EZO]

Is there a difference between "really use" and "use"?

I think if you read the original post for this thread you'll understand how dealgrabber2002 meant that question. This thread made me more aware of how we all have different subjective experiences with low light sensitivity.

 

[AILL]

I use the lowest mode of my Novatacs (8 different) every night. One is always sitting on my nightstand and illuminating the roof. Depends which tint I like in the night.
I live in a private street without illumination and my house is close to the forest. Can be VERY DARK here, believe me, you will not see your own hands in the dark if there is no moon shining.

Andreas

 

[dealgrabber2002]

I decided to bring this thread back to life since I've just read a post someone is looking for a light that is lower than .1 lumen. Some like me will ask "you for real?.. what do you do with that less light?" There are some interesting opinions in this thread.

Guys, it's no joke when someone asked that. They really have use for it.

 

[AnotherADDiction]

I am amazed at how I graduated 'down' in light. I went from a D10 to a clicky. I thought that was good until I received my Arnor head from Milky - that low is fantastic. It is amazing how useful it is when the MCE die is just almost glowing. The Quark RGB on moonlight with the red LED is pretty good too.

 

[flatline]

So, when choosing the right amount of light for a job, here are my criteria:

1. the level of light must be sufficient to meet my illumination needs.
2. the level of light must not be enough brighter than the ambient that my eyes need to adjust to it before I can function.
3. the level of light must not be enough brighter than the ambient that my eyes need to adjust to the ambient when I'm done using the light.

With these rules in mind, I hope it's obvious why I treasure the 0.07L output of my HDS Clicky so much. Even the Quark moon mode is too high when I get up in the middle of the night to check on the little man.

--flatline

 

[maro69camaro]

my edc right now ex10 will light my whole room tail standing on low. I really wish it had a lower setting.

 

[PCC]

I bought a Quark 123 Tactical specifically for the moonlight mode that it offers. As a matter of fact, the second setting is set to Low and I never use it. I have a dead CR123a in it that is so drained out that it won't stay lit on Low for more than a few seconds. I bought this light because I needed a light to use in the early mornings when I'm getting ready for work and the 2 lumen low is bright enough to wake my daughter. The 0.8 lumens from the moonlight mode is still brighter than my night-adjusted vision can handle, so, I'm now looking for something with an even lower low.

 

[fisk-king]

I bought a Quark 123 Tactical specifically for the moonlight mode that it offers. As a matter of fact, the second setting is set to Low and I never use it. I have a dead CR123a in it that is so drained out that it won't stay lit on Low for more than a few seconds. I bought this light because I needed a light to use in the early mornings when I'm getting ready for work and the 2 lumen low is bright enough to wake my daughter. The 0.8 lumens from the moonlight mode is still brighter than my night-adjusted vision can handle, so, I'm now looking for something with an even lower low.

IMO, if you are looking for a CR123 light with a very low setting the Surefire T1A (Titan) would be the first to start looking into. Keep in mind they are pretty pricey which is another discussion.

Personally, I only see use for that type of low setting which is late in the morning to navigate around the house or if I was stuck in the jungle/bush and don't want to give my position away to *Charlie*.

 

[L.E.Diode]

use my new sunwayman m10r around the house all the time it has a very low low 4 lumen i think would not want any less

 

[scout24]

My Titans and Titan T1A's have the most usable low level around, IMHO. The other option is the new variable Jetbeam, goes much lower than my Sunwayman V10A, just as low as my Titans. I switch back and forth between them for getting ready for work and "midnight runs" in the house, everything else is too bright for me. A very low cost option is the Photon Freedom Micro coin cell light, only goes to 10lm. or so, but has the same sweet low. Much easier to mouth hold than Titans or Jetbeams. Be sure to get the covert nose, or the sidespill from the emitter will degrade your night vision even at these low levels...