Right Amount of Light?

I (and some others) have spoken about the "right amount" of light.

What is this?

- and is there one light level that's the right amount of light?

see this thread for some previous discussion -
Dorcy 1AAA Outdoors

I do realize this is very dependent on the individual, and what we are used to, or adapted to.

So it would seem pretty obvious to me that the second question about a single light being suitable is not possible.

I EDC a couple of lights and they seem to suit me for most purposes I put lights to -

Now is that because I have adapted to those lights?
or is the EDC because those light levels suit me?

Possibly a bit of both?

In the earlier days of LEDs (and that's not so long ago) when the general (LED) light level for a pocklet LED was in the class of Photons, Inovas, ArcAAA, Ultras and Dorcy 1AAAs - although from my citing, it would seem that we had a great deal of choice - all those lights were about the same ballpark level - of course, some may have been brighter - but not enough to make a real practical difference - at least to me.....

More advancements in LEDs meant that we are now getting much brighter LEDs in the form of Luxeons - 1 watt and 3 watts are now pretty commonplace, and getting more affordable.

I have now acquired more of those, so has my requirements for light levels correspondingly increased with the more affordable and more easily available increase in Lumens?

Not really - I find that the Luxeons of this world are much better for longer ranges - but not as suitable for my closer task usage.

For example I still find the ArcAAA/Dorcy 1AAA class of white LEDs a little bit too bright for reading (black print on white paper) in a dark environment - they seem to affect whatever dark adaption I have acquired (not true scotopic night vision) - not badly, but I definitely notice it - with a choice, I would use something not quite as dazzling for the task.

So I've tried to quantify this with a little ad-hoc experiement -

I am not too sure if it has any scientific meaningfulness - but here goes -

I set a sheet of printed paper lit with a regular 60watt soft-white bulb in a table lamp approx 3 feet away. The printing was 12 pt. Times New Roman (Western) font from my laser printer.


Measured the distance where I could just comfortably read the printing - for me, this was approx 6 feet.

Darkened the room. Then stood at the same distance and used various flashlgihts to see if I could still read the same printing.



These were of pretty wide range of brightness


Note: I am at 6 feet away from the paper - any variance in distances discussed are the distance of the Lights from the paper.

Photon 2 Yellow - my EDC close task light - I could NOT read at 6 ft away - but if I extended my arm to move the light closer I could just read with the Photon 2 Yellow at about 3.5 ft away (I am still at 6feet)

Dorcy 1AAA - a close call, maybe I just could NOT read from 6 ft - but extending the light a little distance - perhaps about 5 ft away from the paper I was able to read well.

eternaLight Ergo 3 Red/White option - with only 2x White LEDs - the 66% level is what I normally find the most useful - and I could read comfortably from 6 feet away holding the light normally (therefore also about 6ft away)

MJLED (#2) in MiniMag 2AA - this definitely was brighter still and the printing was very legible - to the point where I would say it may hvae been clearer than with the regular 60watt soft-white bulb.

S1801 1watt Luxeon 1x CR123 - brighter still and almost to the point of being too bright at 6ft - of course my eyes can adapt to the level and it was not so dazzling that I found it uncomfortable - but I know that it definitely affects any dark adaption my eyes have acquired (as does the MJLED - just less so....)

So to me probably the ideal general purpose light level for my typical tasks is the Dorcy 1AAA or eternaLight Ergo 3 R/W option on 66% level.

But with the caveat for normal handheld reading I still prefer the Photon 2 Yellow, as it seems to affect my dark adaption less........

Again going the other way for the ability of our eyes to accomodate different light levels (ie: dynamic range) I have actually walked outdoors in the unlit countryside with just a Photon Yellow - probably not recommended as the only or ideal light - but I managed.

Comments? Suggestions?

I agree, That's why I have several lights for different purposes! I don't think there is one do all. If it does all light levels, then it usualy isn't pocketable. I have a tri-LuxIII mag that lights up the WHOLE back yard very easily, as well as the whole tops of tree's. That's for lighting up a large area, of if used indoors, I aim it at the ceiling unless I would be doing a building search.

For close range my ArcAAA works well and also works good in pure dark situations for getting around or when I don't want to mess up my night vision.

My Streamlight Jr Lux is good for working close-med range when I need bright light for reparing stuff. And it works pretty good for getting around in the yard. But doesn't light the whole sucker up like the mag! /ubbthreads/images/graemlins/smile.gif

There is no signle right light for everything. If there was, this forum wouldn't exist! /ubbthreads/images/graemlins/ooo.gif

My QIII is almost too bright for close-up work, so I keep a few Dorcy 2-AAs scattered around the house. I tried a 7-LED headlamp for awhile (working in dark equipment areas) but it didn't have enough throw for seeing far away, so I also bought a 1-watt Luxeon headlamp for that purpose. I have a 3-C M*g with an Epieon 1W for power blackouts and general use. I keep one in the car since it doubles as a long-running, fairly indestructible light and a baton if I need it!

My Tri-Lux mag stays in the house or with me to my car. The SL JR Lux stays in my car. And my ArcAAA is on my keychain. /ubbthreads/images/graemlins/wink.gif
You don't have any monster output LED lights? I tell you tri-lux w/20mm reflectors is awesome! great bright wide beam! and side spill bright enough to light up the yard!!

Thanks for the responses.

I remembered I have done something like this in trying to figure out how bright the hotspots of our flashlights were -
in comparison to known light sources like bright sunlight and printed paper lit by a 60watt soft-white bulb -
that post may also contribute to the discussion here -

Just how Bright are our Flashlights? Compared to..

Vincent, Since you stated luxeons are more for throw and too bright close up, have you tried anything like a McFlood or wider beamed optics? I like the novelty of throw and seeing how bright you can have a flashlight, but in all reality flood or wider beam is so much more usefull. Luxeons can have a nice low level of light, but light up the whole rooom!!! Very nice.

Of course you can have wide beam that lights up the yard and is super bright, just pump more lumens in. (tri-lux).

I wonder if the newer luxeons Lux(IV)? will be bright as 1W at 3v dd? If so they may be a lot more efficient for a long running small low power light...

[ QUOTE ]
IsaacHayes said: Vincent, Since you stated luxeons are more for throw and too bright close up, have you tried anything like a McFlood or wider beamed optics? I like the novelty of throw and seeing how bright you can have a flashlight, but in all reality flood or wider beam is so much more usefull. Luxeons can have a nice low level of light, but light up the whole rooom!!! Very nice.

[/ QUOTE ]
/ubbthreads/images/graemlins/grin.gif As soon as I read your suggestion I tried to turn one of my S1801 1watt Luxeon into a "flood"......

well, OK more diffused....

the "cheapo" way


Yes, I strategically stuck some Scotch Magic Tape on the lens - with the resultant more diffused "flood" like light -


The light became also noticably dimmer with this elongated hotspot - this is due to the Scotch Magic Tape being matte by using longitudenal stripes/lines.

I think it was not quite as harsh on the eyes reading on white paper, because the light was dimmer and perhaps because it was more diffused - but it was really still too bright.

Remember this light's hotspot at 14" is about the same intensity as bright sunlight at about 3PM in March on a cloudless day in Georgia. I definitely needed sunglasses to prevent dazzle. So although my eyes can accomodate it - it is not the most comfortable light level for handheld reading....... even when diffused/flooded.

I have been reading at night with LED lights. I have 2 headlamps I have used that work differently but fairly well. One had 12 26k LEDs and saturates the page with so much light and spill it is like using a 100 watt bulb. The other is a energizer 2in1 headlamp with 2 lensed white LEDs that make a soft even ball of light that covers 3/4 of the page with even off white color of light. I tried to use a dorcy AAA but found I had to keep moving it around as I read or use a second light to overlap. I have a 3LED cheap walmart clip light I bypassed the resistors on and use nimh with it that works ok. I have been considering making a CCFL reading light on a flexible arm that sits above me with a switch sitting next to the desk by my bed.

Another idea was to use about 24 LEDs driven perhaps at 15ma each on an arm hooked to a walwart.

[ QUOTE ]
Lynx_Arc said:
I have been reading at night with LED lights. I have 2 headlamps I have used that work differently but fairly well. One had 12 26k LEDs and saturates the page with so much light and spill it is like using a 100 watt bulb. The other is a energizer 2in1 headlamp with 2 lensed white LEDs that make a soft even ball of light that covers 3/4 of the page with even off white color of light.

[/ QUOTE ]
Interesting - thanks for that input.

I really like the Energizer LED Head Beam -

So I repeated the same ad-hoc experiment - it was just about the right level of light at my marked 6feet to read that same printed sheet. As a control/check I also repeated the Dorcy 1AAA and still had to move the light closer (to about 5ft) to read as well.

So for normal reading handheld literature /ubbthreads/images/graemlins/grin.gif I would find this Energizer LED Head Beam a bit too bright - as evidenced by the after images I got when I turned the light off.

I just did the intensity comparison experiment,
and to get about equal light intensity as a 60watt soft-white bulb table lamp set at 3 feet away from the paper surface
- this Energizer LED Head Beam needed to be about 7.5 feet away - which is not possible for me, if used as a headlamp.

The fact that you find a head lamp with 12x 26Kmcd LEDs comfortable for reading (like you said "it is like using a 100 watt bulb") at only about 10-12" away - only goes to show how wide the dynamic range of our eyes are, and the very different levels of light that we find comfortable for reading. I know that would definitely dazzle me - since I already just found the Energizer LED Head Beam used normally as a headlamp - a bit too bright for my comfortable reading.

for your convenience here are my intensity comparison with "known" light sources - using the hotspots of the flashlights - extracted from this post -

Just how Bright are our Flashlights? Compared to..

Compared to good bright Sunlight ~3PM EST March/10/2005 - Atlanta - bright sunny, cloudless -
ArcAAA ~ 3"
MJLED ~ 10"
S1801 (1w Luxeon) ~ 14"
MXDL (3w luxeon copy) ~15"
Streamlight Scorpion (xenon) ~36"

Compared to table lamp 60-watt soft-white bulb at 3 feet away -
ArcAAA ~7.5ft
MJLED ~19ft
S1801 (1w Luxeon) ~26ft
MXDL (3w lux-copy) ~26ft
Scorpion (xenon) ~36ft (+?)

I hope I'm not just talking to myself... /ubbthreads/images/graemlins/blush.gif
But I find this subject fascinating.

Thinking about comfortable reading light levels, and the fact I find the Dorcy 1AAA a bit too bright - I decided to try the diffusion trick with one to see if it improved the reading useablity of the Dorcy 1AAA for me.

quick simple and cheapo way of diffusing the light by use of some Scotch Magic Tape (matte)

With this simple tape in place it was much nicer to read with - for me it was about ideal at about 18" away - eg: using it as a "mouth light" - because of the smoother beam and probably lower light intensity.

In comparison under my normal living room reading light level held at about 18" away from the paper, it was just a bit brighter.

Or taking my reading matter to the window - it's cloudy dull today - the light by the window is what i consider good for seeing fine detail - the diffused Dorcy 1AAA light level was about the same when held about 5-6" away from the paper surface - like normal handheld reading.

Doing my reading limit test I'm at 6 feet away, the diffused Dorcy needed to be about 3.5feet away for me to be able to just read the 12pt font.

Beamshots compared to regular Dorcy 1AAA


Control beamshots of the two Dorcy 1AAA as-is -


Just a quick comment about the step-up semi-regulated circuitry of the Dorcy 1AAA - I am VERY impressed with this cheap flashlight - because that is the original AAA battery in the Dorcy 1AAA (#1) that has been "recharged"/resuscitated using a couple hours on a slow (C/10?) charger - it is almost as bright as my Dorcy 1AAA (#2) on a fresh battery - please see this thread -

Dorcy 1AAA Battery Life

TNC N-cell puts out just right amount of light for close up work.

stk ARC LS puts out just right amount of light for most chores.

The Lionheart has about 60 different levels of light intensity ranging from very dim to very bright.

These can be scrolled up or down effortlessly by pressing the button midway in the body momentarily and then pressing it once again and holding for a few seconds. It gives the impression of a continuous gradation rather like a dimmer switch.

I would imagine that you would be able to select a level according to whatever need you had with this. The lowest level would probably be fine for reading.

On the highest level the tops of tall trees can be lit from
100-200 feet away.

I would have thought that this light would satisfy most needs and it is pocketable and takes rechargeable Pila batteries.

Its smaller cousin the Lioncub is even less noticeable from the point of view of EDCing and coming out soon.

I even read some with the red LED on the energizer headlamp. Most of the books I have been reading do not have bright new white paper so saturation is less of an issue with it. You could also put in an extra resistor in the headlamp to reduce the light output... Oh and I have to use reading glasses at times if the light isn't bright enough so that is probably some of why I don't mind brighter reading light.

I believe I must be an exception as I actually find low-level lights the most useful. My dream light is a variable output light that goes from near-off to about two or three times as bright as an Arc AAA. Small size, again as small as a AAA unit would be perfect and run times from 2 hours on high to over a day on low.

I use lights to check on my kids in bed and to get around the house after everyone is asleep without stepping on all the toys scattered about by the aforementioned children. Then there is the backpacking and camping trips where reading in the tent without disturbing my wife is the primary goal.

I think I must be different then most flashaholics, but I do share a love of quality devices.

John

Maybe you should be in line for the 2nd run nano-3?

In the thread Dorcy 1AAA Battery Life Lynx_Arc suggested checking the batteries by taking the tailcap off the Dorcy 1AAA and measuring the current draw.

I used my old Russian analog multimeter (I don't know how accurate it is - as it's old - been banged about and the closest analog scale ranges are 60mA (too low), or 600mA (not enough differentiation)).

But my Dorcy 1AAA (#1) on the resuscitated battery draws 120MA. Dorcy (#2) on fresh(er) battery draws 140mA.

Swapping the batteries around Dorcy 1AAA (#1) on the fresh(er) battery still draws 120mA and Dorcy 1AAA (#2) also still draws 140mA from the resuscitated battery.

However because Lynx_Arc reported drawing 190mA from a fresh battery and nikon reported 350mA(!) my readings seem low - then I realized my "fresh"(er) battery wasn't that fresh - it may have been fresh(er) over 5 months ago when I changed to it - but it probably isn't now.

So I took a fresh battery out of a pack and measured that - it drew 240mA in both Dorcy 1AAAs - but there was a strange effect - the initial reading was about 200-220mA and it moved up to 240mA.

Although the fresh battery does show brighter (not surpisingly) the old resuscitated battery isn't so dim that it was really noticable in isolation - one can quite obviously tell when beams are side-by-side but I could be fooled when viewed separately - well I obviously was /ubbthreads/images/graemlins/blush.gif

New Battery vs. Old Battery


Swapped batteries around -


So I repeated my reading limit test -
standing at 6feet away from the printed paper - using the old resuscitated battery I needed to move the light closer to about 5 feet away to read the print.
With the new battery I thought I could read with the light at 6 feet - but moved it closer and found I did read better - the distance? 5 feet(!)

So although the side-by-side beamshots do show a difference in brightness it doesn't seem to make that much of a practical difference to me - don't forget although the lights and batteries (and the camera) may be consistent -
there may be an inconsistent factor - the observer - me(!) /ubbthreads/images/graemlins/blush.gif

I do know the new battery is brighter, and I am probably able to read just that bit better -
but it is not significant enough for me to want to change that old resuscitated battery ... yet.

Most likely the amount of extra light put out by the extra current flow is less significant than having adequate light being put out in the first place. There is probably a point where you have to ramp up the light output a lot to get a noticable increase in light, perhaps in the range of overdriving the LED in the light.

good thread!

hotspot is not everything. putting a correct amount of light for closeup work is where optics excell.

a nicely tuned NX-05 optic or NX-01 optic will put out a very useful beam pattern.

most famous example is Larry's tuned optic using a turned down NX-05 coupled with clear fluid, mated to mineral glass lens. Produces a "focused flood".

closest you can get to that beam is with a tuned NX-05 optic in Firefly or a tuned NX-05 in top secret LSH-P proto /ubbthreads/images/graemlins/icon15.gif

The dorcy circuit is good for draining batteries. If I can ever get mine apart I plan on trying a 26k LED in it. If they ever sold the circuit for $3 each I bet CPF'ers would buy em all up.