LM31 and LM33 "Warmth" and Low-Level Brightness?

SEMIJim

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Sometimes my wife wakes up and wants to read. In order not to wake me, she uses a flashlight. I'd like to get her something handier than the dime-store 2-D-cell light she's been using. Thing is: She can't tolerate anything PWM'd (either the flicker or the high-frequency noise they sometimes generate will make them unbearable for her), and she can't stand blue-ish tint.

I'm wondering how either the LM31 or LM33 on low would work for her? Do those lights produce a nice, "warm" tint? They're not PWM, right? Is "low" on each bright enough to comfortably read a book by?

TIA,
Jim
 

Gary007

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Not sure about the LM31 and LM33, but, what about a Zerbalight? I also have a Novatac and can read comfortably on it's lowest setting.
 

Grubbster

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They use a resistor for their low mode so there is no flicker. The brightness is probably fine for her to read with, however I would recommend a headlight like the Rayovac 1AA with diffuser or the zebralight.
 

Sgt. LED

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Lm 31 all the way! You just need to get ahold of one. You will be glad that you did, believe me. Other lights are great but I keep going back to my LM 31.
 

SEMIJim

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Gary007, Grubbster,

I doubt she'd want to wear a head-band, but that Zebralight does look interesting.

Gunner12, Sgt. LED,

Can you give me any idea about the colour tint?

Thanks for your comments, everybody.

Jim
 

Gary007

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you don't have to wear a headband, you can just clip the light anywhere.

Gary007, Grubbster,

I doubt she'd want to wear a head-band, but that Zebralight does look interesting.

Gunner12, Sgt. LED,

Can you give me any idea about the colour tint?

Thanks for your comments, everybody.

Jim
 

Gunner12

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I don't have the light(hence "would be fine" from looking at the specs).

It should be tinted yellow because of the lower current. It should be neutral on high.
 

SEMIJim

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Gary007,

Thanks for the suggestion, but, if she's not going to wear the headband, I don't see the point to paying $20 more for the light than what the LM31 or LM33 would cost from BatteryJunction.

Gunner12,

Probably true. Hopefully somebody will be along sooner-or-later to give me a definitive answer, tho.

Thanks to the both of you for your feedback.

Jim
 

BigD64

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I have a 33 on low it has a slightly warm tint. It would be fine for reading at night.
 

ernsanada

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LM301 with Duracell AA Alkaline

LM301Small.jpg


The light is a hair brighter and has a little more side spill then shown in the picture. Like all beam shots they are hard to capture in digital pictures.

LM301001Small.jpg
 

SEMIJim

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BigD64,

Thanks for the feedback.

ernsanada,

Thanks for the comments and the picts. Does look kind of dim-ish for reading. Could just be the difficulty in getting a camera to faithfully render reality, as you note. IIRC, the LM33's "low" is a bit brighter than that of the LM31. Perhaps the LM33 would be the way to go, then?

Jim
 

Mockingbird

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She could use the LM31 on high and just hold it farther away or you can still get the Fenix Civictor (30 lumens) from Lighthound for 28 bucks. I have both lights. Either light will allow you to avoid lithium batteries.
 

worldedit

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I use my Zebralight every night. Lowest setting is just right for reading and its comfortable to wear no matter in which position i read.
 

Luminescent

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Sometimes my wife wakes up and wants to read. In order not to wake me, she uses a flashlight. I'd like to get her something handier than the dime-store 2-D-cell light she's been using. Thing is: She can't tolerate anything PWM'd (either the flicker or the high-frequency noise they sometimes generate will make them unbearable for her), and she can't stand blue-ish tint.

I'm wondering how either the LM31 or LM33 on low would work for her? Do those lights produce a nice, "warm" tint? They're not PWM, right? Is "low" on each bright enough to comfortably read a book by?

TIA,
Jim

No manufacture has a direct hotline to perfect tint heaven, so talking about the 'tint' of one light vs. another is really pretty silly.

Here's a thread with lots of folks who got off tints on big bucks Surefire lights:

https://www.candlepowerforums.com/posts/2248091

Some Surefire lights cost more than 400 bucks so, if the snooty Surefire 'flawless beam' folks can get a bad bounce in the 'luxeon lottery' and end up with a crappy green tint, then I guess it can happen to the other manufactures as well.

They call it the 'luxeon lottery' because early high power Luxeons were all over the map on color, and there wasn't a lot you could do about it except pony up you money and take a chance on what you would get. In my experience about 8 times out of 10 you will end up with a fairly nice white neutral tint, but sometimes - YUCK!

This is still true to an extent, but there are some things you can keep in mind that might help a little.

First, most of the CREE lights I have seen are a bit on the 'cool white' side. While SSC-P4 lights (includeing the LM31, LM33), are a bit warmer, while Rebel lights are slightly warmer still. Also the LM31 and LM33 use a simple resistor dropping scheme for low mode which is not very efficient, so to get a nice long runtime they have to cut the output WAY down and I don't think most folks will find the 'low-low' mode that the lumapower fans like to brag about very comfortable for reading on a long term basis.

Non-pwm lights like the Lumapower have their problems as well. To get lower output without PWM you have to lower the current drive to the emitter, and sometimes the tint of the emitter shifts very noticeably when you do this. A light that starts out 'water white' can shift to 'sickly green' in low mode. I personally don't mind a light that just shifts slightly towards the red/yellow end of the spectrum (like a tungsten light verses a halogen light), but I can't stand 'off tints' in the purple or green range.

Because Luxeon and Lumiled Rebel based lights generally have warmer tints, a good possibility for your reading light would be the Fenix L1T (single AA) or the Fenix L2T (2 x AA) with a Rebel 80 or Rebel 100 emitter. These models use only current regulation for high and low modes, and no PWM is used at all, so tint shifts could be an issue, but if you get one that splits the difference and has nice pleasing tints on both high and low, it would be a real winner.

I mentioned the difference between the way the tints work in high and low modes on PWM and current regulated lights so you can understand the flicker vs. tint shift tradeoff.

Other than this possible slight color shift on low for current regulated non-pwm lights, ANY light can get ANY tint (it's a function of the emitter type and 'luck of the draw' on the emitter color bin and NOT the design of the light).

Personally I prefer a light which uses high frequency PWM, as long as the frequency is high enough not to notice, because it usually insures that the light will remain 'water white' as you drop down to medium and low.

In a higher frequency PWM light, I would recommend something like the Jetbeam C-LE. I have several of them and the tints have all been very white and the low mode is a few lumens higher than the Lumapower lights, which I find gives just enough light for comfortable reading. Early version 1 C-LE's used a lower PWM frequency that some folks could notice, but I have showed my Jetbeam C-LE v1.2 and v2.0 lights to lot's of folks and haven't found one yet that can even see the PWM, much less be bothered by it.

Both the Jetbeam and Fenix lights have super efficient drivers and the runtimes on low are really good (you could read a couple hours a night for weeks before needing to change the batteries).

So with a PWM light, if the PWM frequency isn't high enough for your tastes it may be noticeable, and for a light which uses a 'current regulated' low mode (or a simple resistor like the LM31 and LM33), you roughly double your risk of getting an 'off tint' because even if the light looks good on high it can shift to something nasty on low.

If you find even high frequency PWM is not accetable, and you are super fussy about tint, well, good luck because you may have to go through three or four lights to get one you like.

Hope this helps.
 
Last edited:

Luminescent

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Nice post but LM 31 isn't a cree.

You are correct, my bad. I thought Lumapower switched to CREE's after the Luxeon III's they used to use, but it seems the switch was directly to the SSC P4. I'll edit my post to make a correction.

So far, I have found that on average, the SSC P4's (not to be confused with CREE power bin P4) are not quite as cold as the CREE's and not quite as warm as the Rebels.

I only have a few SSC-P4 lights but I have yet to get a bad one tint wise.

Thanks for the correction.
 

pilou

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Why not just get a proper reading light, any on of the kinds that can be put on a nightstand, the headboard, or even the wall?
 

ernsanada

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BigD64,

Thanks for the feedback.

ernsanada,

Thanks for the comments and the picts. Does look kind of dim-ish for reading. Could just be the difficulty in getting a camera to faithfully render reality, as you note. IIRC, the LM33's "low" is a bit brighter than that of the LM31. Perhaps the LM33 would be the way to go, then?

Jim

I think low is fine on the LM301 for reading in real lfe. The Digital Camera always has a hard time truly representing the actual beam you see.
 

AFAustin

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I am a confirmed read-in-bed-without-disturbing-the-wife guy, and also own an LM33. I had a LM31 when they came out, but have since parted with it.

I love my LM33, and have bragged on it many times in these forums as a great pocket flood light at a modest price. However, IMO, low on the LM33, certainly with an RCR123A but even with a CR123A primary, is too bright. I recall that the LM31 had a much lower low, so it would probably be a better choice. In a dark room, holding a light a foot or two from a printed page, you really just don't need anything very bright.

If I missed this in the thread I apologize, but why are you wanting a 2-stage light for reading in bed? Perhaps you would like the added versatility, and that makes sense. But for strictly reading in bed there are many good 1-stage candidates. I have used an original CMG Infinity Task Light (not the Ultra, which is too bright) for years and highly recommend it, if you can manage to locate one. Also, I recently have used a Peak Matterhorn for the same purpose, and it has a better beam (large, smooth spot) than even my beloved Task Light for bedtime reading.

Good luck with your search.
 
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