# Visible difference between ~500 lumens & ~850 lumens?



## tvsinesperanto (Jan 2, 2014)

Hi All,

I'm currently looking for a nice bright EDC light that ticks all the boxes, but no matter what I find, it's always lacking in one or more areas.

I'm pretty much a newbie when it comes to flashlights but I think I've done my homework &, after careful consideration, I've decided that the Olight S10-L2 Baton or the S20-L2 Baton is pretty much ideal for my needs except for the fact that the output is about 50% & 25% lower (respectively) than I would like. Ideally I'd like at least 700 lumens (although more is always better) but the S10 only does 400 & the S20 is only slightly better at 550.

My question is, in the real world, am I going to notice a lot of difference between the 550 lumens of the S20 & let's say the 850 lumens of the Fenix PD35? I'm hoping that the answer is no because the S20-L2 is just about perfect for me with the single exception of it's output.

Of course, I can get EDC lights that will put out 800+ lumens, like the PD35 that I mentioned (850 lumens), or the Zebralight SC600 MkII (>1000 lumens) but these both have other drawbacks (eg. larger size/weight, no tail standing, etc.) or lack nice features that the Olight baton series have.

So, it's a toss up. Do I sacrifice output & get what is otherwise a near ideal light or do I get the output I want but sacrifice other features, some of which are quite important to me? Not knowing how much practical difference there is between 550 & 850 lumens in the real world, I'm somewhat in the dark (pun completely intended).

Is the light level detection of the eye logarithmic like sound detection of the ear (i.e. double the brightness = 10x the lumens), is it a power of 2 thing (i.e 2x as bright = 4x as many lumens), or is it linear (i.e. 2x the lumens appears 2x as bright)?

I would appreciate any experienced opinions on the matter.

Of course if there is some way I can get the same features & durability of the S10/20 AND get 800+ lumens, please tell me. Even if I can only get that output for a few minutes at a time in some sort of turbo or burst mode, that's fine. As I said, I'll only rarely be using it for more than 5 minutes at a time anyway. If it's not possible from a commercial manufacturer, I've heard that some people will make custom lights to suit your needs. If I went down this route would I be able to get a high output in an S20 body? If so, how much am I looking at paying (ballpark figure is fine)?

In case it matters, this light is going to be used for the following:

1) Seeing where I'm going & avoiding obstacles when walking around city/urban streets in the dark. I have minor mobility issues & am a little unsteady on my feet. As a result, if I encounter any unseen & unexpected unevenness in the ground, I'm more than likely to end up on my arse. So, I need to see where my feet are going but I also need to see well ahead (30+ metres) so I can avoid obstacles.
2) Seeing things that have fallen into dark corners or under objects, working on cars or appliances, etc.
3) For inspection of small or fiddly objects when ambient light is poor.
4) Basically just everyday stuff.

Very occasionally it may be used while camping or hiking but it's likely to be only a backup light in those cases.

Any & all advice gratefully accepted.

Thanks,
TV


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## Paul6ppca (Jan 2, 2014)

I think either Olight will be fantastic,When I started out on CPF 40 lumens was great output,and my first jetbeam was 75 lumens on lion battery for 20 minutes!

Remember more lumens always means decreased battery life!


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## thedoc007 (Jan 2, 2014)

If you are talking about shining two lights on a white wall, the difference will be fairly small. As a rule of thumb, generally you need to quadruple the lumens to double the PERCEIVED output (all else being identical). But as TEEJ is fond of pointing out, what really matters is what you can see with the beam. If you take it outside, where you can actually have many reference points, you will notice that a higher lumen light will allow you to see more stuff. And that relationship is very nearly linear, even a small difference in output WILL light up additional targets.

Of course, beam profile is important too. Since 30 meters of throw is fairly undemanding for a modern light, it sounds like you should go for a pretty floody light. This will still allow you to illuminate to that range with no problem, but the wider beam means you will have to move it around less, and can be aware of a wider area around you, as opposed to having tunnel vision from a thrower light.

Check this link for an excellent review from selfbuilt. It seems like the S20 would be appropriate for your use.


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## tvsinesperanto (Jan 2, 2014)

Paul6ppca said:


> I think either Olight will be fantastic,When I started out on CPF 40 lumens was great output,and my first jetbeam was 75 lumens on lion battery for 20 minutes!
> 
> Remember more lumens always means decreased battery life!



Thanks Paul6ppca, that certainly puts things into perspective doesn't it? Maybe I'm just spoilt & am expecting too much.

That said, battery life isn't a major concern for me since I will almost never be using the light for more than a few minutes at a time & I intend to run rechargeables so going through batteries isn't a big problem. I'm happy to sacrifice run time for output.

Thanks for your input.

Cheers,
TV


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## tvsinesperanto (Jan 2, 2014)

thedoc007 said:


> If you are talking about shining two lights on a white wall, the difference will be fairly small. As a rule of thumb, generally you need to quadruple the lumens to double the PERCEIVED output (all else being identical). But as TEEJ is fond of pointing out, what really matters is what you can see with the beam. If you take it outside, where you can actually have many reference points, you will notice that a higher lumen light will allow you to see more stuff. And that relationship is very nearly linear, even a small difference in output WILL light up additional targets.
> 
> Of course, beam profile is important too. Since 30 meters of throw is fairly undemanding for a modern light, it sounds like you should go for a pretty floody light. This will still allow you to illuminate to that range with no problem, but the wider beam means you will have to move it around less, and can be aware of a wider area around you, as opposed to having tunnel vision from a thrower light.
> 
> Check this link for an excellent review from selfbuilt. It seems like the S20 would be appropriate for your use.



Yes, I have already seen that review. It was what got me interested in the S10/20 in the first place.

Hmmm, still a bit unsure about how much difference it'll make. It seems that you're saying that, yes, it will make a significant difference in the real world (since I am far more likely to use it outdoors rather than be shining it at a white wall or similar).

So, just to clarify, you think that the 550 lumens from the S20-L2 would be plenty for my needs? If I remember rightly the S20 has a fairly floody beam spread so it would seem to be suitable from that perspective at least.

Thanks for your input, I appreciate it.

Cheers,
TV


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## thedoc007 (Jan 2, 2014)

tvsinesperanto said:


> So, just to clarify, you think that the 550 lumens from the S20-L2 would be plenty for my needs? If I remember rightly the S20 has a fairly floody beam spread so it would seem to be suitable from that perspective at least.



Yes, I think the S20 will cover your needs very well. 550 lumens is still a lot, and your intended uses aren't overly demanding. Just because there is a real difference doesn't mean that a brighter light is necessary for you.

The rest was just background info, for general education. I always prefer when people give me reasons, rather than just telling me to go a certain way, so I try to return the favor.


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## Swedpat (Jan 2, 2014)

My personal point of view is that I want at least twice the brightness for justifying a new flashlight for the sole reason of getting a brighter light.
The perceived difference between 550 and 850lm is visible but pretty small. If the 850lm light has a more throwy beam profile than the 550lmm light and I appreciate that for my needs it could be justified(if the result would be at least twice the hotspot lux), however.
Apart from that I agree with other opinions here; 550lm is still a lot.

Regarding perception of brightness differences I have found that it usually demands ~ three times the brightness to be perceived as twice. At low lux intensity I have found that the perceived difference can be less, so it's not always easy...


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## Capolini (Jan 2, 2014)

Like most of us I have a sufficient amount of torches!

I have the S10 and the S20. They are very petite[especially the S10] yet bright enough and surprisingly "floody". I use them around the house and to take the Siberian/Wolf out for last call[bathroom break!!] before bed! Again,Both of them flood a large area. The first time I used them I was very impressed in that regard.

If you were choosing one, I would definitely recommend the S20 because of more output and a "low battery indicator"!

Good luck.

p.s. ....Partially off topic!! The fine gentlemen below turned me into a Flashaholic. He will be VERY HAPPY[ME TOO!] with the snow, cold, wind and potential blizzard conditions that will be here in a few hours!!


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## tvsinesperanto (Jan 2, 2014)

thedoc007 said:


> Yes, I think the S20 will cover your needs very well. 550 lumens is still a lot, and your intended uses aren't overly demanding. Just because there is a real difference doesn't mean that a brighter light is necessary for you.
> 
> The rest was just background info, for general education. I always prefer when people give me reasons, rather than just telling me to go a certain way, so I try to return the favor.



Cool. Thanks for that & thanks to everyone for their advice.

OK, so my short list has now been pared down to just 2 lights. The Olight S20-L2 Baton & the Jetbeam RRT-01. Out of these 2 lights, which do you think would serve me best? The Jetbeam has 50 extra lumens, is smaller/lighter & has the nice control ring interface. These appeal to me but I've heard the beam is a bit "ringy" due to the reflector used. I don't know why/if that's a problem though (one of the many subtleties of the flashlight world that I do not yet understand). I also don't know if the RRT-01 is as floody as the S20.

Thanks again,
TV


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## Paul6ppca (Jan 2, 2014)

I have the rrt01. I love the ring and with XML it is. Real big hotspot/floody beam. The newer jet beams have a lop reflector so it should not be ringy at all. Mine is the original smooth reflector and rings are only visible at extreme edge of the beam,while white wall hunting. In real use I don't notice it. It's a great EDC light and nightstand use. It goes lower than just about any light. 
I would recommend it.


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## Ryp (Jan 2, 2014)

tvsinesperanto said:


> OK, so my short list has now been pared down to just 2 lights. The Olight S20-L2 Baton & the Jetbeam RRT-01.



Well the S20 has a strobe while the RRT-01 does not, if that has any effect on your decision.


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## tvsinesperanto (Jan 2, 2014)

Ryp said:


> Well the S20 has a strobe while the RRT-01 does not, if that has any effect on your decision.




Ahh, good call. Yeah, I forgot about that. I don't think that I'm ever likely to need strobe but it is nice to know it's there just in case. I think the RRT-01 also lacks a low battery warning doesn't it?

Anyway, yes, for those, & a few other reasons, I think that I have settled on the S20. It seems to be the best all rounder I've seen & has the most useful set of features for my needs.

I want to thank everyone for their help on this. You must get a lot of newbies asking for similar advice over & over & I appreciate everyone's willingness to patiently explain the basics to me & give me the benefit of their experience.

I really appreciate it. Thanks.

Now all I have to do is find somewhere that will sell me one. Not an easy task in Sydney where you can get any flashlight you like, as long as it's a Maglite or LED Lenser. ;-)

Cheers,
TV


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## thedoc007 (Jan 2, 2014)

tvsinesperanto said:


> Anyway, yes, for those, & a few other reasons, I think that I have settled on the S20. It seems to be the best all rounder I've seen & has the most useful set of features for my needs.



Good choice...the RRT-01 will not take an 18650. To me that would be the single biggest reason to go with the Olight. 18650 offers FAR better runtime than RCR123. Will literally run several times longer - even if runtime isn't critical, not having to constantly charge is better.


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## Brasso (Jan 3, 2014)

Given equal beam profiles, you will barely notice a difference 550 and 850 lumens even when using the two side by side. So don't worry about it.


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## thedoc007 (Jan 3, 2014)

Brasso said:


> Given equal beam profiles, you will barely notice a difference 550 and 850 lumens even when using the two side by side. So don't worry about it.



As I already said, if you are doing a white wall test, or just shining it around inside, they will appear similar. But if you are using it at ranges that actually test the light's capabilities, you will notice a significant difference. It is disinformation to say the difference is barely noticeable. Again, the key is not to compare how bright the lights seem to be (humans are TERRIBLE lightmeters) - the idea is to SEE with them. The higher lumen light WILL light up a lot more stuff. This is hardly surprising, after all. Lumens are empirically measured, and an extra 300 lumens is a LOT more light.


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## Yamabushi (Jan 3, 2014)

At http://fonarik.com/test/indexen.php?model=245&scene=1&mode=1 you can compare the PD35 at 850 lumens and 450 lumens. There is a visible difference.


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## TEEJ (Jan 3, 2014)

Yeah, its a visible difference.

Another thing to remember is that the beam SHAPE will make you perceive the output differently, even if the lumens are the same.

Humans always PERCEIVE the light with the brightest hot spot as "brighter".

If I take a 130 lumen tight beam and a 900 lumen flood light, and shine them on a wall 10' away, every one says the 130 L light is brighter...as there's more LUX in the hotspot.

We see LUX...not lumens.

So if we are comparing two lights with the same sized hot spot, corona and spill, its easier to compare if one is brighter.

If we are comparing two lights with even slightly DIFFERENT proportions of hotspot, corona and spill, its almost impossible to SEE the difference on that wall....as far as which is "brighter".

For example, if both have the same lumens, but, one has a larger (But therefore lower cd) hotspot, once the hotspot lux is "over range" for our eye's "light meter", we SEE the light with a lower cd as brighter at that 10' wall shot. (We perceive it as a "Bigger bright spot")

If we backed up so the wall was 100 meters away, THEN we might see that the larger, but more diluted hotspot, didn't have the range that the smaller, but more concentrated hotspot had. (The increased range in that case reverses our impression, by reducing the lux to within our response sensitivity)


If you compare to floody beams, and one is even a LITTLE wider, the wider one would need lot more lumens to have the lux on stuff in the middle of our field of vision look the same, and so forth.


Now, sometimes, the beam angle is more important than the overall lumens, if the extra lumens are not somewhere useful to YOU. 

This is why, for long range lights for example, that an XPG2 with 600 OTF lumens might work BETTER than a XML2 with 1500 lumens.

Its also why for hiking, etc, you don't need a high cd light, but you might need MASSIVE lumens to see both snakes/roots AND looming tree branches, etc, at the same time...BECAUSE the beam angle needs to be very wide to allow that FOV.


So, discussion of lumens in of themselves can be misleading, but, if you use targets as a reference, as mentioned above, you can observe more ITEMS/FEATURES of what's out there with ANY additional lumens, and, its just a matter of degree as to how important that is to YOU. 


Real world example, if running at night on rough terrain, you speed dictates the lead time you have before you reach something requiring your reaction...the faster you are going, the more distance you cover in a second, etc.

We need some reaction time to see the uissue, recognize that it IS an issue, formulate a reaction, and, then initiate and execute that action. For a guy with quick reflexes, that could all take place in 1/10 to 1/2 of a second.


To resolve what we are looking at, it requires a certain minimum lux level. The finer the detail, the more lux it requires.


To not run into a tree, not much lux is needed. To tell a Timber Rattler from the dead leaves, a lot of lux is needed, as its hard enough in broad daylight. 


Roll all of that together, and, for that scenario, the light must provide enough lux on the stuff out there to allow safe transit.

The faster you are trying to go, the more light you'd need. 

The guy going 1 mph will say "All you need is X"

The guy going 5 mpg will say "X?!?!?! WTF are you THINKING?!?!!?"

And then they argue because they BOTH KNOW THAT THEY ARE RIGHT. (For them. Som people just have a hard time imagining that someone else's experiences could be different, w/o being wrong)


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