Visual fatigue

maxrep12

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Some years ago tubeless tires were introduced to the sport of mountain biking. The premise was that a tire that did not use a tube could be run at lower air pressures without the risk of pinch flatting from rocks or roots.

The manufacturer developing this wheel system did not find the acceptance they had hoped for. Undaunted, this manufacturer flew quite a few pros out to their facilities for some testing.

First the riders did a warm up lap. Next, they were instructed to inflate their own tubed wheelset to whatever psi(air pressure) they desired. Then they were told to let it rip out on the course as they would be timed. After these pros finished the first timed lap, their wheelsets were swapped out for tubeless ones. The manufacturer at this point inflated the tubeless tires to a much lower psi. The cyclists were sent out a for a second timed lap.

As the riders pulled off the course after this second timed lap, every last one of them swore the second lap on the tubeless tires was not as fast as the first lap on their own higher psi tubed wheels. And they were all wrong. The timing clocks told no lies.

The reason these seasoned racers perceived their first timed lap to be the fastest was due to the higher air pressure. Every rock and root hit sent a more solid impact into the racers body. They endured more physical jarring, and they were more fatigued at the courses finish. They attributed a higher average speed to causing all this body pounding. In the end, it was concluded that having a lower psi tire conform to the shape of rocks and roots, was more efficient than having higher psi tires bounce vertically off of them.

I would submit that with lighting, tight and bright hot spots produce a similar situational misreading. Left to our own devices, it is likely we view the contrast of a narrow bright beam with relation to dark surroundings as being more effective, or superior. In truth, when compared to flood beams, the thrower has shown us less, but we give it credit for more. This is the illusion of visual fatigue.

At any 24hour bike race, it is all flood lights. No throwers thrashing about in the night sky like light sabers. In timed events, these cyclist have found that you are most capable when using your eyeballs as intended. That means having access to your peripheral vision. In the woods, a thrower will cause you to overshoot every turn, resulting in excessive braking. This is the reality of how our vision functions. What we visually track in our periphery provides far more information than what we detect at our focal points.

Yes I know, we were all nocturnal snipers in another life, and needed throwers then. But this is not that life.:laughing:
 

Richsvt

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I like your comparison. I do think that as evolution has progressed in eyesight, our peripheral vision has been somewhat neglected. Instinctually, we still access it but we do not give enough attention. I need to go out in the woods with both types of lights to test this out...
 

shq_luvlights

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Yes I know, we were all nocturnal snipers in another life, and needed throwers then. But this is not that life.:laughing:

Lol I love this statement. Ever since I found out I am a flashaholic I love to test my lights and I find myself loving the thrower of the bunch. I guess it is fascinating that we are able to see so far when it's dark outside. But in ur case I guess its true somehow. Both are important.
 

whiteoakjoe

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I agree with your assessment 100% I also find that a neutral tint or warm tint is precieved as a much dimmer light, however (for me) I find that I see better with them, and pick out details much quicker. A tight blue beam looks bright but for most of what I do an XML in neutral with a OP reflector and wide spill, is so much better. If I'm out at night I like to use a light that does not cause my pupils to drop down into bright sunlight mode, I want to see and still maintain some night vision. (and at 40 that is not as easy as it was at 20 trust me young pups it will happen to you also)
 

maxrep12

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Hmmm, that was cryptic.

Try this. In the room where your computer is located, turn off all the lights and close any doors to adjacent rooms. Now sit down in front of the computer in total darkness and browse the internet for awhile. Ahh, now we are experiencing visual fatigue. Your surroundings are dark, and you are looking at a hotspot beam that is brighter than it should be.
 

maxrep12

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I agree with your assessment 100% I also find that a neutral tint or warm tint is precieved as a much dimmer light, however (for me) I find that I see better with them, and pick out details much quicker. A tight blue beam looks bright but for most of what I do an XML in neutral with a OP reflector and wide spill, is so much better. If I'm out at night I like to use a light that does not cause my pupils to drop down into bright sunlight mode, I want to see and still maintain some night vision. (and at 40 that is not as easy as it was at 20 trust me young pups it will happen to you also)

I am interested in CRI improvements in lighting. At times I wonder why light manufacturers don't offer lenses with subtle tint coatings to boost some deficiencies in the emitters color spectrum.
 

maxrep12

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I like your comparison. I do think that as evolution has progressed in eyesight, our peripheral vision has been somewhat neglected. Instinctually, we still access it but we do not give enough attention. I need to go out in the woods with both types of lights to test this out...
IMO, the best test is to have an individual that has zero knowledge of lighting head out into the woods for a few consecutive evenings. First night they get the flood, second night the thrower comes out. The third night they will choose the flood light on their own accord. Removing bias is half the challenge.

If you use a light in tandem with another activity, utility will win out. Hiking with a thrower provides a narrow field of view with a tedious hotspot. I imagine at the Grand Canyon, a thrower would be the right tool to enjoy the view.

I take my wife to the beach regularly, for the sole purpose of exercising my peripheral vision. "No, uh uh, I didn't see that lady. As you can cleary tell, I'm all focused on the horizon".
 
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Jash

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As someone who has spent hours upon hours in the saddle of a MTB (came 11th overall in the state championship a few years back), I find the analogy lacking. Depending on the course, you could have wanted anywhere between 22-60psi. When you are racing on hard packed dirt, it's almost like riding a sealed road and high psi will get you there faster. On loose gravel and tracks littered with ruts and tree roots, lower psi is the way to go.

When I hear the dog barking at night, I don't grab a flood light. I grab a thrower and set it to max. If I'm walking the dog at night, then I'll tend to favour a floodier light. It's horses for courses, and to say that throwers are redundant is not understanding the various needs we have for night time illumination.
 

bansuri

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Yep!
Once you break out the big throwers in the wrong environment you can't see anything without them.
However, this is not an argument you can win with logic or good examples; some folks like it as bright as possible and we have to allow that we are all entitled to our own opinions.
I need a super-bright light during the day to overcome the contrast between overhead fluorescent lights + daylight coming in from skylights and the shadowy interior of machines.
At night I like to use the least amount of light possible to conserve battery life, not draw attention to myself unless needed, keep my eyes adapted, and as a consideration to others who might be with me. (finally broke my kids of the habit of shining the light on my face when we're talking while out with flashlights. The adults are harder to train.)
And I have to admit, there is a HOLY MOLY! factor to consider, the lights we can get today are nothing short of amazing in regards to output and it's pretty cool to throw out that level of light from a small light.
Glad we've got a place like CPF to learn about these lights and communicate with like-minded people.
OOh, also, it thrills me to think that the little red LED's that were in my Texas Instruments digital watch back in '78 that you could kind of use as a flashlight in a totally dark bathroom have evolved into what they are today.

My first LED "light":
2ihqkqh.jpg
 

reppans

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While I certainly do agree with floody lights being more useful, just on the basis that the majority of most people's illumination needs tend to be within fairly close range, I would have thought this was fairly obvious to most flashaholics - unlike your tubeless tire analogy. If you look at any "floody vs throwy" poll, floody seems to always win by a decent margin.

Having said that, I really do like your tubeless tire analogy and think it would fit much better if you were talking about using dim modes, as in, which could you see more with - a bright light or a dim light? In this case, I'm not talking about a bright 10 degree hotspot drowning out the other 70 degrees of peripheral spill, rather, I'm talking about a bright 80 degree beam drowning out the other ~200 degrees of your naturally illuminated peripheral vision. If you look at the average output-used polls (there's one running right now), it seems most people are quite heavily weighted on the high lumen side.

As a camper, I personally use 0.3/3/30 lms as my typical LMH trying to match ambient as closely as possible with night adapted eyes. The further I move above ambient just serves to increase the inky blackness outside my cone of light reducing what I can see - I find that scary (and frankly, a waste of batteries).
 
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maxrep12

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As someone who has spent hours upon hours in the saddle of a MTB (came 11th overall in the state championship a few years back), I find the analogy lacking. Depending on the course, you could have wanted anywhere between 22-60psi. When you are racing on hard packed dirt, it's almost like riding a sealed road and high psi will get you there faster. On loose gravel and tracks littered with ruts and tree roots, lower psi is the way to go.

When I hear the dog barking at night, I don't grab a flood light. I grab a thrower and set it to max. If I'm walking the dog at night, then I'll tend to favour a floodier light. It's horses for courses, and to say that throwers are redundant is not understanding the various needs we have for night time illumination.
29er.jpg

You've heard the saying that there is always someone faster than you...Tonight its gonna be yours truly.:devil: Congrats on your placing. What state and class? Yeah, I'll remove my photo soon.
 
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maxrep12

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As someone who has spent hours upon hours in the saddle of a MTB (came 11th overall in the state championship a few years back), I find the analogy lacking. Depending on the course, you could have wanted anywhere between 22-60psi. When you are racing on hard packed dirt, it's almost like riding a sealed road and high psi will get you there faster. On loose gravel and tracks littered with ruts and tree roots, lower psi is the way to go.

When I hear the dog barking at night, I don't grab a flood light. I grab a thrower and set it to max. If I'm walking the dog at night, then I'll tend to favour a floodier light. It's horses for courses, and to say that throwers are redundant is not understanding the various needs we have for night time illumination.
Perhaps you need to read the analogy again. Did you miss the very clear portion about the Pro class riders getting a warm up lap, and then selecting what they considered the optimum psi before they road the first timed lap?

I was one of the first Pros on the Stans tubeless sytem. Your psi ranges are pretty far off. Nobody gets near 60 psi.

Night illumination is something I am intimately familiar with. As a product tester, I have owned every major piece of bike lighting equipment, and have performed testing for Lupine. The number of cpf members that have logged as many outdoor hours with lighting equipment as myself, could be pretty slim.
 
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FoxyRick

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There is a place for both of course, but I fully agree in general and learned this very early on, before LED days, with the zoom head on a maglite. I still love a thrower that feels like a light sabre on a misty night.

Funny thing: Just before first reading this, I was heading into our out-buildings at night and for fun I took a couple of flashlights instead of turning on the overheads. First off I tried out my EA4W. Brilliantly bright, dazzling spot, pupils immediately contracted and I could hardly see anything in comparison to what I turned on next... A Malkoff M60W. Less than half the lumens but it just lit the whole room up perfectly and I could see everything in front of me.

On my night hikes, half the time I don't use any light at all. What's the point of night hiking if I try to make it look like daylight???

If the night is almost black then it's low lumen flood aimed a couple of metres in front of me, just so that I don't fall into a(nother) ditch. I often use my original Zebralite H30 clipped to my rucksack belt for that purpose, so I'm hands-free. A few lumens works wonders for spotting ditches without messing up night vision too much.

If I feel the need for more light, then it's either the Malkoff M60W for flood or (now) my EA4W for long range. And I do use both about equally, looking at a frog at my feet, or spotting a fox at a hundred metres.

I find colour more important than lumens, at least close up, so the old H30 will be replaced soon by something neutral or higher CRI.
 

subwoofer

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I've enjoyed reading this thread as I like the OP's analogy and how our perceptions are not always right.

Having tested all sorts of lights with all sorts of beam profiles, for me flood is King (long live the flood!). Yes, throw is fun and for some applications is needed, but for at least 90% of the average user's lighting needs, flood is going to be far superior and far less fatiguing on the eyes.

I have a 65W HID which has measured at a true 3560lm. Using this in a completely dark environment (no moon) you get absolute tunnel vision and are completely blind to anything beyond the edge of the spill. It is a strange and disorienting thing to use and is very fatiguing. Similarly, some of the bike lights I've used with a tight hotspot make cycling very difficult, and these only really work when helmet mounted rather than handlebar mounted.

Long live the Flood!
 

maxrep12

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I've enjoyed reading this thread as I like the OP's analogy and how our perceptions are not always right.

Having tested all sorts of lights with all sorts of beam profiles, for me flood is King (long live the flood!). Yes, throw is fun and for some applications is needed, but for at least 90% of the average user's lighting needs, flood is going to be far superior and far less fatiguing on the eyes.

I have a 65W HID which has measured at a true 3560lm. Using this in a completely dark environment (no moon) you get absolute tunnel vision and are completely blind to anything beyond the edge of the spill. It is a strange and disorienting thing to use and is very fatiguing. Similarly, some of the bike lights I've used with a tight hotspot make cycling very difficult, and these only really work when helmet mounted rather than handlebar mounted.

Long live the Flood!
Thanks.

The same issue surfaced yeas ago with bike lighting when HID lamps were introduced. Internet forums saw the frequent question, "How much light is too much"? Of course the Welch Allen bulbs back then were only putting out around 400 lumens. In todays environment, cyclists can afford both bar and helmet mount combos which can produce above 3000 lumens. With time and experience, cyclists have come to realize that even 400 lumens from the HID bulbs was rather humble. The growth in output gave us back visual awareness of our environment by enlarging our field of vision, not by increasing throw.

Beam utility changes moved more quickly in cycling both because of the group nature of the activity, which actively showcased real world comparisons, as well as the competitive side of night lighting. When testing lighting equipment among pros, the individual using the wrong tools would quickly get dropped in the single track. Those who dropped off the pace immediately were aware of the cause. The following week these same individuals returned with the proper gear. Getting dropped once in the woods once was all that was necessary for that "Come to Jesus" realization.
 
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Zeyeman

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I am interested in CRI improvements in lighting. At times I wonder why light manufacturers don't offer lenses with subtle tint coatings to boost some deficiencies in the emitters color spectrum.

This is a little off-topic, but there was a post here recently about doing this yourself with photo gels. I got a couple of Rosco filter swatches at B&H Photo, and have tweaked everything from a 2007 Fenix L1D, to a couple of 2012 Preons. Even my Zebralight H30 (which I used to think had a nice white beam :thumbsdow) is sporting a nice corrective filter on the front (which I glued with Gorilla Glue). Before cutting, I search around for the perfect cylinder to trace a circle on the swatch with, then trim with a small pair of scissors. In most cases, the bezel simply holds it in place; on a Quark Tactical, I used a drop of baby oil (a very tiny drop!) to hold the filter in place because I trimmed it too small, and it's still holding fine--I call that the "contact lens" method, and no, there is no diffusion from the oil.

Of course, filters can't make those harsh CW LEDs into magical High CRI LEDs, but you can at least make a CW into a Neutral.
 

RCantor

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The only time I feel eye fatigue is from 6500K lights. As was said above, horses for courses. If you're hiking it's different than if you're looking *for* something. If you're in the forest looking for things under leaves in daylight, you need a bright thrower. Shine the light 50 feet away at the dark spot under the vegetation or in the hollow of a tree and you know if your quarry is there or not. Floods don't work for that. Speeds up work tremendously not having to walk up to every nook & cranny. Doing the same thing at night requires a flood held at different angles. Having a thrower along can help, but 95% of the time all I use is the flood at night.

Filters don't boost deficiencies, they drop everything else, as I'm sure you know. That's fine if you have the extra lumens. :)
 
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