really? This is "turbo" mode?

[kbog]

Hello folks. Haven't posted here in years. I had a Jetbeam Jet I on my keychain for a long time. The switch is acting up and I wanted a new toy so I bought a Fenix P1D Q5. This is a very nice light overall, but I was surprised at just how little extra light provided on turbo mode. The first setting is quite bright and turbo is just slightly brighter maybe? My wife says it's brighter...I struggle to see much difference.

Should I be seeing a massive difference on turbo?

Might I have a funky regulator board?

Thanks

 

[Flying Turtle]

Your light is probably fine. There's not really a "massive" difference, just a bit more.

Geoff

 

[txgp17]

The general rule for light perception is that it follows the inverse squares (square root).

In order for a light to appear twice as bright, it must emit 4 times as much light.

To appear 3 times as bright, it must emit 9 times as much light.

 

[kbog]

Alright. So I have a good working unit.

I think part of my perception problem is that the light has to cycle through "off" to get to turbo. If I saw regular mode and then turbo without off between them, the perception of increased light might be greater. Having the light cycle off sort of resets my vision or something.

Not too sure I'm making sense here....:laughing:

 

[optodoofus]

You don't have to go to off between regular and turbo. Just put it on high and then tighten the head. You should jump right to turbo. When you loosen the head, you will go back to low. At least that is how my P1D works.

The other thing to keep in mind is that the turbo experience will depend on the battery voltage. If you have a new CR123 in there, then you should see a noticeable difference. WIth an older battery (or with a AA if you put the head on an L1D body), the difference between high and turbo can indeed be small. Turbo on an L1D is not much brighter than high, but on a P1D/L2D, it is noticeably brighter. Still, it's not a tremendous increase.

optodoofus

 

[scout24]

My fenix p20d is the same way... I expected there to be a big difference between high in one mode and turbo... especially since they claim 90 or so lumen in high and 180 or so in turbo. Yes, it's brighter, but doesn't seem 2x as bright on turbo. That said, I do really like the light.
Scout24

 

[Nake]

You don't have to go to off between regular and turbo. Just put it on high and then tighten the head. You should jump right to turbo. When you loosen the head, you will go back to low. At least that is how my P1D works.

Perhaps you have a P2D and don't know it. :) A P1D is a twisty, tightening the head turns it on.

 

[kbog]

You don't have to go to off between regular and turbo. Just put it on high and then tighten the head. You should jump right to turbo. When you loosen the head, you will go back to low. At least that is how my P1D works.

optodoofus

Mine does not work in that manner. Just tighter is on looser is off.

I'm using new CR123 primaries. I did notice that when I installed a weaker CR123 primary from another light, the settings did not work properly. With the new batt, things function as expected.

 

[divine]

It's really difficult to see how bright the light is by looking at the hot spot. I have to look at the spill, and that makes it a bit easier.

 

[StarHalo]

The one true way of seeing the difference between the Fenix High and Turbo is to go outside at night and light some distant object on High that's near the limit of how far the beam is throwing. Then light the object on Turbo - quite a difference.

 

[Gunner12]

From the numbers, the high mode should seem around 1/3 brighter then medium.(the P1D has no turbo mode, medium-high-low-strobe-SOS) High mode should be 80-90% brighter then medium but our eyes don't sense light linearly. It takes 4x the light for one light with the same beam pattern to seem 2x as bright as another.

As the battery runs down, it will loose the ability to supply enough current to power the higher modes and so the higher modes won't be as bright.

Also try a ceiling bounce, point the light at a ceiling(presuming it's white or close to it) and switch between medium and high and see the difference that way. It might help you see the difference mode but it still won't seem 80% brighter because of how our eyes work.

You don't have to go to off between regular and turbo. Just put it on high and then tighten the head. You should jump right to turbo. When you loosen the head, you will go back to low. At least that is how my P1D works...

I think you are confusing the P2D with the P1D. P2D is clickie with twist head to switch between general and turbo setting. P1D is a twistie.

 

[optodoofus]

Perhaps you have a P2D and don't know it. :) A P1D is a twisty, tightening the head turns it on.

'Doh! I do have a P2D. Sorry about that.

optodoofus

 

[asdalton]

The general rule for light perception is that it follows the inverse squares (square root).

In order for a light to appear twice as bright, it must emit 4 times as much light.

To appear 3 times as bright, it must emit 9 times as much light.

No, you're confusing the inverse square law of distances with the logarithmic perception of brightness.

 

[KIRWILLE]

Hey kbog, I have the p1d q5 and the turbo mode is noticeably brighter, but it doesn't seem to be twice as bright. I think the word "turbo" makes people think you'd better stand back when you turn it on.

 

[asdalton]

For Fenix lights, the main benefit of the turbo mode is the option to get the highest mode on the first click.

 

[grezuki]

I wonder why Fenix set the turbo on the L1D to only 120 lumens versus 94 on high. If you look at the runtimes of 1.5 hours on turbo and 2.2 on high, it would seem possible to trade off some runtime for a higher turbo. For example, if you double the high setting of 94 lumens to 188, shouldn't it then last half as long (1.1 hours)? This probably would be unachievable with alkalines, but why not on lithiums or eneloops?

Anyone know if that wouldn't be possible due to some limitation?

 

[paulr]

Probably limitations on how powerful they can make the step-up converter using components of reasonable size.

 

[ilLUMENati]

The general rule for light perception is that it follows the inverse squares (square root).

In order for a light to appear twice as bright, it must emit 4 times as much light.

To appear 3 times as bright, it must emit 9 times as much light.

Wow thanks, that really settles some concerns that I had about my fenix lights not being that much brighter on turbo mode.

 

[litework]

I was also a little disappointed with the turbo on my P1D, but it's still a lot of light from such a small source, so I'm not too upset. Still, I would rather get rid of the high, so it's one less mode to cycle through to get to the strobe function.

 

[WadeF]

Keep in mind as you increase the output you decrease the efficiency and increase the amount of heat. At the higher levels it takes more and more power to get a little more light and you generate more heat. If they made Turbo mode brighter it may generate too much heat for the small light to handle.

Something like the Dereelight C2H sends 1A to the emitter, and it's a small light, but Dereelight calls this a burst mode. The user needs to know when the light is getting too hot and drop to a lower mode or shut the light off if it's getting over heated. Most of the people buying a C2H are flashaholics that can handle this responsibility. Fenix is marketing their lights more towards the masses and probably doesn't want to sell a light that could burn itself up if the user isn't careful with it.