Question regarding regulated and total light

[rydude07]

Hey guys. I actually have 3 questions:

1) I am looking at the princeton tec Genesis because it is on sale for $40. That a good price?

2)It says that burn time 1.75 hours regulated , total burn time 20 hours.

What does that mean?

Someone says that it means that the light can be on for 1.75 hours and then it will turn off. But If i wait and turn it on again, i can use it for 1.75s etc and turn it off until i get to 20 hours, and thats when it is too dim and need to replace batteries...is that right?

Seems too good to be true?

3) It says waterproof at 1 meter for 30 mins. Does that mean with the light on or off? Can I operate underwater in less than 1 meter of water for 30 mins?


Thanks for helping a newbie out!:twothumbs

 

[HKJ]

Hey guys. I actually have 3 questions:

1) I am looking at the princeton tec Genesis because it is on sale for $40. That a good price?

2)It says that burn time 1.75 hours regulated , total burn time 20 hours.

What does that mean?

Someone says that it means that the light can be on for 1.75 hours and then it will turn off. But If i wait and turn it on again, i can use it for 1.75s etc and turn it off until i get to 20 hours, and thats when it is too dim and need to replace batteries...is that right?

Seems too good to be true?

3) It says waterproof at 1 meter for 30 mins. Does that mean with the light on or off? Can I operate underwater in less than 1 meter of water for 30 mins?


Thanks for helping a newbie out!:twothumbs

The regulated time is how long before the brightness start to drop, the total time is how long you still have some light. If you turn it off and wait some time it will probably start at full brightness again (because batteries recovers some when off), but it will soon start to drop in brightness again.

You can not trust these waterproof specifications, they usual mean that the light will survive being dropped in a puddle, but not much more. If you have lubed the o-rings and are a bit lucky, the light might survive longer time in water.

 

[carrot]

It will run for that long at full output and then gradually get dimmer over the next few hours. How gradual depends on the circuit. It will not go back to full brightness if you switch it off at this point. If I recall correctly the Genesis uses lithiums which don't have a very pronounced recovery effect as mentioned.

Princeton Tec being a well known maker of underwater lights, I would trust their ratings. It should work fine on or off in your stated conditions.

 

[divine]

Here is a review of the Princeton Tec Genesis.

http://www.flashlightreviews.com/reviews/pt_genesis.htm

About half way down it shows a runtime graph of how much output the light has versus how long the light has been running. It will give you an idea of how it works. Also, check out that the real world testing of this light is different than the manufacturer's results. (The testing in the review does not show out to where the manufacturer says the light stops putting out light.)

 

[divine]

That is a pretty old light, the review was done in 2006. I think you should look for something a little more updated. (Unless I'm linking to you to the wrong review. )

 

[rydude07]

Yah it is an old light. But, it is on sale for $35 plus shipping and that is why I am looking at it. I have heard some good reviews on it and it seems like an awesome deal...is it?

I want a long runtime but bright as well. So about after 3 hours, it woud start to get dim, but how usable is the light after about 3 hours of use? Would it still be usable until the 20 hr max limit? (of course not continuous use but on and off)

Is this runtime pretty good for a flashlight that gives this amount of lumens?

 

[Ragiska]

no, it's not really a good deal. no, the brightness/runtime is not good. the light is two generations outdated. a modern equivalant light can offer over four times the brightness for the same runtime, or four times the runtime for the same brightness, or a combination of the two (which is common since many lights have multiple modes now).

 

[csa]

Yes, that's a bad deal, don't buy the light. Buy a modern light with modern technology. You can get much better options today.

I don't understand your fixation with turning the light on and off over the course of 20 hours - the runtimes are based on total light-hours used. If you turn it on for 5 minutes, then turn it off, you have 5 minutes less usable total light output.

Don't expect a light like that to have a usable level of brightness after a couple hours. You might be able to read a book in the complete dark, but don't count on much more.

If you post a question stating what specifications you're actually looking for in a light, people here can recommend good options for you.

 

[gcbryan]

You also don't mention if you are intending to use it as a dive light. Princeton Tec makes dive lights but they also make other lights. This is not a dive light.

The 1 meter for 30 minute test is a European Union standard for water resistant as in can be dropped in a water puddle.

It may be able to go deeper but it it's certified to do so and most likely would soon flood.

The post above has it right. For the money it's not a good deal.

 

[rydude07]

Thanks a bunch for your help guys. I won't buy it. I will post a new thread about what I am looking for .

You can close this thread. thanks !!