confusion with light ratings

[steve6690]

I have had a Princeton Tec Surge for about a year. Never used it on a night dive but it made a good fist of illuminating the interior of the Stanegarth and the Thistlegorm by day. I bought it as a primary until I can afford a "light sabre" in which case it will become my backup. It takes AA batteries which you can get anywhere and you get ages out of a set of Duracells. I think it's a great torch for the money.

[Woz]

I'd have an Expedition Star out of that lot. Here's a photo of a 5.5W SL4 (left) next to an Expedition Star (middle) with a 14W 8 D cell lantern on the right:



The big difference in burn time- you get 25 hours from an Expedition Star and about 2 from an SL4 if you are lucky.

[n_wood60]

thanks for all the replies so far.
I am tempted with the tektite...especially after seeing it in action in woz's picture. still somewhat undecided though especially with all the replies recommending the 7.5watt (and the negatives abou it).

I'm going to do some thinking and try and get hold of one to try I think before I shell out the cash.
Thanks again everyone

[Darren555]

I also use an Expedition Star & have been very impressed with it both as a backup and holiday torch.
My only issue with it is that the rubber guard keeps falling off which eventually meant I lost it but I have replaced it with a snug fitting piece of innertube but Wally has promised to get me another one.

[Woz]

Originally Posted by Darren555

I also use an Expedition Star & have been very impressed with it both as a backup and holiday torch.
My only issue with it is that the rubber guard keeps falling off which eventually meant I lost it but I have replaced it with a snug fitting piece of innertube but Wally has promised to get me another one.

Either superglue it on or chuck it away and use some black tape on it.

[broady]

...or before you lose it some fabric tape underneath (like in hose repair kits)

Got to agree with choosing the Tektite Expedition Stars though. I took advice from searches on here for a backup torch for Nic and I and we both think they're great. Rob Lumb ( Lumb Bros Greenforce Distributors in the UK ) sorted them out for us super quick - great people to deal with. Sensible money for a back-up too I felt.

Cheers

Graham

.

[Rookie]

Just to really screw your head up..................from Wikipedia....

The lumen (symbol: lm) is the SI unit of luminous flux, a measure of the perceived power of light. Luminous flux differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light.

The candela (symbol: cd) is the SI base unit of luminous intensity (that is, power emitted by a light source in a particular direction, with wavelengths weighted by the luminosity function, a standardized model of the sensitivity of the human eye).

In other, more understandable words, Lumens is roughly "light per unit area of focused spot" and candella is total amount of light given out, regardless of focus. Lumens and beam angle are what you need to compare, even then its dodgy, because of different light temperatures (how yellow/white/blue it is).

Personally, I made an insert for my UKD4R, which has 25 x 1000 mcd LED's in, which focus to a 2' diameter spot at about 6' distance. Its nearly as bright as the 18w Xenon bulb (which is still in there also), but lasts about 25 times longer. It took about 4 hours to make, and cost under £10.

Phil