Halogen or LED for clear waters??

[whitenoise]

Hi everyone,

You all seem really, really knowledgeable (way over my head!) about such things so I thought I would ask you for advice! I'm looking for a new dive torch but I can't seem to find just what I am looking for. I've been looking for a handheld torch that I use down to 35m for use in both clear waters (ie red sea etc), but also for use in the UK.

Initally I had posted on a diver forum asking what was the best recommendations for adding some colour back to reefs/fish was, however I was informed that I would need a twin 250 HID setup to even come close. Now I don't know if this was lighting a whole wall or something (or maybe this IS whats required?!), but I was just after a nice torch which I could use to light up just small parts of whatever I was looking at. Wouldn't want to annoy other divers with massive floods, (which wouldn't have enough power anyway), but on the other hand didn't want a 'techie' style cutting really narrow beam that has some stupid tiny hotspot and nothing else.

So the question I have is Halogen or LED? There seems to be massive difference of opinion on which one is better for clear water, where quite a lot of people agree LED is better for night/murky/green water conditions. I've read that in clear water if the light source isn't going to dominate the ambient light then about 1000 lumens is needed at about 1m distance at a colour temp of 3000-4000k is needed (to counteract the blue ambient light), but others say that more daylight 5500k is needed? I've also read that at least 3000 lumens would be needed?

I'm definately not a electronics expert so whatever I go for is going to have to be off-the-shelf. I've looked at offerings from TillyTec (maxi-light), mb-sub (photon2), greenforce (fII pro dimmable), hartenberger (mini compact lcd) and frankly my head is going round in a spin!

Can you people point me in the direction I should be looking?

Cheers!

 

[Packhorse]

Opinions are like a$$holes. everyone has one and they all stink!

And it sounds like you have been given some real stinkers!


Forget halogen. Its last century's technology and has no place in a modern dive light.

Its either HID or LED.
Unless you are a photographer then forget about colour temp. Your eyes will adjust and you are not going to miss anything. Sure LEDs and HID tend to be quite high in colour temp but you will still see reds and oranges etc.
for example this pic was taken with only LEDs for light. Do you think it lacks colour?

Beam angle really comes down to personal choice but a flood type beam is going to be absolute crap in bad viz conditions. Give me one of those techie style beams with the stupid tiny hotspot any day!!

 

[gav6280]

IMHO, LED all the way! and i would think 1000 lumen would be quite sufficient for us green water chaps. My personal preference is around a 10 deg or narrower beam for normal UK diving. Then add a diffuser on top if your videoing or night diving.

P.S i am actually attempting a group buy on YD of a P7 light if interested, Im not allowed to post a link here but go search for it if you like.

 

[Hallmcc]

Initially I had posted on a diver forum asking what was the best recommendations for adding some colour back to reefs/fish was, however I was informed that I would need a twin 250 HID setup to even come close.

Man have you been fed some poor information. Welcome to the board by the way!

First thing to remember is you are not adding color, it is all ready there. All you need to do is bring the spectrum of light each color reflects within the area you are viewing.
In clear water while you may have up to 60 meters of visibility the reality is you are only viewing 3 or 4 meters at a time. Your area of focus is generally less than a meter.
Twin 250 watt HID would white out a meter wide area from 3 meters in. It would only work well for video of a large group from larger distances.

So the question I have is Halogen or LED? There seems to be massive difference of opinion on which one is better for clear water, where quite a lot of people agree LED is better for night/murky/green water conditions.

Turbidity requires a tight focus to slice through the particles, flood lights reflects back and reduces your ability to see. It really is not the type of lamp as much as the focus. Clear waters are more forgiving and the more you can see the happier divers are. Halogen Mr16 based dive lights were inexpensive (comparatively) ways to flood large areas with light. LED based lights can be created to fill the same area and as the technology catches up I think you will see those types of lights appearing more for you fortunate ones that don't have to fight with one meter visibility.
Halogen lights commonly used are real battery hogs and have short runtimes, LEDs have a much lower power requirement and therefore have teased divers with promises of more for less.

I've read that in clear water if the light source isn't going to dominate the ambient light then about 1000 lumens is needed at about 1m distance at a colour temp of 3000-4000k is needed (to counteract the blue ambient light), but others say that more daylight 5500k is needed? I've also read that at least 3000 lumens would be needed?

I am sure you have used some type of hand held light on a dive before. Before falling for what some "expert" put in print ask yourself if that rings true in your experience. That is simply not accurate for the diving you have asked about. I have photographed color return with a few as 170 lumens from a light. It is about distance and how close you want to get. Look at Packhorse's' photo, he has tons of them using all different types of lighting all quite clear and colorful. I bet he has yet to put 3000 lumens anywhere near the water.

Can you people point me in the direction I should be looking?

Cheers!

Sure, you just found the best place to start.... Right here! :wave:

 

[Packhorse]

.................. I bet he has yet to put 3000 lumens anywhere near the water.

The light ring that I used for that shot uses 24 Luxeon K2's direct driven so it would be close to 3000 lumen. And of course the small flash on my camera probably puts out even more ( but for a extremely short period).
But both would be crap as a dive light.
IMHO 3000 lumen is over kill for a dive light ( not for photography) and I dont see much point in using over 2000 lumen. My light is 1000 odd lumen and I find it puts out more than enough light.

 

[Hallmcc]

I stand corrected.

 

[whitenoise]

Wow, that's people that's very interesting information, thanks to everyone for pointing me in the right direction once again =) THanks for the welcome as well!

I was only looking at halogen since they had the much lower colour temp which I thought was important, but you have taught me the error of my ways! Yes I see what you me about the picture, can I ask what torch was used in the pic, lumens, angle etc? As Hallmcc mentioned do you have other pictures which I could look at to see the differences in LED power?

Looking around there seems to be a "new generation" of focusable LED's which look good. For example Kowalski have LED's with a 9 degree to 35 degree angle. They are using a CREE MC-E 10 watt and the battery life isn't that good so ruled them out quite early on. I also notice that mb-sub are releasing a new focusable LED "soon" which apparently is focusable from 2 degrees to 35 degrees. Apparently providing 17,000 lux nearer the 35 degree range, and 21,000 lux near the 2 degree range, powered by a 3 x aaa and 3 x c-cells?! This looks promising?

Thanks Gav for your advice as well, I shall bear in mind the advice about 1000 lumens probably being sufficient. I shall look at the torch you mentioned.

THanks also Hallmcc for your tips, glad you have cleared up the matter with the twin HIDs. Good tips on the different angles of the LEDs. I think thats why the focusable LEDs look promising. When in bad vis you can narrow the focus to cut through the water, or if in clearer conditions (or closer to the object in murky conditions) you can simply expand the focus to see more. All this can be done in one torch without the use of additional lenses, diffusers etc. Wouldn't these cut down/filter out some of the light output anyway?

 

[Packhorse]

http://www.candlepowerforums.com/vb/showthread.php?t=227965

This was the light I used.

Im not expecting anything great from these focusable LED lights. The ones I have seen so far are very disappointing. As for MBsub doing a 2 degree beam... well lets just say Im not holding my breath on that one.

The real question is how much of the light is focused into the quoted beam angle. Usually it quite a low % resulting in a beam that still has a lot of flood.

It would be helpfully if dive light manufactures showed a picture of the lights beam against a white wall yet very few do.

 

[whitenoise]

That light does look funky, although not sure its something I could take on holiday

Which of the focusable LED lights have you seen already? I agree that sometimes trying to compare torches is really difficult what with lumens and lux, different light angles etc etc.

Well at least you've convinced me that LED is the way to go, now just to keep looking to see which LED torch! Going down the off-the-shelf version is not cheap!