a very specific question re. which light

[Kharon]

I am having the most extreme trouble getting anyone to answer this question which is very simple and extremely specific. Everyone seems to want to include a camera, video advice, filter advice. I don't want any of that. I only want the answer to exactly the question that follows.

At 60 feet in gin clear water and at distances of 3, 6, and 9 feet from a Spotfin Hogfish (bright red and bright yellow), with which light would I see (with my eyes - no camera) the colors of the fish better at the center of the beam - a 1500 lumen 110° beam light or a 700 lumen 75° beam light.

 

[nimoh]

assuming the light is spread out evenly throughout the beam, then mathematically, the 700 lumen light would put more light on the subject.

 

[Kharon]

nimoh,

Thanks so much. That's the straight answer I needed.

 

[SlvrDragon50]

If you want to calculate it on your own later on, this link worked wonders for me:

Lumens-Lux Calculator

 

[Interceptor121]

Both lights will be useless in the conditions you describe
Maybe you will notice something at 1 max 2 feet

 

[Kharon]

SlvrDragon50,

Thanks for the link. Very interesting that the Lux values at 3, 6, and 9 feet are nearly the same for both lights. The 1500 uses 2 batteries with a burn time of 50 minutes at 100% and the 700 uses 1 battery with 160 minutes at 100%. I'm exchanging the 1500 for the 700. The 700 will make a better night dive light as well.

Interceptor121,

Not sure why you say that. I used a PrincetonTec Shockwave II (200 lumen, tight beam) on a night dive and the color was much improved at distances of at least 12-15 feet, perhaps more. I'm not an absolutely top-of-the-line type guy, I'm just looking to see some improved color in the coral and fish instead of black & white during a dive.

 

[Interceptor121]

On a night dive the conditions are different as it is pitch black
In daylight those lights and actually many other will be irrelevant in clear blue water
After 6 feet your lights will disperse in the water like a little drop