How many lumens before the fish swim away?

[LowDrag]

lowdrag, huge difference between spots and spread beams in lights unfortunately, the 1k video head should be fine. I wouldn't turn the spot on unless you have to. The video patterns don't tend to spook creatures in caves that are operating in true pitch black, but if you get the hot spot from a primary near them, they dart off.

Good to know, thanks. Complete newb here when it comes to what lights work for what.

 

[Steve_C]

Depends on the critter.

a. Food does not like lights it can upset their vision and make them more visible

b. Eater often is attracted to lights. See part a.

 

[tbone1004]

Steve, sharks have a particular fondness for HID light heads..... they rub up on them, not as bad with LED's

 

[dumpsterDiver]

If it is sunny you will surprised how LITTLE light the wide angle lights throw in the day. They will light up subjects maybe 4 feet away, further than that, you probably will not see any difference in light.

 

[3D diver]

I use 4 1000 lumen DRIS lights---the original 1000 lumen modified with holographic diffusers for several years, now using the new Impact lights with video heads---and I haven't observed fish being frightened off by them. I've had fish, cormorants, seals and sea lions approach because of the lights.

For bright subjects, nudibranchs mostly, I'll swivel two of the lights away to get a better exposure.

 

[Centrals]

I use 4 1000 lumen DRIS lights---the original 1000 lumen modified with holographic diffusers for several years, now using the new Impact lights with video heads---and I haven't observed fish being frightened off by them. I've had fish, cormorants, seals and sea lions approach because of the lights.

How about night dive?

 

[3D diver]

Harbor seals hunt in my lights:

 

[Centrals]

Harbor seals hunt in my lights:

But you won't see them swimming at night!

 

[3D diver]

I saw them fine...and petted them.

 

[Hintermann]

If it is sunny you will surprised how LITTLE light the wide angle lights throw in the day.

It is not just during the day; you can see the difference between a standard and wide-angle light even at night. I have TWO 1000 lumen lights - one a Buechat that I use for night diving and the other an Epoch wide-angle for close video-clips. On a couple of occasions I forgot to recharge the Buechat's batteries on time and took the Epoch instead and the difference was obvious. The Epoch lit up a greater area close-up but lacked the penetrative ability of the Buechat.

Light obeys the Law of Inverse Squares and that explains why the illumination falls off so dramatically with increasing distance in wider-angle lights.