Red tinges with video lights

Hi guys,

A question regarding what i think is a new behavior in my video ...

I have a sony FX1 in L&M housing and dual 24W HID video lights.

usually use autofocus and manual white balance as best as I can with white sand etc.

I have noticed on a couple of recent dives that when the lights really light something up, I get a lot of red in the footage. I do not really remember this happening before.

I first noticed this on a dive on the harpoon bomber in lake washington. Vis is routinely crappy in the lake (if you cant touch it you basically cannot see it) -- essentially no way to get a good white balance.

You can see here a universal red tinge. Maybe this could be a bad white balance ?

Then consider this still:

here i white-balanced on some sand, which I know is not ideal.

The purple coral in the far background really is (mostly) that purple, but the blown-out stuff in front just seems really red to me.

I dont remember seeing this redness before -- any thoughts ?

This may sound silly but just check you don't have a clour correction filter screwed to the front of your camera. Second thing I would check is any colour settings on your camera - seems like you have it set somewhere for dark places or wrong exposure?????

are you White balancing without the lights and then turning the lights on after? That would create the red.

The other way to create red like that is to white balance at a deeper depth and then start filming at a shallower depth.

And as Donga said about the red filter. Although you can use filter and lights in conjunction, in the dark water you are diving in i would forget about the filter and just go with the lights as the filter will cut out too much light. The other thing would be if you are white balancing without the filter and then flipping the filter in place, that would also create the red.

Yes, make sure the red fiter is not in place when you WB with the lights on.

Or

Set the WB to the indoor preset and you may be find you are happy with that with your lights on.

What they said.

Also one other thing is that sand is often not the best thing to white balance on. Although it looks fairly white underwater it is usually actually slightly yellow which can give a slight purple tinge to your video.

What they said.

 

Also one other thing is that sand is often not the best thing to white balance on. Although it looks fairly white underwater it is usually actually slightly yellow which can give a slight purple tinge to your video.

Thanks for the suggestions everyone!

I am 99% sure the red filter was not on.

Sometimes I have to either use autoWB or WB on the surface as its just too dark to do at depth (that bomber is the darkest dive site I have ever been on and filled with particles)

Couple of weeks ago, I did a similar thing -- one dive at a dark site, was very red.

second dive (same day) with more ambient light, was fine. I believe both on AutoWB

I have to look into this some more as the red can be hard to get out.

thanks!

MaryLynn said she mwb topside with the red filter down with her A1-U. Haven't seen her results yet

Steve

HID lights are white light (6500) where the red portion of the light spectrum is complete. Since red light falls off first, coral reefs try to soak in as much red as possible. When you hit them with HID lights, the red in the reefs is very strong.

I suggest white balancing with a white card very close to your lens. This leaves very little water between your lens and sensor to difuse the red light. You sensor will then "add" less red into the picture. When you hit objects with lots of red, they won't blow out.

Another option is to hold your slate down in the coral (carefully) and white balance where the red is coming on strong. The camera will then adjust for this and lessen the red.

good luck.

HID lights are white light (6500) where the red portion of the light spectrum is complete. Since red light falls off first, coral reefs try to soak in as much red as possible. When you hit them with HID lights, the red in the reefs is very strong.

 

I suggest white balancing with a white card very close to your lens. This leaves very little water between your lens and sensor to difuse the red light. You sensor will then "add" less red into the picture. When you hit objects with lots of red, they won't blow out.

 

Another option is to hold your slate down in the coral (carefully) and white balance where the red is coming on strong. The camera will then adjust for this and lessen the red.

 

good luck.

Thanks for the suggestions. Manual WB with the Bluefin/FX1 is something of a pain without 3 arms, but this weekend I think my buddy will hold the card for me.

On the bomber dive, I think WB is basically impossible, but the other dives probably I can do it.