Seeking Tips for Shooting Video of Hawaii Manta Night Dive

[ReadyDiverOne]

Hi all,

Am looking for guidance re shooting video of the famous Big Island Manta Ray night dive, which I will be doing in July. I have the GoPro Hero Black 6, with the shallow and deep filters sold by Backscatter. I also have a Kraken 5000 lumen vid light, which as you may know is ridiculously powerful.

My question is, should I use the shallow filter or not (I assume we won't be deep enough for the deep/dive filter). As you may know, Backscatter make a convincing case that, for day time shooting, one should use the dive filter AND a light for best results. Obviously, it's going to be dark for the manta dive, so I am thinking NO filter, right??

Many thanks.

 

[Barmaglot]

At the risk of sounding condescending, I'll go over the basics here.

Water absorbs different wavelengths of light at different rates - longer wavelengths (red, orange, yellow) get absorbed faster than shorter ones (green and blue). This means that as sunlight filters through the water column, red light weakens much faster than green and blue, resulting in things going blue-ish. Blue light gets absorbed as well, it's just that red light gets absorbed faster - at thirty meters, there's usually still enough light to see, but it's almost all blue and green, as the red light has been absorbed by 40+ meters of water (assuming the sun isn't directly overhead).

Our eyes are pretty good at compensating for this color shift, by GoPro sensors aren't. This is what the filters do - they weaken the green and blue light, to have it (roughly) match the water's absorption of red, so that even though the overall level of light is reduced, the color balance is restored. Since the difference between red and green/blue increases with the thickness of water layer that is absorbing the light, you need stronger filters as your depth increases.

However, if you're lighting things with your own light, and sun is not in the picture, then you stop worrying about depth - you only need to account for the distance between your light and the subject and the subject and your camera - this is how much the light needs to travel to reach your lens, and therefore, the thickness of water layer that will be absorbing your light. Since even a 5000lm wide-angle light doesn't reach out more than a couple meters at night (a wide beam dissipates quickly, and reflected light intensity decreases with the fourth power of distance) your light won't be traveling through more than 3-4 meters of water, obviating the need for filters to balance the reds. In fact, if you do put on a filter, it will likely result in significant degradation of image quality, as your light, powerful as it is, is still far weaker than sunlight, and GoPros aren't particularly great low-light performers.

 

[Oz Chris]

All my photos and videos from the manta dive in Hawaii were shot on a Hero 5, no filter, no camera lights.

The depth doesn’t really matter. All the light illuminating your subject is coming from lights held by divers and sitting on the bottom.

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• Oz Chris
• Jun 12, 2018

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• Oz Chris
• Jun 12, 2018

 

[ReadyDiverOne]

Outstanding, as I thought. I've also read that, for stills, strobes are just a no-go as there is too much backscatter/plankton. Were you snorkeling or diving? If diving, did you have or even need your own video light? Thanks.

 

[diversteve]

The biggest, brightest light brings in the most Mantas. Yours qualifies...lol

My buddy has a 4K lumen video light and he attracted more than the paid videographer on the dive - technically more Plankton...

I may be wrong but I think strobes are Not Allowed anyway.

 

[chess_is_me]

I have done this dive 6 times and will be doing it for a 7th time in July! I dive a gopro and a nikonos film camera. Generally for video you will have enough light from everyone else's lights. You can run your own as well but make sure you have some good diffusers so that you don't just create a hot spot when the manta gets close. Also you won't need any filters, the underwater lights shouldn't need any color correction. The #1 when doing the manta dive is to remember the mantas get close....... very close so don't go down with a big camera rig that can get caught on a manta or injure it. Also don't pop up to get the photo, you will run into them. Finally have a blast and watch out for Frank!

 

[ReadyDiverOne]

DiverSteve and chess, thanks much! Chess, I don’t have a diffuser for the Kraken and you make a great point re the hot spot. I will experiment and use only flood and turn down power. If I had a buddy I would give him or her the kraken to aim at an angle. Thanks for the tips!!

 

[ReadyDiverOne]

I’m going with Kona Honu July 18, anyone else?? Diversteve, I’m going to ask them about the strobes but I’m prettty sure I’m going to ditch them regardless. Don’t want them in the way as chess said.

 

[chess_is_me]

Enjoy the dive! I am doing the Manta and a 3 tanker with Kona Dive Company on July 17th and 19th, then shore dives in between. Last time I called they had been getting 14 Mantas a night so hopefully they stick around!

Also if you go down to your hardware store and find some opaque plastic you can make your own diffuser and secure it with surgical tubing. I have done that in the past.

 

[ReadyDiverOne]

I'm also curious about recommendations re shooting stills. I have the Sony RX100, mark 1, in a Recsea housing (yes, I know, it's old, but it's still enormously capable and effective). This guy wrote a great post about shooting the manta dive:
Swimming with Manta Rays: Tips & Photo Guide - Firefall Photography

In short, he recommends shooting in shutter priority, around 1/250, ISO at 800, obviously RAW. He does say he thinks he could have gotten shutter speed down to 1/100. My plan is to shoot full manual, probably start at 1/150, between F6-F8, and ISO around 600-800, assuming that that exposes at least close to correct; I have the Inon 100 Mark 2 wide angle. How does that sound? I am concerned about stopping up too much given that DoF at F2 is very very shallow. Then again, F8 may be too dark and require too much ISO or too slow shutter. So maybe shutter priority is the way to go. What shutter is fast enough to prevent motion blur??

Thanks!