filter for underwater shooting?

[falcon418]

Can anyone with underwater experience tell me if I need a polorizing filter or any other type of filter?

We'll be shooting (HD 720pn) in pretty clear sea water no deeper than 25 feet.

Thanks,

[SomewhereinLA]

You'll find all your answers here:

http://www.scubaboard.com/forumdisplay.php?f=92

[MarkS22]

I've done a bit of underwater photography near the surface (with Ewa-Marine bags) in Bahamas and Grand Cayman. With very clear water and shallow depths, you'll probably be fine without a filter if you mind your white balance.

Keep in mind that the level of color shift is affected by the depth, water's clarity, AND the subject's distance from the camera. You'll also lose contrast in a similar manner. If you stay 5-10 feet or so from the surface and the subject is only a few feet from the camera, you'll only need minimal correction. However, if you're closer to 20 feet depth and the subject is another 20 feet away, you'll definitely start losing the warmer colors and contrast... because your light is now being filtered 20 feet vertically PLUS 20 feet horizontally. This is where you might want to consider a red-shifting underwater color filter.

Without knowing all the conditions or your subject, I'd imagine you should be fine shooting a white card at the depth and distance from your subject and (if needed) tweaking the rest in post. I've also seen some good results using a white balance lens cover, like the ExpoDisc, for close-range underwater video.

Alternatively, you can look into underwater halogen lighting. This can restore some colors to your close subjects because the light is only going through a few feet of water.

In terms of a polarizer, that would only be helpful if you plan on shooting from above and down into the water. It'll cut down on the reflections on the surface. (If you were using underwater lighting, some photographers polarize the light source, then use a second polarizing filter on your lens to cross-polarize and minimize bright debris ruining your shot.)

Finally, try to shoot with the sun directly overhead (around noon). You know, the time that the beach stuff on dry land looks the worst.

Hope that helps a bit... good luck!

[indigo]

Out Of interest what housing are you using? do you have a link?
Cheers

Indy....

[falcon418]

Since we are shooting in relatively shallow water we chose to go with the Epic Pro HD. You can find it at www.epiccam.com.

And thanks everybody for the informative answers.

[BobDiaz]

At around 20 feet or less, no problem...

However the deeper you go, the more you loose the reds, yellows, ... blue is the last to go. For those who must shoot below 20 feet, some sort of BRIGHT underwater video light is a must. Without a light, footage at 60 feet looks sick.

The under water light needs to be in a second underwater housing. It would be best to have the light at an angle (like 45 degrees) to the camera to avoid things in the watter showing up as bright little spots. Having a second light helps too.

The difference between having a light and not having one (at 30 feet or more) really stands out. You may want to use one of the LED lights and have a second diver deal with the light.

I shot Super 8 movies underwater for several years, so I've see the difference a light makes.


Bob Diaz

[Justin Kuhn]

Since we are shooting in relatively shallow water we chose to go with the Epic Pro HD. You can find it at www.epiccam.com.

And thanks everybody for the informative answers.

What camera were you shooting on? I couldn't find the HVX on their list of supported cameras, which was disapointing--I've been looking into getting a dive housing.

[falcon418]

HVX 200. Their website is not up to date. If you email them directly, they will reply and tell you that it will fit in their Epic HD Pro model which is what we've ordered. Good luck.
Interestingly enough, I just thought of a question I did not ask them which is how do you achieve negative buoyancy. They don't say anything about weights on the website.

[cici]

You may want to use one of the LED lights and have a second diver deal with the light.



Sorry, but I DON'T recommend LED lights at all for underwater videography. The LED light has too many disadvantages - first of all its color temperature. As YELLOW disappears as the first color underwater, you'll need a yellowish light for videography - even for night-dives. There is a big difference between diver's lamps and underwater videolamps. One difference is the color temperature as I explained and another difference is the shape of the light spot. It's much smoother with videolamps that's why they are more expensive than diver's lamps/torches. Diver's lamps often have one hotspot in the middle of the large spot that would look very ugly in videos...

Regarding the filters: I DON'T use any filter - I use only whitebalance and the rest I do with my PC. With the PC your blue water will stay blue and won't get purple... (secondary color correction). Filters for underwatervideo cost more than "normal" redish color filters cost. It's just commercials... and what for? You would need each time another redfilter depending on how deep you dive, how warm the water is, how high the degree of salt is, how much plankton there is in the water, what colors the background and bottom have etc. etc. so a filter is only a SUPPORT for whitebalance and color correction in postproduction. That's why I save the money... ;) The PC is stron enough to add as much red and yellow as you want to the regions that YOU want and not for the whole picture as a filter does, including the water or a blue fish...

Here are some framegrabs in PAL of underwatervideos I made 2 years ago with a Sony TRV900. There's NO COLORCORRECTION and NO RED FILTER in it. Only the white balance and one lamp for close-up. You'll see also a comparision for video WITH or WITHOUT the lamp.

LINK1 (http://digitalvideoschnitt.de/forum/showroom/40678-beispielbilder-unterwasser.html)

and some framegrabs even WITHOUT lamp, redfilter, etc.

LINK2 (http://digitalvideoschnitt.de/forum/showroom/25354-standbilder-aus-meinen-videos.html)

But for best results I'd take the time and color correct those videos (first of all the skin of the diver and white spots as on manta rays etc.). The examples are just to show that a lamp and some whitebalance (with a blue-green, NOT blue chart) make colors underwater already 95% natural. The other 5% are colorcorrection - so you come to 100% without using a filter.

I almost forgot: filters that you can't pivot insinde in or out (like red filters inside the housing) must be screwed on and off DURING the dive. Because for the first inches and feet - e.g. when you film how the divers get into water - a red filter would cause very ugly pictures, especially if you film towards the direction of the sun. Another reason why redfilters are dispensable. Save gear if you can ;) You'll save rinsing, cleaning, money, screwing etc. also....