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BDSC

Auto White Balance Question?

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My current housing does not allow me to do MWB with my video camera. I think I have read (and it may very well have been here somewhere) that you can achieve something similar if you hold a white board/slate in front of your camera at depth and then turn the camera off and back on again. I'm guess the idea is that the camera does a AWB when the camera is turned on.

 

So.......does AWB actually work that way in a video camera and would this be effective at depth? I have no idea so I ask the experts on here.

 

Thanks,

 

BDSC

Edited by BDSC

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The auto setting changes the WB in the camera depending on the light source, It's automatic...... a constant effort by the camera to adapt to the spectrum it "sees"

If you hold up a white slate the camera will adapt to it, if you take away the slate the camera will adapt to what is now in view.

As far as I know the slate only make a temporary change to the WB and by turning off and on with the slate you only trick the camera temporarily and it then reverts to the available light source once the slate is removed.

There is a depth of water where the red filter replaces the same amount of red light as the water column absorbs, different for every place, time of day and other factors, usually around the 8-10 m range at least in blue tropical water. It's not exact and it's not perfect but there you go.

Is there a housing available for your make of camera that does allow Manual WB?

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Thanks for the feedback Richard! What you are saying makes perfect sense. I hadn't thought about the fact that it's auto means it can be changing all the time. So the white slate thing would work only briefly.

 

I have an older TopDawg setup with a Sony DCR-HC42. It's my first setup and I bought it used for a great price. I have had it on two trips now with a third coming up in May to Little Cayman. I've been diving for 18 years but just got into video and I love it. So after this trip, I may start looking to upgrade my entire system and go the HD route.

 

I am thinking about a L&M system. Their 2009 Stingray model is designed to allow a number of current and future Sony HD camcorders but you lose the ability to do MWB. So it's a trade off. I was just wondering if there was a way to accomplish MWB in the cameras by fooling it but it looks like I would be the one getting fooled if I think that. Of course they have the Bluefin which allows for MWB but the housings are camera specific. I just wonder in the clear tropical waters where I dive how important MWB is and can you come close to the same results by correcting when you edit.

 

So I'm just trying to learn all I can before I invest some real bucks into a more modern system with all the bells and whistles. And, of course, there is the debate of a film based camera vs hard drive. So much to think about!

 

Thanks again for your feedback. I really appreciate it.

 

Ashley Perry

Edited by BDSC

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Hi Ashley, I'm afraid it's mostly like that, if you want a camera/housing combination that allows you to access most of the cameras manual functions you need a housing that's specific to the camera or one that costs a little more than the basic models available.

Using MWB underwater makes a huge difference, all the difference IMO, replacing the colours that are lost. Lights will only illuminate the close range subjects so don't expect that to solve your issues. A wide angle lens also helps hugely as the less water inbetween you and the subject, the better the clarity and colour.

It's just down to you to decide whether or not you want to make the investment in a new system that is the next step onwards and upwards than your current one.

I can advocate Gates whole heartedly as mine has served me very well and stood up to a working environment very well.

Have fun in LC, If you are diving at the Beach Resort say hello to Dottie, Ron, Ozzy Ben, Video Ben, Jeremy, Kimberley and all the gang there for me.

Happy shooting

Richard

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From everything I keep reading you're spot on with the MWB thing so I'm leaning toward going in that direction. I'll probably start looking a little more serious after my trip in a few weeks. I've also seen some really good deals on some little used equipment that have all the advanced features. It seems like when the new models come out some people like to get the latest and greatest and get rid of some really good equipment that has hardly been used so that may be an option.

 

I'll be sure to say hello to the group for you. That's where we'll be staying.

 

Ashley

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Research Research Research! I can't advocate it enough!

Happy Shooting

Richard

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I tested this with my HC3 some time ago, as my Seatool housing does not provide access to MWB. With the camera in AUTO, I turned it on inside -- looked good -- and then took it outside. Bluish, as you'd expect. Turned the camera off and back on -- WB was immediately correct -- and then took it inside. Looked reddish, again as you'd expect.

 

Based on that, I've been turning it off and back on as I change depth, with a slate in frame when I power up. This is in addition to using the red filter below about 25 ft. I can't say definitively if it makes a huge difference, but I believe in it anyway.

 

Additionally, and more significantly, I use the WB eyedropper tool in FCP when I edit, and it makes all the difference in the world. It really helps if you actually record your slate at various depths to provide a white reference for the eyedropper. Adjusting white balance when color correcting in post shifts the spectrum for everything in the shot, so it IN THEORY will give you colors nearly as accurate as having done a manual WB on site. Some will argue, though, that you really can't recover colors that you didn't shoot and that there's no substitute for actually white balancing. I'm just recommending alternatives if your housing doesn't allow it.

 

Brett Kotheimer

Vimeo.com/bkotheimer/videos

Edited by Kotheimer

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Thanks Brett!

 

I may give that a try then. I'll just get me a white slate and see what happens. If I can remember, I'll shoot identical scenes using just the AWB and then doing it with the turn on - turn off method. It will be interesting to see the results.

 

Ashley

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