Deep white balance and gain

Have you quantified what dB level of gain starts to give you unacceptable noise?

Nick,

My Z is set up with the gain settings:

L - 0

M - 6

H - 12

15 and above start giving noise in many situations. Quicktime already freaks out the Gamma curves in many shots but with 15dB the whites starts getting pretty blown out.

Cheers,

Mark.

Hello Mark!!

This is David and Luisa from Gran Canaria! She is right here telling me to say hello and a lot of good things about thanking you for the way you treated us in Palau (although there is never enough beer with that spicy sushi! ).

Here are some pics that I don´t know if you saw them

http://wetpixel.com/forums/index.php?showtopic=17477

http://wetpixel.com/forums/index.php?showtopic=17379

http://wetpixel.com/forums/index.php?showtopic=17384

http://wetpixel.com/forums/index.php?showtopic=16683

Congratulations for your new website and really looking forward to come back or see you again anywhere.

PS: That RED camera sure looks promising

PS2: oooopss sorry for the offtopic....

Mark that's interesting. Can you access the 3-position gain switch underwater on the Gates or is it like the L&M where it's either pick-a-value-and-stick-to-it or auto?

Can't access it on the L&M Bluefin. I therefore have it limited to 12dB in a picture profile that I run all the time (also includes +2 colour), but the noise is quite severe at 12dB. Not the nasty horizontal lines but quite a lot of grain.

Couldn't you use CC filter and MWB a lot deeper than 8-12m and still stay within a fairly noise-free gain setting? Or is your reasoning to avoid a big "jump" in colour balance that you'd get if you switched over deeper?

I did a load of white balance tests on my last trip using Expodisc and other methods, and these also show the gain/noise. Some very interesting results. I will post these up after I've finished archiving my stock.

Hi Nick,

Yes I do have manual control of the gain presets with the Gates. When locked at zero dB on a really sunny day and with the Iris locked it makes for some fantastic images - (this one has been adjusted for the web so it does look a bit off).

I never use picture profile, I prefer it raw and if needed will adjust in post. My saving grace is Palau, this place is so frikkin' diverse that even on rainy days there is something cool to dive. Just taken stock of some new shiny Squid 250's from Green Force too so planning to test out composition using a Sony wide lens instead of the SWP44 monster.

As for WB at depth I really am not a fan of noise caused by the cam having to work harder through the CC filter at depth. It darkens the image and shouts with all the noise in the image. Thats my personal 2c. My attitude towards filming people here in Palau is also maybe different than that of dedicated video services elsewhere. I intend to go on each dive with a view to collecting stock. I also film for about 25% of the dive some of the divers on the dive with me and then offer that up for grabs if people like. With the clarity of HDV in Palau waters its a fair trade off as people get more wildlife and less of themselves. I then obviously like to get as much clear and noise free footage on each dive hence the policy with regards to the CC use.

Hope this helps.

Hola David y Luisa, espero que todo era muy agredable en su viaje. Visto, si, los images, muy buenos. Espero tambien que podemos acer mas inmersiones en el futuro. Suerte con todo y abrazos mi amigo.

Mark.

Gotta do Palau again one day. Was there without a camera in '95 but couldn't get down for half the trip because of a stinking head cold. A couple of cracking dips at Blue Corner though. Were you there then?

Mark, you're shooting in a similar way to me. Stock foremost but getting enough of the divers to make sales to them too. Indeed I just spent 4 days archiving stock from a single liveaboard trip, trying to think of the future rather than jumping back on the boat to make a fast buck.

With each trip I tend to be flipping OUT the CC filter shallower and shallower, so perhaps I'll end up doing the same as you. But you know, the divemasters on the boat look at my green clips from 30m and ask me why I bothered getting a new camera because the footage from the old one (the VX2K which I white balanced with CC filter at all depths regardless of noise) looked better.

This issue of whether to manually white balance or not in that 10-30m range really is a tricky one. Your turtle looks great but in some moods I might be yearning for more reds/oranges.

With a cheap camera, footage that hasn't been manually white balanced just looks a crappy washed out greenish blue, like it was done with a cheap camera. With a good camera like ours however, it can have that quality "Blue Planet" look if focus, exposure etc. are right and it matches the adjacent footage, and it's viewed on good equipment.

Quick question Mark... below 12m are you using auto white balance, daylight preset, or another WB preset?

As for WB at depth I really am not a fan of noise caused by the cam having to work harder through the CC filter at depth. It darkens the image and shouts with all the noise in the image. Thats my personal 2c. My attitude towards filming people here in Palau is also maybe different than that of dedicated video services elsewhere. I intend to go on each dive with a view to collecting stock. I also film for about 25% of the dive some of the divers on the dive with me and then offer that up for grabs if people like. With the clarity of HDV in Palau waters its a fair trade off as people get more wildlife and less of themselves. I then obviously like to get as much clear and noise free footage on each dive hence the policy with regards to the CC use.

 

Mark.

Great turtle shot. Aren't those critters a videographers delight. They're co-operative, slow, distinctly shaped, do interesting stuff, often have interesting expressions on their face and always get an "ahhhh" from the audience. Next month I'll be in Sipadan. Instead of complaining about "too many damn turtles", I plan to come back with lots of playful turtle footage.

I am pleased to hear from a another UW videographer who does not like the CC filter. I have not used one for the last 12 months. But I was starting to wonder if I was missing the point.

My theory goes like this: a filter can not add anything, it can only take something away. In the case of the red CC filter, it takes away all other colours so that the proportion of red looks greater. There is not more red, just less of everything else, right? This looks better when played back from the camera or if you playback unedited footage. But, if you always edit your footage (e.g. Final Cut Pro), then all that filter is doing is giving you less stuff to edit. You can always do everything that the CC filter does in the edit, and do it with a lot more precision and control, right?

Is this right? Or am I missing something?

What do others do?

Regards

Peter

It works to a certain point with out a filter but I have material for sure that I can not fix up on the NLE that was shot without a filter. If it was the case then why would we bother to manual white balance as well?

Nick you can also turn on/off and adjust the db gain on the Phenom while underwater.

Quick question Mark... below 12m are you using auto white balance, daylight preset, or another WB preset?

Until 8 or 12m I am manually white balancing using the CC filter when sun is good. If cloudy I am going to daylight preset with the CC in place. If too cloudy I go for daylight preset with no CC. Below 12m I have set the B preset WB option to the white balance of my Squid 250's.

The VX2/100 against the Z1 obviously wins hands down in the lux wars. Personally I really am not a fan of shallow water images where all reefs look a light tan color and the blues are a very faint hint of maroon. That said they are great for the home DVD souvenir etc as the colors are quite vivid and could very well entice non divers to at least take a splash to see for themselves. Swanage pier may be a bit different from Palau though on a discover experience !!

The Z1 is not the perfect solution, thats why nutcases like us keep shelling out huge sums of cash to stay up to date with the demands of TV though. mind you on that note I have been talking with the BBC NHU about South Pacific, a pretty big project due to start next year......."No HDV footage allowed" and that is from the executive producer.

So every time we upgrade so do the stipulations for footage requirements, hence the RED decision. It may be a bit of cash to lay out at the outset but after that I will never have to 'take one in the plums' when people say "yeah, but it needs to be uncompressed 4:4:4 HD / 1080P / 1080i / 720P / 2k / 4k......". GOTCHA. If after that there dawns a new format that everyone switches too I'm gonna sell the lot, paint a peacock on my forehead, prance up and down Oxford Street whilst reciting my profound love for Richmond Tea biscuits dipped in Starbucks Coffee !! ha Cuckoo ......

Wags, I am using a filter down to max 8 or 12m depending on the turbidity of the water on any given day. After that I am using the Squid 250's to fill foreground elements of composition. With the Flexi III battery packs I get 3 hours of 250w per head at 3800k. Looks sweet and gives me good stuff for stock. I'll post a few images within the week.

Cheers,

Mark.

I'm gonna sell the lot, paint a peacock on my forehead, prance up and down Oxford Street whilst reciting my profound love for Richmond Tea biscuits dipped in Starbucks Coffee !! ha Cuckoo ......

Looking forward to more stills Mark.

Peter, I'm with Wags on this one. If footage is too monochrome you simply can't restore a broad spectrum of colour in post. You need to record enough differences in chroma to be able to do that and at depth you need to do that with manually white balancing or with lights.

On the subject of turtles, here's a grab from some footage shot with my old 3CCD Panasonic DX110B which I couldn't white balance underwater. It's from about 20m at Phi Phi Island. The first image is without correction. But because I'd used the CC filter there's just enough colour information for me to be able to adjust it (see 2nd image) to match later balanced turtle footage shot with my VX2K. This is about the most colour correction I've ever been able to get away with. Without using the filter I really think it wouldn't have been possible.

This was just using the Vegas colour corrector filter. There are more advanced ways to "paint" in colour but these take a lonnnnnng time.

Peter, I'm with Wags on this one. If footage is too monochrome you simply can't restore a broad spectrum of colour in post. You need to record enough differences in chroma to be able to do that and at depth you need to do that with manually white balancing or with lights.

I guess that is one reason why the UR Pro filter does not do much for me. I shoot a lot of reef footage with the 2 HID lights running. If you do that with the filter in, anything within 3 meters looks too red.

On my next dives, I plan to do more open water stuff, hopefully with some larger critters. I'll use the wide-angle lens and leave the lights off. Then the UR-Pro might be useful unless I am below 20 meters. I also plan to MWB at major depth increments.

Do have problems with the "greeness" of the Andaman Sea during this season? I just returned from South Andaman. The water always looked green. The raw video footage looks even greener. I have been able to pull it back to blue in FCP but it was a challenge. I am wondering if the "URPRO GR" filter might not be helpful during the plankton season? Have you ever tried one?

Regards

Peter

Well Peter, you could still leave the filter in when your lights are on and then manually white balance on something a bit of distance away (such as white gaffer tape on a fin) to knock back the red. I believe others on the forum have done this. Didn't really work for me however when I tried it briefly. If my lights are on my filter's out and I suggest you do the same.

Yes, the green water can be problematic. Even worse in Burma. I'm collecting quite a kaleidoscope of different coloured footage at the moment. Check out my Myanmar Magic video and you'll see some seriously green footage. I just tend to go with it when it's that green, because that's how it is.

Somewhere in the deep dark distant past I did try a "green water filter". It wasn't a UR-Pro but a magenta coloured glass screw on filter for my Panasonic DX110B. I don't have any results to show you but I remember my conclusion being that it isn't even for "green" Andaman water, it's really only for super-green inland sites.

It might be worth a try, but those UR-Pros are difficult to get hold of here in Thailand and expensive (I actually gave up trying to get one recently after numerous emails and calls with them). They also make (made) another model which was somewhere between the blue and green water filters. A bit of research should turn that up.

Well Peter, you could still leave the filter in when your lights are on and then manually white balance on something a bit of distance away (such as white gaffer tape on a fin) to knock back the red. I believe others on the forum have done this. Didn't really work for me however when I tried it briefly. If my lights are on my filter's out and I suggest you do the same.

Next trip (April - Sipadan) , that's what I am going to do. I'll only use the red filter for WA, open water shots, lights off, and MWB off a large slate that I keep in my pocket. For reef stuff, I'll stick to my current approach of filter out, lights on and shoot close. But I also plan to be a bit more diligent at doing the MWB more often. Trouble is, when the action is happening, all my good plans and intentions dissolve in the water and float away on the current... <S>

I just tend to go with it when it's that green, because that's how it is.

I agree with you. We should not be forcing our footage to something unreal. But I do find that audiences react better to UW footage that is blue rather than green...

Hey Peter, while searching for something else I found this thread about white balance in green water. Might be worth a read.

Enjoy Sipadan. Jealous about that. Was there in 2000 without camera unfortunately but I remember awesome turtles and humphead parrotfish schools amongst other things.

I've found a few times that I W/B thru the filter then flip it off and it seems to do the trick..Adds red, takes a bit off.

Like others I am relying on 'post' to sort out the majority of the Correction..This is in 5-6M of freshwater 'greeny blue' and as silty as it comes.

In my domain it can change a bit more drastically..!!!

Dive safe

DeanB