Sony White Balance for UW?

[sparklehorse 0]

Hello again,

I'd like to conduct an informal poll on the White Balance settings you folks like to use underwater with your Sonys. I did a lot of underwater photography back in the days of film, but have not yet shot any digital underwater, and figuring out white balance settings is a major concern for me right now. I'm headed to Mexico next week with my a6300, but I think all the Sony Full Frame and Mirrorless bodies from the last couple of years are fairly similar in terms of their white balance characteristics. I've read so many posts on this WB topic recently that my brain is just fried. Some say you should take a custom white balance every 10-15 feet, some say if you do this the Sonys throw an error because the reading will be outside the 9900k color temp limit, some say just set the WB manually to 9900k and add a +7 M tint, some say Underwater Auto White Balance works well enough, some say just Auto White Balance is fine, one guy posted PDFs of A4 size color swatches he made that simulate UW color cast, and that you can print those out and take a custom WB reading from them in daylight. Wow, so many freaking choices! Last time I took photos underwater the only 'White Balance' options were either Kodachrome or Fuji .

 

I'll be shooting video as well as stills, using Sony's 10-18mm wide angle zoom. I'll be diving on the Pacific side of Mexico. I expect visibility of only about 30-40 feet.

 

For video I have a Kraken Hydra 2000 lumen video light mounted on the cold shoe of my Nauticam housing on a 4 inch flexi arm. My plan was to use Sony's Underwater White Balance for video, because I'm afraid if I set a custom White Balance for the ambient light, anything illuminated by the light will be too red. Is this a valid concern? But I've read that Auto WB can change the color cast of your video abruptly and is best avoided. I think I'm going to shoot XACV-S in 4k, but I'd rather not have to do any color grading in post.

 

What settings do you folks like to use for WB for UW video with a light?

 

For stills I'll have two Sea & Sea YS-D2 strobes with diffusers. My plan for stills is to use Sony's Flash White Balance setting. That should give me good color for whatever is illuminated by the flash, but I'm not sure how the background water column is going to look. I will be shooting RAW, so I'm thinking I'll have enough latitude to adjust the background water to a color that is pleasing if need be. Does this sound like a good plan?

 

What WB setting do you like to use on your Sony for Wide Angle stills with strobes?

 

One other quick question - do you think I'll need to kill the video light prior to shooting a still? I'm concerned it could cast unwanted shadows or add a color cast, but maybe the strobe will be so much brighter it won't matter.

 

Thanks for all your help guys and gals!

Edited December 4, 2017 by sparklehorse

[Barmaglot 250]

I'm very new, only done one trip with a camera so far, but I tried setting manual white balance with my A6300 and it just errored out every time. I shot mostly stills though, with Archon D36V lights, and used RAW with processing in Capture One Express to fix the colors - spot white balance ended up mostly in 11000K-13000K range, so it makes sense that the camera threw errors, being limited to 9900K.

[Thrawn 0]

In my NEX-5N and NEX-6, white balance errors in the display but it actually seems to go beyond 9900K. I haven't really tested it out with my new A6300 yet.

 

Note: I always use a red filter.. usually a plastic filter taken from an SRP GoPro URPRO SWCY pack

[sparklehorse 0]

<snip> I always use a red filter.. usually a plastic filter taken from an SRP GoPro URPRO SWCY pack

Thanks for your reply. Are you using any artificial lighting, or shooting with only ambient light? I'm sure the red filter helps get pleasing color for ambient light, but I'd be concerned that anything illuminated by my video light or strobe would be too red if I used a filter. I've seen folks mention using a cyan filter, I assume on their video light or possibly on their strobe. I'm guessing this is to help tone down the red hue caused by a red filter. Not sure I'd want to go that way unless it's truly necessary.

Edited December 5, 2017 by sparklehorse

[dreifish 361]

For stills, don't worry about it. Just shoot raw and fix it later with the white balance tool in post. If you really must, you can just set a WB of 5500k, which roughly matches the temperature of the YS-D2 strobes. That should give you a reasonably nice water column with a well illuminated foreground subject right off the bat, even in JPGs. Basically, treat it as shooting film with daylight-balanced film but with the option of later adjusting that in post.

 

For wide angle video, your light is probably way too weak to make much of a difference, to be honest. There are no real good options here -- stick to shooting video only in 10 meters of depth or less when there is plenty of ambient light. In those circumstances, I personally find that the Underwater Auto White Balance mode gives pretty good results, so I'd try that first and review your videos and see how you feel. Yes, the white balance can change in the middle of a clip, so some of your clips may end up unusable unless broken into chunks. In really shallow water (less then 5 meters) you should also be able to set a custom white balance off a grey slate or your palm even without a red filter and get decent results. My suggestion is that you experiment with those two options and see what you like.

[sparklehorse 0]

For stills, don't worry about it. Just shoot raw and fix it later with the white balance tool in post. If you really must, you can just set a WB of 5500k, which roughly matches the temperature of the YS-D2 strobes. That should give you a reasonably nice water column with a well illuminated foreground subject right off the bat, even in JPGs. Basically, treat it as shooting film with daylight-balanced film but with the option of later adjusting that in post.

 

For wide angle video, your light is probably way too weak to make much of a difference, to be honest. There are no real good options here -- stick to shooting video only in 10 meters of depth or less when there is plenty of ambient light. In those circumstances, I personally find that the Underwater Auto White Balance mode gives pretty good results, so I'd try that first and review your videos and see how you feel. Yes, the white balance can change in the middle of a clip, so some of your clips may end up unusable unless broken into chunks. In really shallow water (less then 5 meters) you should also be able to set a custom white balance off a grey slate or your palm even without a red filter and get decent results. My suggestion is that you experiment with those two options and see what you like.

Thank you dreifish, that's very helpful. I don't anticipate shooting much video in shallow water. I'll be diving at the Marietas Islands, and from what I gather a typical boat dive there is between 40-70 feet. I know the 2000 lumen Hydra is not a lot of light to work with, but the Sony a6300 seems to be capable of shooting decent video at ISO 3200 or even ISO 6400. So I wasn't too worried about being under-gunned with the light, but I could be way off on that. I'll probably shoot video at 1/60th sec with an aperture of f/5.6, maybe f/4.0. I'm just hoping to get nice color on things like morays, or other fish or coral from a few feet away. Do you think I'd need more lumens at a depth of, let's say 60 feet?

 

Also, I am concerned about backscatter from this video light. I'll have the Hydra light mounted on a 4 inch flexi arm attached to the cold shoe. I was told at the LDS where I bought the light that that setup shouldn't cause much backscatter for video, but what do you folks think?

 

Thanks again for all the help!!

Edited December 7, 2017 by sparklehorse

[Barmaglot 250]

This is straight out of camera, no processing, underwater auto white balance, A6300 with 16-50mm lens, Meikon housing with Meikon wet dome, two Archon D36V lights: https://youtu.be/QQfYNH3b2Wc

[dreifish 361]

Thank you dreifish, that's very helpful. I don't anticipate shooting much video in shallow water. I'll be diving at the Marietas Islands, and from what I gather a typical boat dive there is between 40-70 feet. I know the 2000 lumen Hydra is not a lot of light to work with, but the Sony a6300 seems to be capable of shooting decent video at ISO 3200 or even ISO 6400. So I wasn't too worried about being under-gunned with the light, but I could be way off on that. I'll probably shoot video at 1/60th sec with an aperture of f/5.6, maybe f/4.0. I'm just hoping to get nice color on things like morays, or other fish or coral from a few feet away. Do you think I'd need more lumens at a depth of, let's say 60 feet?

 

Also, I am concerned about backscatter from this video light. I'll have the Hydra light mounted on a 4 inch flexi arm attached to the cold shoe. I was told at the LDS where I bought the light that that setup shouldn't cause much backscatter for video, but what do you folks think?

 

Thanks again for all the help!!

 

The issue isn't the sensitivity of the camera -- it's the ratio between the strength of your video light and the strength of the ambient light. If the ambient light is very strong (say, at midday, or in shallow water), then you have to expose for that -- you shoot at ISO 100, because ISO 3200 or 6400 would just end up with everything being blown out. The problem is that your light is nowhere near as powerful as the sun in these conditions, so even if you have it turned on, it's not going to restore much color. The cool ambient light is going to make up the majority of your exposure.

 

The reverse is true at night when there is no sunlight to outcompete, or just after sunrise/just before sunset, or the deeper you go. Then, you can expose for the strength of your light, and the weak ambient light won't blow everything out.

 

Backscatter is a function of how many particles there are in the water and the angle of your beam. This article is a good starting point to understand what causes backscatter and how to best position your lights to minimize it (note, you'll never be able to eliminate it. If there's particles in the same focal plane as your subject, they will be lit up by your light--or the sun, for that matter)

[Thrawn 0]

Forgot to return to this thread. Been to 2 dive trips since then..

 

I don't use lights at all during the day, ambient light makes it pretty pointless.. particularly as I prefer to shoot larger scenes (in video).

 

The A6300 definitely white balances beyond 9900K (throwns an error, just like NEX-6). I use my SRP red filter.

 

In terms of white balance consistency, the custom white balance settings is not as good as my old NEX-6 in nailing good results. Its a bit of a hit and miss, sometimes it nails it really well.

 

Underwater auto white balance produces inconsistent results.. even worse.

 

The 4K 100 Mbit produces a lot of detail.. a big improvement from my NEX-6 as expected which tends to lose detail in complex scenes due to low bitrate. Low light capability feels like 1-stop better, which helps quite a bit in deeper conditions. Noise isn't at all an issue anymore. The lack of 60fps is annoying though.. 25-fps means that quick movements looks terrible. You really need to be really still and smooth to get good results.