Sony a7s II underwater use -- All parameters

Thanks Dreifish.

 

I have heard many negative things about the camera. I was very disappointed in the magenta cast of my first films. I had been using manual white balance. I was using a magic filter. I am wondering why I purchased the camera, and the housing, if the white balance was so unpredictable and low quality.

 

I am hoping that I may be able to meet the challenges. I am going to do some tests on my next and will try the underwater auto white balance, and perhaps discard the filter, so that I can use the lights, without a filter.

 

I will let the people on this thread now what happens on my next adventure.

 

I appreciate the time you took to answer my question.

You have to know that you won't have nice colour at every time. I know Canon users who dont have nice colours. It depends of many things. Like sun position, water colous, visibility, etc....

Lower than 20m I do not think about it, I just get lights and AWB with A+3, M+3.

Maybe you won't get the perfect shot but you allways have the VECTORCOSPE and WAVEFOR to work with it....

UPDATE TO ALL:

I am back from my Sea of Cortez trip and here are the results.

1. Yes I was trying too many things, as Taxi Driver said. Thus, I did not experiment with picture profiles. Shot with no picture profile for video and this also facilitates the use of the camera for RAW still photography.

2. I was never able to achieve a custom white balance. I tried a white slate, my hand, the white sand, and at about 30 feet, where I was experimenting, it always came back "White balance error." This is as Dustin says. And this is not what the expert at Backscater said. He advised me to always take a custom white balance with this camera, and in Cozumel, I was following his advice pretty strictly, and it was yielding the poor results that are apparent in my first test film, which showed all my dirty laundry for the world to see. On this trip, in the Sea of Cortez (where the water was a different color and the temperature was 86 degrees) I was using a magic filter, and then I tried automatic underwater white balance, and things turned out exactly as Dreifish says. Sometimes the colors were awesome, and sometimes terribile, and sometimes things switched in mid stream. It did depend on the lighting conditions at the time. I will post some of the results. We were also experimenting with a GoPro using the Backscatter filters, and it is interesting indeed to see the way the white balance is handled on the GoPro as compared to the Sony.

3. Light gathering ability. The main thing I noticed was the awesome light gathering ability of the Sony a7s II was evident. I was able to get passable results, using available light only, even at 30 or 40 feet. The professionals who always use bright strobes, for perfect white balance and huge depth of field, would not be impressed. However, it never looks like that in reality. It is an artificial way to see things. I rather liked seeing things as they actually are, with the light filtering through the water and a bit of a shadow from the point source of the sun, rather than a completely diffused light source like a strobe illuminating a macro subject. Still, even there with the available light, I was using a magic filter and the auto underwater white balance.

Next trip, in 3 weeks, I will see if the camera can handle things without a magic filter, using the underwater auto white balance. This would allow me to use video lights and ambient light on the same dive. Not supposed to be able to do that, but perhaps that statement only applies to custom white balance. Maybe not to auto underwater white balance. My bet, however, is you still have to use the filter.

Again, thank you for everyone's responses. I am working on a film that will illustrate my experiences, as well as tell the story of your typical dive trip out of Phoenix, Arizona, with all the various and sundry characters, shady and wealthy and grown up and kids, all thrown together suddenly for a diving adventure.

George Paul

Waiting results. In 2 weeks will be in Cabo de Palos trying new things....

Thanks George for the update. In my case, I can only try the cam during my diving trip next month. As I don't want to risk it, I decided to shoot video using Picture Profile 7 (S-Log2 + S-Gamut) to grade the colors later in Adobe Premiere and Speed Grade. Not an expert in doing so, but there are good tutorials online to help me through the process. This way if the cam WB fails me, which likely it will, I will have the liberty always to correct the colors after the trip. For stills, I always shoot uncompressed RAW, so there is no problem here. Either Photoshop or Lightroom will do great job in correcting the image exposure, brightness, contrast and colors.

From the accumulated articles and videos I researched concerning the best cam setting in preparation for the trip, I have set my cam as follows:

For stills:

1. Manual mode, uncompressed Raw, AR 3:2. A good exposure starting point, depending on ambient light, is setting the aperture to f/8 and shutter speed to 1/125s, ISO 100-200

2. Continuous shooting drive mode, and continuous AF. Focus area is center

3. Metering mode Spot

4. WB Auto

5. Will use two Sea and Sea YS-D1 strobes, manual mode, so I chose second curtain shutter by turning off the e-Front Curtain Shutter

For Movies:

1. Assigned custom dial 1 for movies

2. File format XAVC S 4K, 24p 100M with APS-C/super 35mm turned off to get only a full frame shooting. I had to buy SanDisk 64GB Extreme Pro 280MB/s memory cards to shoot 24p 100M videos

3. Continuous shooting drive mode, and continuous AF. Focus area is center

4. Metering mode Center

5. Exposure step set to 0.3EV in order to set the shutter speed to 1/50s

6. Picture Profile set to PP7 (S-Log2 + S Gamut)

7. Movie Button = Always

8. WB Auto, though I might adjust the A-B value to A2 to force more red

9. I will use two Fisheye FIX Aquavolt 3500 LED video lights mounted with the strobes using the triple clamps

To conserve battery life as possible:

1. AF illuminator turned off

2. Pre-AF turned off

3. Assigned Deactivate Monitor to custom button 4

4. WiFi disabled by turning on Airplane Mode

5. Monitor brightness set to Manual at 0, noting that I disabled the view finder

6. Display quality set to Standard

7. Power Save Start Time = 10 Sec

These are only my initial preparation which will require indeed fine tuning once in the water and depending on many lighting and mood circumstances, noting that my cam is A7R II, a sister to the A7S II but with a bit different video shooting quality and light performance.

https://vimeo.com/169073510

https://vimeo.com/165307362

https://vimeo.com/164532144

This are my first 3 videos with A7RII. Shooted right from the box. Water conditions awfull except the swimming pool jejeje. Will try to improve step by step...

Thank you for sharing TaxiDiver. Those are actually great videos, especially for an out of the box first time experience. I hope the diver in the pool (00:53) is OK though

Was steady shot on? What was your lens?

The diver is ok hehehe. That was a Discover Scuba for Dawn Sindrome kids and I had a great day with them.

Steady allways on. Lens FE 16-35.

No lights(only on second video). AWB (Color Matrix A+3, M+4).

Thanks to you two for posting. I appreciate it and will digest your posts, and films, and respond. Since Taxidiver was kind enough to post his films, I thought I would throw together some of the recent 4K footage shot in the Gulf of California. I show two clips twice to illustrate a comparison of Raw footage and some post processing (not touting it, just showing you how footage shot without a picture profile can be edited for color correction in Premiere Pro).

Ammar: You comprehensive post is awesome. In particular I would like to get back to you on the picture profile issue.

Thanks,

GLP

Beautiful video George. The blue is well, blue. What did you different this time than your first video test that had a magenta tone?

Nice colours. This is the RAW or the CORRECTED ???

TaxiDiver:

On the test movie I supplied both RAW and Corrected, one after the other, so that people could compare. I did that with 2 clips, so you will see 4 clips in the little movie -- two versions of each file.

Ok I got it. On second clip when you correct you push up magenta too much on whites. You can see it on ths sun ball.

Beautiful video George. The blue is well, blue. What did you different this time than your first video test that had a magenta tone?

Thanks Ammar:

On the first video with the magenta cast, I was trying my best to do a custom white balance, at 60 or 70 feet, and now I know that you really can't do that with this camera. In addition, I think I did the balance and then ascended a little, so whatever I did, was done at 15 to 20 feet deeper than where I took the video. This is the only explanation for the magenta cast (supplied by a guy at Backscatter in Monterrey, California) that I have contemplated that makes any sense to me. That was the first time I had used that camera and I was a raw beginner (not much better now).

This dive trip to the Sea of Cortez did not occur in such strong currents as the Cozumel trip, and I was able to concentrate on the photography a bit more than when chasing the dive master and my girlfriend in a drift dive. In addition, I got bifocals for my dive mask prescription, and this has allowed me to see the controls on the camera much better -- and the monitor screen too. It makes a huge difference!! I have learned that you really do need to monitor what you are shooting. If the thing is going wrong, you can see it in the monitor -- for example with the exposure and with the white balance too.

Here, I was NOT using a picture profile. I was using a "Magic Filter" (like I did in Cozumel) but was using the camera's underwater auto white balance. It works sometimes and sometimes not, depending on the location of the sun, and the quality of the light. And as I mentioned to TaxiDiver, there are two versions of each file -- one RAW and one corrected -- so you can see the extent to which you can correct files that are not shot in a picture profile.

My take away is that when shooting wide angle in ambient light far underwater, you try your hardest to get decent colors into your RAW footage, even if not done with complete technical accuracy like one would do in a controlled environment in a studio. It seems like Canon and Sony have radically different approaches to color balance. I don't know what kind of program or algorithm Sony uses for its underwater auto white balance, but they are doing something interesting. It even seems to compose colors on the fly. But it is finicky and unpredictable.

Then, as long as the RAW footage is close enough to your version of reality, that you want to convey in your film, you do the color correction. The RAW footage only needs to be close enough to give you your results. But this must all be done in a spirit of abstraction, and an attitude that reality, and color, is somewhat subjective in any event. That appears to be the Sony approach. I have not yet tried the Canon cameras but from what I have read and heard, they take a much more quantitative approach, and are able to handle far greater color temperatures.

Ammar:

I would be extremely interested in your sLog 2 experiments. May I suggest that you do some experiments shooting the same scene with and without the picture profile? Then we can test whether there is any real benefit to shooting in a log profile The jury is still out for me. And there are disadvantages. I don't think you can take a custom white balance in the sLog 2 picture profile, so you need to take one (if you are doing it that way) and then switch profiles. And, you will need to switch to take photographs as well. These experiments regarding picture profiles are really on the cutting edge in my opinion, but everything seems to start with white balance. It is the sine qua non.

I don't know where I got that magenta cast but it was so strong I could not get it out even in post (not real experienced there I admit).

Many thanks for continuing to follow this thread.

Ok I got it. On second clip when you correct you push up magenta too much on whites. You can see it on ths sun ball.

Yes I agree. I was not really trying to do a final version, just sort of roughing it out to show what you can do. Many strange things happen when you start fiddling with the colors and levels.

On a different note, I am very impressed by your Down's syndrome work. That is awesome and a great way to utilize your diving and photography skills. I love your editing and use of music as well!

Thanks Ammar:

 

On the first video with the magenta cast, I was trying my best to do a custom white balance, at 60 or 70 feet, and now I know that you really can't do that with this camera. In addition, I think I did the balance and then ascended a little, so whatever I did, was done at 15 to 20 feet deeper than where I took the video. This is the only explanation for the magenta cast (supplied by a guy at Backscatter in Monterrey, California) that I have contemplated that makes any sense to me. That was the first time I had used that camera and I was a raw beginner (not much better now).

 

This dive trip to the Sea of Cortez did not occur in such strong currents as the Cozumel trip, and I was able to concentrate on the photography a bit more than when chasing the dive master and my girlfriend in a drift dive. In addition, I got bifocals for my dive mask prescription, and this has allowed me to see the controls on the camera much better -- and the monitor screen too. It makes a huge difference!! I have learned that you really do need to monitor what you are shooting. If the thing is going wrong, you can see it in the monitor -- for example with the exposure and with the white balance too.

 

Here, I was NOT using a picture profile. I was using a "Magic Filter" (like I did in Cozumel) but was using the camera's underwater auto white balance. It works sometimes and sometimes not, depending on the location of the sun, and the quality of the light. And as I mentioned to TaxiDiver, there are two versions of each file -- one RAW and one corrected -- so you can see the extent to which you can correct files that are not shot in a picture profile.

 

My take away is that when shooting wide angle in ambient light far underwater, you try your hardest to get decent colors into your RAW footage, even if not done with complete technical accuracy like one would do in a controlled environment in a studio. It seems like Canon and Sony have radically different approaches to color balance. I don't know what kind of program or algorithm Sony uses for its underwater auto white balance, but they are doing something interesting. It even seems to compose colors on the fly. But it is finicky and unpredictable.

 

Then, as long as the RAW footage is close enough to your version of reality, that you want to convey in your film, you do the color correction. The RAW footage only needs to be close enough to give you your results. But this must all be done in a spirit of abstraction, and an attitude that reality, and color, is somewhat subjective in any event. That appears to be the Sony approach. I have not yet tried the Canon cameras but from what I have read and heard, they take a much more quantitative approach, and are able to handle far greater color temperatures.

 

Ammar:

 

I would be extremely interested in your sLog 2 experiments. May I suggest that you do some experiments shooting the same scene with and without the picture profile? Then we can test whether there is any real benefit to shooting in a log profile The jury is still out for me. And there are disadvantages. I don't think you can take a custom white balance in the sLog 2 picture profile, so you need to take one (if you are doing it that way) and then switch profiles. And, you will need to switch to take photographs as well. These experiments regarding picture profiles are really on the cutting edge in my opinion, but everything seems to start with white balance. It is the sine qua non.

 

I don't know where I got that magenta cast but it was so strong I could not get it out even in post (not real experienced there I admit).

 

Many thanks for continuing to follow this thread.

And in addition, when shooting in sLog picture profile, it is much harder to monitor, because of the flatness of the monitor as it has yet to be "delogged" YOu must use that Gamma display assist and I wonder how accurate that is as far as monitoring the footage. That too will be an interesting experiment.

Thank you George for the info. I find custom WB underwater a pain in the neck. Tried it once when I bought my Canon 5DM II rig back in 2008 and never again.

Yes sure, this is a great idea, will shoot as you suggested with both S-log2 and without.

A little of morning WORK...

A little of morning WORK...

 

Very nice. What program is that? You look like you are working with a vectorscope.

Thank you George for the info. I find custom WB underwater a pain in the neck. Tried it once when I bought my Canon 5DM II rig back in 2008 and never again.

 

Yes sure, this is a great idea, will shoot as you suggested with both S-log2 and without.

Ammar: I am going diving in the Caribbean in two weeks, and I will try that experiment as well. I hope to get really excellent results there with the ambient light, given the clarity. I will try some comparisons of the picture profiles. Any reason you are shooting in S-Log2 rather then S-Log3?

GeoPaul7.... no vectorscope no honey hahahaha....

Program is Edius Pro 7.53