106 replies to this topic

[Nick Hope]

The green channel on that last shot is actually clipped, meaning you can't retrieve detail from the highlights. You want to be doing something during image capture to stop that happening. Sony Vegas Pro scopes:



I would start with putting curves something like this on it:



Which gives this:



Not right but at least you can see more detail in the highlights in the sand.

[SimonSpear]

I certainly agree that colour correction is subjective to some degree, but I've never really understood trying to match what your eyes see underwater. After all it is only your brain's perception of colour that is letting you see anything but blue below a few meters.

Regardless of what ultimate effect we go for it certainly helps to get as close to that as possible while filming. Perhaps as RAW (and/or higher bitrates) becomes more mainstream we won't need to worry so much, but I've seen lots of issues even with RAW footage underwater. 4:4:4 and 4:4:2 are certainly a big advantage over 4:2:0, but they don't solve all the problems. The cameras we use are full of very cleaver electronics but they are really not designed to film in these kinds of environments, so we need to trick them into getting what we want. Some cameras are easier to trick than others and it could be that the FS100 is one of the harder ones....

Nick I've generally found that you need exposure to be pretty close to retain detail in highlights. Parts of the sand in the original image were blown out and with the green colour cast that is possibly why the green channel is clipped? You are a lot better at the 'Science bit' than I am so I'll defer to you on that!

Cheers, Simon

[SimonSpear]

Just had 5 mins to play around with the image. This is probably near to what I would have ended up with. It doesn't look like it was possible to regain all the detail from the highlights, but to be honest closer than I thought it would be...



Mike what PP were you using? If I'm not shooting a flat profile I generally use PP5 for topside so definitely interested to hear what this was. It looks like with a bit more tweaking we could be gettings some nice results straight out of camera.

Cheers, Simon

Edited by SimonSpear, 04 December 2012 - 02:09 AM.

[Nick Hope]

That's much nicer than my brief effort Simon. I should have desaturated more.

[thani]

Hi guys, Thanks for starting this important thread. The white balance issue is a very challenging one with both the FS100 and the FS700, I believe.
Take a look at these videos taking by Sultan using the custom hosing built for the FS700 http://wetpixel.com/...showtopic=47975. Although the video is shaking, there was no way to avoid this due to pressing a hard manual button repeatedly. Forgive us for that .

I am posting two different videos at different depths. We are cycling through the possible WB range of the FS700 which is similar to FS100. In addition, I am posting a video taking by my Sony EX1 on the same dive. None of the videos has undergone color correction. None of the cameras had red filter on - I am not a fan of that and I believe if the camera handles manual WB correctly, red filter is not needed.

The fs700 videos is recorded directly on the Ninja 2.

FS700 White Balance in shallow water (25-30):

FS700 White Balance in deeper water (40-50 ft):




EX1 White Balance in deeper water (40-50 ft) on the same dive:

I think both FS cameras use the same WB algorithm and thus both have the same challenge. I hope this adds value to the discussion.
Actually, I was planning to house an FS100 using Amphibico Genesis but honestly I am quite disappointed in the way it handles WB and I am quite hesitance to go ahead with the plan.

Regards,
Thani

[SimonSpear]

Hi Thani

Thanks for posting this and it sure looks like it is turning into a challenging issue! Unfortunately until now that is almost exactly the water colour I've been diving in and I'm not going to see blue water until mid/end Jan to test it out myself.

What lens did you have on the FS700? Do you remember your settings (gain/iso, aperture?).

It looks like at 15000K there still was not enough red being captured without a red filter on the lens. Out of interest why so anti filters? Sure I would always rather not use one, but if I'm not getting the results that I need without one then it kind of becomes a moot point. Yes you'll loose a stop or two, but with the FS100 low light performance that shouldn't really be an issue.

Did you try one touch WB at all? That 'should' be able to break through the 15000K barrier...

Hmmmmmm

Cheers, Simon

[thani]

What lens did you have on the FS700? Do you remember your settings (gain/iso, aperture?).
Did you try one touch WB at all? That 'should' be able to break through the 15000K barrier...

Hi Simon,

The lens used was Carl Zeiss 24/1.8. Sultan loves it.
Aperture/iris was Auto, Gain was locked at 0, Shutter was locked at 60 and the frame rate was 30P.
BTW, even when we had all setting of the above on Auto and did the WB temp setting, we were getting similar result.

We are still to make a whole in the custom housing for Manual WB.

I love how EX1 handles WB and paints the sea bed beautifully. I hope the NEX-FS can match.
re. Red filter, I really respect your expert view but is it really needed when WB is done correctly?

Regards,
Thani

[r4e]

A red filter seems to make a big difference, atleast at relatively shallow depths as can be seen here:

[vimeohd]48561076[/vimeohd]

This video was recorded by Kraakhelder Productions. The following details are quoted from the vimeo page:

"The underwater footage is shot by the FS100 [which] I took with me in a second hand Sony MPK F-40 housing. Together with the Sigma 10-20mm it was almost fitted perfectly."

"Because of the underwater housing I used that isn't made for the FS100 it was impossible to control any of the buttons on the housing, except the recording handle.
After some test with the camera on full auto I set my white balance on 5600K and screwed a red filter on the housing. Next to that I just used the automatic shutter and gained my shots with 6db since I used that Sigma 10-20 F/4-5,6. The camera knows how to deal with low light situations, but I had to make sure my shutter wont go under 50..
I found out that this was the best way for me to use the FS100 underwater."

"I love the FS100, especially underwater!
The PP I used is one of James Millers profiles.
BLK LEV: -15 to +5 depending on shot. 85% using -15
GAMMA: CINEMATONE2
BLK GAMMA: RANGE HIGH / LEV +7
KNEE: 75% / +3
COLOR MODE: CINEMATONE2 / LEV 8
COL LEV: 0
COL PHA: -2
COL DEPTH: R+5 G+1 B-4 C-4 M0 Y+4
WB SHIFT: FILTER R-B / LB 0 / CC 0 / RGAIN -2 BGAIN -1
DETAIL -7 / V/H BAL +2 / TYPE 5 / LIMIT 7 / CHRISP 7 / HI-LIGHT 0
The clips have been graded in FCP 7 using the standard 3-way colour corrector"

Edited by r4e, 22 December 2012 - 11:34 AM.

[r4e]

Oops, sorry. I just noticed that the OP was about WB at depth. I am personally interested to hear about experiences for the 30-60m range if and when there is still some ambient light. Of course, I do not expect to see much red without a fill-in lamp;-)

[mmccue]

I'm glad to hear you love FS100 too, and thanks for sharing your experiences and film r4e. It seems like with the right picture profile, red filter, and custom color temperature dialed in, the FS100 can definitely work well underwater. I just haven't found the perfect blend yet, but I'm getting close. I am now convinced that I need to use a less saturated profile, so I've entered a couple new ones to try on my next dive. I'll also give your pp a try. I guess it must be a bit darker where your shooting, or your filter must block more light than mine. What depths were the scenes in your film shot? Using the sony 16mm f f2.8, I've been as deep as 25 meters now with a filter, and I've never had to set my shutter speed below 60, or raise the gain above zero to get a good exposure. Also, I've been shooting 60p exclusiviely.

I mentioned the issue that I've had with the manual one push white balance earlier. I'm still curious to hear if anyone else has experienced the same thing, but it sounds like the housings that your using don't allow access. I can only manually white balance with one push and a card to a depth of maybe 10 meters. After that, the camera just seems to choose random (and really wrong) color temps, so that's when I'm now switching to preset, and dialing in the temp myself. With other sony cameras I've used, if the camera can't find a proper setting, the icon just continues to flash and it keeps the previous setting. Any ideas why this is happening with the FS100, and do you think there's a way around it? My best results in the past have always been with manual white balance, but maybe I just have to accept that my old methods won't work with this camera.

I finally purchased a Ninja 2 deck, so I'm looking froward to trying that out. It doesn't look like the Amphibico housing for it is available yet. Hopefully they haven't given up on it.

Mike

[r4e]

thanks for sharing your experiences and film r4e

Just for clarification, I am not associated with Kraakhelder Productions. All honor belongs to them.
You should be able to contact Kraakhelder via vimeo for further information about their setup.

I provided the vimeo link and quotes merely in an attempt to help other Wetpixelers to try and find the right settings and/or make their mind about purchasing a FS100 housing. I belong to the latter group. FS100 with a housing would seem to be a very interesting sweetspot combination of video and image quality, still reasonable size for travel and cost. That is, IF the WB can be solved.

On most of my dives, the illumination of a single dive ranges from pitch black (caves and Baltic wrecks) to midwater green or sometimes blue. Thus a (flippable) red filter would only be a partial solution. Of course one solution is to bring a lot of light with you. Currently, I have 28000 lumens of light plus a short shopping list of some more. But, then you need a small team to hold the off-camera lights.

Mike, have you been able to get nice blue water graded backgrounds with your FS100? Any banding or encoding artefacts?

[thani]

Guys, I really like the fs100 and this thread is not intended to debate whether this camera is good or not , its focus is to discuss the challenge of manually White Balancing the camera underwater.

Thank you r4e for sharing the video and I tried using the same PP long in the past with no luck in improving WB.

The video produced by Kraakhelder Productions is really lovely especially topside and it is a mix of both DSLR and FS100 (for underwater). But bear in mind we are trying to post videos/shots without color grading as shot by the camera.

Kraakhelder Productions says:
"The PP I used is one of James Millers profiles and graded in FCP 7 using the standard 3-way colour corrector"

regards,
Thani

[r4e]

I agree with the target of achieving WB without needing to use any post-processing.

Please correct me if I am wrong, but, I would have expected more response in the image when stepping through the color temperatures - thanks Thani for sharing that. Could it be that the WB adjustment is diminished to some degree due to some other "stronger" control or compensating autoadjustment that limits the range available to WB adjustment? Disabling that control might allow for a larger WB adjustment range.

Hopefully the WB adjustment is done in the analog compontents (amplication) before the A/D converters in the camera. Otherwise, if the WB is done internally in the digital stages, there is far less latitude for WB adjustment without introducing other artefacts like banding. This is why I am interested to know how well the camera reproduces a graded blue or green water background (without any creative work in CG).

Just my 2 cents.

[RWBrooks]

Seems like you might have hit upon something there r4e.
Surely the camera is being conflicted here by something else that users haven't found yet.

Richard

[thani]

I would have expected more response in the image when stepping through the color temperatures - thanks Thani for sharing that. Could it be that the WB adjustment is diminished to some degree due to some other "stronger" control or compensating autoadjustment that limits the range available to WB adjustment? Disabling that control might allow for a larger WB adjustment range.

I expect moving from 2k to 15k to cause the image to go from more blue to more red and vise versa. When the same is done on land, the camera reacts correctly. Strangely,underwater the camera misbehaves due to some reason.

Aperture/iris was Auto, Gain was locked at 0, Shutter was locked at 60 and the frame rate was 30P.
BTW, even when we had all setting of the above on Auto and did the WB temp setting, we were getting similar result.

We tried tried to compare both cameras by setting the WB I am getting from EX1 manually into FS100. Technically, we were trying to use the EX1 as a meter. That rock shot by EX1 with WB set at 11k roughly and the same rock (second clip for fs100) does not change color event at 15k .

The question is why the FS100 behaves differently underwater than on land when you cycle through the WB temp range given the same settings?

Guys with fs100 can help here

[mmccue]

Sorry I can't answer your question thani, I can only add more questions to the mix for now. Your observations reminded me of something that I discovered while setting up my camera on land the other day. I always run through the functions of the housing at the home just to make sure everything is working correctly. While doing that (with my red filter on), I noticed a big difference in the look between the manual white balance and the preset white balance with the same color temp dialed in. I just recreated those results in my car port using a white slate and some colored bins, with and without the red filter. I'll attach some screen captures of results below now.

As you'll notice, the two white balance methods produced what look to be identical results without the filter on the lens, but radically different results with the filter on. So the camera is clearly doing something differently with the manual one touch method, where it can manage to compensate for the extreme color change caused by the filter. With the preset, the camera does NOT do the same thing, and isn't able to compensate for the filter. I imagine it's the same at the surface (or shallow water), and then at depth. With a manual white balance it can compensate for the color change caused by the water, but it does not compensate the same when the temperature is preset. That explains why I am able to get good results by manually white balancing in shallow water, but like I mentioned, the manual white balance just won't work at depth, so preset is the only choice I have.

So the question seems to be, what is the camera doing differently between the two methods, and is there a way to get it to do the right thing at depth?

[SimonSpear]

Hi Mike

Have you tried using different filters when using one touch WB? The V1 which was the last Sony camera that I used underwater before the FS100 had exactly this issue. For example when using a Magic Filter I was normally only able to WB to 10-12 meters, but with a URPRO filter I could get easily get to 20-25m and sometimes deeper.... I know I've stated this before but I've found URPRO filters to be head and shoulders above any other red filter that I've used.

I also remember when the Z1 was having some of these issues (very green water when using one touch WB) some were advocating the use of an Expodisc on a flip filter, although I'm not certain how that could be used on FS100.

It is only 3 weeks or so now till I'll be able to get below 10m in some blue water and start experimenting myself!

Cheers, Simon

Edited by SimonSpear, 24 December 2012 - 03:03 AM.

[SimonSpear]

re. Red filter, I really respect your expert view but is it really needed when WB is done correctly?

Regards,
Thani

Don't know about 'expert' view Thani (!!), but yes in my experience a red filter makes a huge difference. The only camera where I have found I didn't need to use a filter was a 7D, which for some reason was able to WB at any depth with remarkable results.

[r4e]

I expect moving from 2k to 15k to cause the image to go from more blue to more red and vise versa. When the same is done on land, the camera reacts correctly. Strangely,underwater the camera misbehaves due to some reason.
...
The question is why the FS100 behaves differently underwater than on land when you cycle through the WB temp range given the same settings?

Apart from differences in lighting, the only other difference would be the housing.

Thani, everybody appreciates your testing with a home modified ex-housing. I wonder how have you been able to replicate the dual action of the "SEL/PUSH EXEC" dial which you seem to be using for the manual WB setting? From your test video, it is obvious that the dialing part (SEL) works, i.e. the numbers change. But, are you sure that you also are able to depress the dial inwards enough (PUSH EXEC) so that the setting would actually take place? Please forgive me if my question is too naïve.

Perhaps you could try settíng the camera to some known or extreme setting, e.g. 11K or 15K, before enclosing the camera in the housing.

Guys with fs100 can help here

This WB issue bothers me so much, that I might have to go out and rent the camera just to find out more before actually purchasing it. If it consoles you at all, I might mention that I did work for half a year in UAE in 1979 before entering the broadcast TV and computer graphics business.

[SimonSpear]

Thani, everybody appreciates your testing with a home modified ex-housing. I wonder how have you been able to replicate the dual action of the "SEL/PUSH EXEC" dial which you seem to be using for the manual WB setting? From your test video, it is obvious that the dialing part (SEL) works, i.e. the numbers change. But, are you sure that you also are able to depress the dial inwards enough (PUSH EXEC) so that the setting would actually take place? Please forgive me if my question is too naïve.

Perhaps you could try settíng the camera to some known or extreme setting, e.g. 11K or 15K, before enclosing the camera in the housing.


This WB issue bothers me so much, that I might have to go out and rent the camera just to find out more before actually purchasing it. If it consoles you at all, I might mention that I did work for half a year in UAE in 1979 before entering the broadcast TV and computer graphics business.

The WB performs flawlessly on land (I've had the FS100 for over a year topside now), it is just UW where there are apparent issues, although I've not been deep enough since I've had a housing to see this. Another option could be that as the K increases the image just keeps on getting greener and greener becuase there is no red in the image without a filter. The fact that green is there rather than blue means it will be easier to fix in post, but not a solution I'm happy with. Perhaps I'm clutching at straws here, but extremely frustrating until I can test this out myself.

Cheers, Simon