Solving the Mixed Light Problem

Some real world feedback from last week in the Red Sea -- 

I tested out both the

• Lee 353 + Rosco 4330 = 23000k + 121 Magenta, about 1 stop light lost
• Lee 1/2 CTB + Rosco 4330 + Rosco 4390 = 16000K +150M, about 1 and 2/3 stop lost

At 5 meters with DivePro G18 lights. They blended it seamlessly with an ambient white balance at this depth, filling in the shadows:

Just ambient light:

+ 2x DivePro G18 lights w/ Lee 1/2 CTB + Rosco 4330 + Rosco 4390

+ 2x DivePro G18 lights w/ Lee 353 + Rosco 4330

+ 4k DivePro G18 lights (2 with first filter combination, 2 with second filter combination)

So as you can see both the filter options worked well, and they worked well together too. None produced weird results. However, given the stength of the ambient light, there's a noticable difference in ability to fill in shadows (look at the mask) when using 4x 18k lumen lights vs. just 2x.

From this point on, I used the Lee 353 + Rosco 4330 combination on all 4 of my lights as I thought it did a slighly better job than the more cyan Lee 1/2 CTB + Rosco 4330 + Rosco 4390 filter combination in the conditions found in the Red Sea.

I'm pleased to report that this filter combination produced great results all the way from 5m to 30m in depth. So, setting a white balance based on ambient light and filling in with the DivePro G18 lights + Lee 353 + Rosco 4330 filters on the lights produced very pleasing results in my view. Here's an example at 30 meters:

And 20 meters:

And 15 meters:

And this is how it renders skin-tones at 20 meters. Pretty good, I think!

Great job!

The blues seem a little washed out. I assume the frame caps are ungraded?

1 minute ago, adamhanlon said:

Great job!

The blues seem a little washed out. I assume the frame caps are ungraded?

Yes, the first set of frame grabs at 5m are from R5 C raw video with Canon's offical Canon Log2-12(bit) to Wide DR lut applied.

The second set at various depths is directly out of camera h.265, filmed in the EOS Standard picture profile.-

A bit of color grading of the raw files can get you very nice results indeed at 10 meters:

12 minutes ago, adamhanlon said:

Great job!

The blues seem a little washed out. I assume the frame caps are ungraded?

Agreed! 

Thanks for the update Andrei!

Also on the first pictures there is quite some noise in the blues? or it is just my idea?

Where you using a red filter on the lens or just a CWB? Would be interesting to see the results with a red camera / blue lights filter combination but also when the WB is set on the color temperature of the lights without any filters.

1 hour ago, dreifish said:

Yes, the first set of frame grabs at 5m are from R5 C raw video with Canon's offical Canon Log2-12(bit) to Wide DR lut applied.

The second set at various depths is directly out of camera h.265, filmed in the EOS Standard picture profile.-

A bit of color grading of the raw files can get you very nice results indeed at 10 meters:

Nice skin tones indeed! Too bad that usually divers are covered head to toe with black suits :)))))))

7 minutes ago, Lionfi2s said:

Agreed! 

Thanks for the update Andrei!

Also on the first pictures there is quite some noise in the blues? or it is just my idea?

The shots were somewhat underexposed. I had to bring them up ~2 stops in post and it's coming off a RAW capture with no noise reduction applied. So yes, they're noisy. Shooting RAW on the RC 5 really is a bit finicky when it comes to exposure and noise.

9 minutes ago, Lionfi2s said:

 

Where you using a red filter on the lens or just a CWB? Would be interesting to see the results with a red camera / blue lights filter combination but also when the WB is set on the color temperature of the lights without any filters.

No red filter, just CWB done in camera off the sand without lights. So, basically a CWB done for the ambient light.

If you set WB in camera for the lights without filters (i.e. 5000 Kelvin) and then put the filters on, you'll just end up with very bluish-green footage. 

In my experience in the Red Sea shooting a cyan 60 with a red filter of your choice covers all situations with two lights.

For photos I tend to use a cyan 90 as strobes are much more powerful or another blend that I do not recall what is called

I do not like the CTB or the URPRO too much they have orange cast and the blue are never deep enough

Generally for photos  I use magic and for video keldan filters

This time I have also used no filter on the lens and cyan 60 on the light or nothing on the light in some cases it resulted in too warm image that I corrected later

52 minutes ago, dreifish said:

The shots were somewhat underexposed. I had to bring them up ~2 stops in post and it's coming off a RAW capture with no noise reduction applied. So yes, they're noisy. Shooting RAW on the RC 5 really is a bit finicky when it comes to exposure and noise.

No red filter, just CWB done in camera off the sand without lights. So, basically a CWB done for the ambient light.

If you set WB in camera for the lights without filters (i.e. 5000 Kelvin) and then put the filters on, you'll just end up with very bluish-green footage. 

I meant without filters on the lights to see the difference.

10 hours ago, Lionfi2s said:

I meant without filters on the lights to see the difference.

And custom white balance off the lights? You’ll just end up with natural colors in the foreground and everything in the background blue. 
 

Conversely, if you CWB for ambient and use no filters on the lights (or filters that are too weak),  your foreground subject will turn red.

Well its subjective but in some scenes I prefer the color contrast created with just custom white balance on the lights.

I ve just started using ambient filters but my first impression is that the image comes back a bit flat (no color contrast).

2 hours ago, Lionfi2s said:

Well its subjective but in some scenes I prefer the color contrast created with just custom white balance on the lights.

I ve just started using ambient filters but my first impression is that the image comes back a bit flat (no color contrast).

Certainly, I think of them as two different styles or looks -- one is the traditional strobe photography look, with high color contrast between foreground subjects and blue background. The other is the blended video look, with more muted colors but consistency between foreground and background. (You can achieve either result in both photos or video, the technique is ultimately the same).

Which one you choose is a creative choice depending on what you think best suits the content and mood you're trying to create. Personally, I think the blended ambient light look works best when you're 12 meters or shallower and there's still enough red light to get nice colors. On deeper dives (especially below 30 meters) there isn't much point to CWB for ambient light in my view and the overall amount of ambient light is dim enough that video lights can easily overpower it. I think video lights without filters and WB set to 5000k gives aesthetically better results at this depth also.

As a side note - any tips on where to buy cyan filter sheets? I'd like to give it a try, and I'm trying to source Roscolux cyan 60 and 90 (4360 / 4390) and keep stumbling on Full Compass on ebay and amazon, who simply refuse to ship to Palau where I am now...
I've emailed Rosco but doubt I will get a response.
thanks

b

I purchased both the Lee and Rosco gels from Adorama and B&H Photo Video.. they didn't always have them in stock in standard 24x22" sheets. 

1 hour ago, dreifish said:

I purchased both the Lee and Rosco gels from Adorama and B&H Photo Video.. they didn't always have them in stock in standard 24x22" sheets. 

Adorama works, $4 shipping! Thanks a bunch

I’ve wanted to weigh in on this topic for a while and have just been a bit to busy to organize my thoughts.

First, my base line is I shoot a Sony A1 or A7s3 in a Nauticam housing. Lenses ports and domes for 16mm thru a 90mm macro. Keldan 4X lights with Kedlan red camera filters and blue filters for the lights.

I am a big believer in the grey card WB and color chip reference at depth, and redone as depth and conditions change. I typically shoot from surface to 15 meters. Much deeper and lights are required. Next dive I might shoot that fixed 500k light solution for grins and giggles.

My preferred rig when going down is ambient light video shooting with the A7s3 at 4K with somewhere between 60 and 120 fps at the high ISO that is clean for noise. (128000? I forget exactly)  Lens choice is typically 35 prime with flat port or 16-35mm with a dome. I also shoot with the S-Gamut3/S-Log 3 profile. I also shoot 1.7 f-stops over exposed.

On the mixed lighting question, again contrary to what other have posted as process I do my WB with ambient and the lights at the same time for a given dive, depth and conditions. I have made my living on the surface shooting pro video and have always done WB with the final lighting solution. So I follow that protocol underwater as well.  I now prefer to keep my UW kit as simple as possible, so that I enjoy the diving with out fiddling with gear all the time. I enjoy diving and observing as much as shooting. Now I have noticed that the 4x Keldans with the blue filter do not add a sufficient amount of light to make a difference. Probably a 8X light would be better but I suspect they would add so much weight and volume to my travel kit that that my carefully arraigned carryon and checked bag solutions would be seriously messed up. Yes, it’s that close in specs for international travel with legal carry ons and one checked bag.

I color grade in DaVinci Resolve and no longer use LUTs. Prefer to just “work it” and with the ambient light and flat profile and I have remarkable flexibility.

13 hours ago, Whipauee said:

Now I have noticed that the 4x Keldans with the blue filter do not add a sufficient amount of light to make a difference. Probably a 8X light would be better but I suspect they would add so much weight and volume to my travel kit that that my carefully arraigned carryon and checked bag solutions would be seriously messed up.

Do you mean you have 2 Keldan Luna 4x (10k lumen) light? Or 4 Keldan lights? 

If you do indeed only have 2 10k lumen lights, then yes, once you add the filters which cut about 1 2/3 stop of light, you're basically working with 3000 lumen lights. That's much too weak to make any difference for wide angle video. Given how little influence the video lights have, it doesn't matter whether you do CWB with the lights on or off.. practically, 90+% of your illumination is coming from the ambient light, not your video lights.

Switching the Luna 4x for Luna 8X will help a little bit, but you still only have 30k lumens to start with, before accounting for the light loss from the filters. And unfortunately the Keldan lights have a 110 degree beam angle, which further reduces the illuminance that actually falls on your subject.

In my experience, you need about 60k lumens of video lights (think, 4 Keldan 8x's) before you start adding the blue filters if you want the lights to actually make a difference.

I agree in general, that's why I prefer to just shoot ambient as long as the sun is not near the horizon. I guess if I do try and light things up a bit I don't bother with the blue filters. My stuff is mostly fish portraits and details, not too many wide angles unless I feel the need for an establishment shot. My cameras are pretty good at gathering light so sometimes just a bit may make a difference. Also s-log helps if you can get to slightly overexposed.  A sadness for me is the gloaming part of the day is when there is interesting fish activity. More light would help but then that can often just bother the fish/creature and they depart.

Really I vary my kit depending on conditions. I do love quickly locking in a clip/action but I also like what ever flexibility I can take down with me. But mostly simpler is better.