Green screen Uderwater

[Patrick Lavaud]

I have a TVC to shoot for a clothing company and we gonna shoot some models with the Epic at 300 fps underwater with a green screen.
I’m not really familiar with underwater lighting and will love to hear from your experiences on this.
It will be challenging as, shooting 300 fps I will need a lot of lights.

Here are some details:
The green screen will be place underwater, approximately 5 meters behind the models from the surface to -4 meters underwater.
The model head will be approximately at -1 meter.
The camera will be place at -0.8 meter slightly tilting down to avoid the surface reflection.
I plan to shoot with superspeed lens.

So what will you guys recommend to light this, from the surface with HMI ? With Underwater lights ? A good mix of both ? what are you recommendation in non flickering underwater lights ?

Here is a video reference of what style we want to achieve:

Look forward hearing your experiences !

 

[Dominik Muench]

There are underwater kinoflo/ fluro fixtures that are fully submersible and can be used inside the tank. that could allow you to lite a green screen as you would on land given that the tank space will allow for it.

are you sure you want to go with 300fps and 2K though ? The footage will be quite noisy and the UW aspect makes it even more challenging/

 

[Patrick Lavaud]

I must make some test first at 300 fps UW but ya, I probably better shoot at max 240 fps max to be at least at full 2K.

Do you think fluo will be enough to light 4x4 meters green screen ? if my calculation are good, I gonna loose 6 stops shooting 240fps, and don't know yet how much stop I will loose from the water light retention.

 

[Dominik Muench]

there is an UW function in the Ccam application/ depth of field calculator if i remember correctly. you would definitely need several fixtures bu i think lighting the greenscreen from within the pool has the advantage that you wouldn't get any ripples or reflections like when you're lighting through the surface into the tank.

 

[Patrick Lavaud]

good idea, I will check the aps.

yes ripples can be an issue on the model as we don't want it looks like underwater shot, but for the green screen it shouldn't be a big issue.
I won't have reflection if I don't shoot the surface, but maybe are you pointing another problem ?

So, what if I light the green screen with HMI through the surface and light the model with UW fluos ? Does it sound right ?

 

[Dominik Muench]

possible ripples on the greenscreen is what I meant yeah, not sure how easily they would key out later on.


I probably would have tried the other way around but im not sure how you're restricted in the tank with your setups.

 

[Jason Comparetto]

Wow this is a very interesting project. Let me kick it up a notch. What if you were able to find a tank that has a clear wall? Sometimes upscale restaurants have this or aquariums. This way, you can set up your green screen from outside the tank, and just backlight it using whatever lights you have laying around. I'm sure its expensive to rent an aquarium, but underwater lights sound pretty expensive too. Plus at 300fps, multiply whatever lights you might need times 12! possibly HMI's with generators or tie-ins.

let us know what you come up with. i'm very interested to find out how this turns out

 

[Jason Comparetto]

I'm also a little curious about what you'd like the final product to look like? 300 fps underwater... won't that pretty much just look like a still image ? ... humans don't move very fast underwater. if you just want the clothes to move super slow and weightless, there may be a way to do this with air and a compressor (no water involved). I could see Leonardo da Vinci walking onto the set and saying "Think of air as just another fluid"

 

[Eric Haase]

friends dont let friends shoot 2k. its going to be really mushy, especially underwater.

 

[Pawel Achtel]

... its going to be really mushy, especially underwater.

Possibly.

Using flat or dome ports will compromise the resolution, and in the case of the flat port, probably by an order of a magnitude (as in not reaching even standard definition quality).

The options that you have are somewhat limited:

1. Shoot with a fisheye lens and a dome port (the only combination where sharpness is not adversely affected underwater).

2. Shoot with 2/3" sensor or in 2k crop mode, largest dome port you can get and a wide rectilinear lens perfectly matched and aligned with the dome.

3. Shoot with our DeepX - the only housing allowing use of submersible Nikonos lenses - the only wide angle underwater optics able to resolve 5k underwater.

I encourage you to test yourself or....

Samples of full 5k underwater images are available for pixel-peeping on our web site. We can provide 5k frame grabs of charts and MTF graphs taken with flat port, dome ports (using Master Primes) and Nikonos lenses shot in controlled environment.

hope it helps

 

[Pawel Achtel]

In terms of lighting: you can compare this out take from a giant screen commercial which was shot in 5k at 120 fps using about 12kW HMI, so if you want similar effect at 300 fps you may need to tripple your power requirements.

https://vimeo.com/48845333

 

[Patrick Lavaud]

I'm checking tank and diving pool right now, the major concern is the quality (transparency) of the water !

I think you guys are right, no need so high frame underwater, I better shoot less frame rate and have 3K.

Pawel, we not gonna shoot 5k but more probably at 3k with a 50 or 85 mm superspeed lens. Wish I can test your DeepX here in Jakarta !

you are right Jason, for the garment ECU, we will do it in studio at 240 fps, I won't contradict Leonardo da Vinci !

we will have a day of rehearsal underwater so we will test all that !

another update on the shot itself, on the final delivery, the background will be full black but I think I will still shoot it with green screen as all the talents are Asian with black air and even with good back light I'm afraid it's gonna be a pain to obtain a nice and constant deep black background. should be easier to key the green screen. any thoughts ?

Here a video deference with underwater shot with black background, obviously they shot with "black" background, the black is not constant. also we don't want any surface reflection like they did.

 

[Patrick Lavaud]

Great shot Pawel !

Are you saying that only wide angle lens can keep the sharpness with a "classic" underwater casing ?
If I don't misunderstand you, it's better to shoot with a fish-eye cropped at 2K than a 50mm at 5K. Can you please explain me.

 

[Patrick Lavaud]

Hi guys,

finally done with the shot !

We end up to shoot in a dive center behind a glass as no Epic underwater casing was available in Indonesia.

we shot up to 240 fps at 2K.

no single underwater lighting was available either so everything had to be lighted from the surface. I used only tungstens lights, mostly 24 Kw, 10Kw and Pars (CP61)
Total power used was around 110 Kw...
To avoid surface reflection on the green screen and the talent I installed two large butterfly at 25cm under the surface. (filter 250 for the green screen and 251 for the talent)

It works good actually, the light was okay but a bit too soft and not as sharp I was hopping especially at 2K, but that was the compromise to be sure I will not have any reflection from the water surface...

We start the Editing tomorrow, will post the result when it's done.

 

[Kwan Khan]

Nice

 

[Patrick Lavaud]

and here is the result:
http://www.youtube.com/watch?v=hkYj5tqEMBI

I'm quite upset with the background, it looks like a Mac screen saver... Not what we plan at all from the beginning but well, client choice...