Green screen windows on sound stages.

[Roberto Lequeux]

I take that having a 4k slate would help thanks to its size... especially for a small window in the shot. Also that for the few times when looking out the window is an actual action and part of the plot then I would probably shoot at the real place... shooting the window means you should have plenty of space behind you in the actual room to position the camera and crew. Shooting looking into the cabin through the window would be easier yet.

But if we are going to need to move walls to shoot a few important scenes that happen inside the room, so we can have freedom, then I am wondering about how we'd match the motion... I mean matching the exterior shot to the motion of the camera on the shot from the soundstage.

How? With what software? Easy? Hard?

I may have phrased this question all wrong... but I hope the essence of my question is clear. How do you make it work if you are moving the camera in the stage. I guess you track two or three points in the room? But is it really that simple? Would After Effects not be a poor choice?

 

[Richard Andrewski]

Of course if you use green screen composite for the window, then if the camera moves you'll have to track the composite shot too, so it moves realistically with the camera angle. Having a locked off camera would help with that problem.

I think that's why many just use a painting or blown up photograph of a real location outside the window in a set. Then they don't have to worry about it.

 

[Roberto Lequeux]

Of course if you use green screen composite for the window, then if the camera moves you'll have to track the composite shot too, so it moves realistically with the camera angle. Having a locked off camera would help with that problem.

I think that's why many just use a painting or blown up photograph of a real location outside the window in a set. Then they don't have to worry about it.

Hi Richard, thanks for the reminder... Yea... I guess it can't be that expensive and I really haven't delved into VFX, nod do I intend to. That could prove to be too much of a problem.
But I wonder how much $$$ it would be? And were I could have that done, hopefully in MN.

 

[Richard Andrewski]

Hey Roberto,

I think many are using Shake or Digital Fusion these days. Some like After Effects. Many would probably say that lighting the screen with 5000K to 6000K would be best for the RED Camera and less noise. Personally, I'd go the low tech route for a window and even dress the outside with a couple of fake plants or small trees to give it some depth. Then you're free to do all the camera movements / zooms you want when someone is near or looking out the window.

 

[Roberto Lequeux]

But how much? The outside is a character in my script, so it can't be ok. It needs to be great. I figure it cant be cheap. I am not sure. Stills are stills.

 

[Shawn Booth]

Sounds like you want a motion control rig.

After Effects is more widely used than Shake and is great to use.

When you incorporate GS/visual effects (they're not special - special fx are physical effects done on set, explosions, bullet hits, breaking glass, etc) here's a quick break down of work:

Once you have motion control -
Pull Key (hopefully you have lit correctly and have no spill)
Rough shots together
Track shots together
Composite
- many steps involved in the blending of two shots

I take that having a 4k slate would help thanks to its size... especially for a small window in the shot. Also that for the few times when looking out the window is an actual action and part of the plot then I would probably shoot at the real place... shooting the window means you should have plenty of space behind you in the actual room to position the camera and crew. Shooting looking into the cabin through the window would be easier yet.

But if we are going to need to move walls to shoot a few important scenes that happen inside the room, so we can have freedom, then I am wondering about how we'd match the motion... I mean matching the exterior shot to the motion of the camera on the shot from the soundstage.

How? With what software? Easy? Hard?

I may have phrased this question all wrong... but I hope the essence of my question is clear. How do you make it work if you are moving the camera in the stage. I guess you track two or three points in the room? But is it really that simple? Would After Effects not be a poor choice?

 

[Jeff Kilgroe]

This can be handled without motion control. If you plan to build what's outside the window in CG, then...

Set your green screen behind the window. Set tracking points on the sound stage, primarily room and window corners. Make sure you have enough tracking points to keep a minimum of 3 points in frame in any given shot.

In post for the CG portion, you construct a stand-in model of the same dimensions as your room. It's easy if you also mark points on your model to match exact locations of the tracking points you have set on set. Build your virtual set / character(s) around your stand-in room and window. Good tracking software can also build a stand-in model with identical reference points to track your footage / camera motion. This can be exported into the 3D application along with all your lens/shot specs for rendering out your CG for compositing

From there, you have what you need to start compositing. You will most likely have to do a lot of tweaking by hand to make it all look just right. Aside from the CG artistry, it's all pretty simple in concept. but can be very tedious and frustrating in terms of actual execution, learning software or dealing with various software quirks framing and perspective issues depending on how you shoot, what lenses, etc.. In other words, it takes time and money.

The other way to go is build your exterior set on the sound stage, beyond the window. Or build your set in the middle of the environment you're trying to capture outside the window. You shoot your scene and what you need to capture is already there. Practical effects work if handled properly.

 

[Charles Angus]

Depending on the distance of the exterior and what it is, you might need motion control. In that case, you're looking at big bucks. A moco dolly with a jib and operator is going to be at least $$$$ a day, haven't looked at it recently.

If the background has little parallax, ie. is almost a flat plane, you might be able to get away with doing a similar camera move (matched as close as possible), and tracking and comping it in a 3d aware compositor to get parallax between the window and background. Time with a compositor is also not cheap.