bluescreen articles

[Allen Nash]

Are there any well written and informative online articles about doing bluescreen work on the ultra cheap. I want to do an expiremntal film which uses a lot of bluescreen. My equipment is primarily a DVX100a and Sony Vegas 5.0 . I'm looking for techniques and what I can and can't do. Ideally I'd want to do pans, tilts, wide shots, maybe even camera movement all using blue screen but I'm not sure what is and isn't possible.

[Nick Jushchyshyn]

Here's an article on building a large screen very inexpensively.
And here's one about which color may be better to use.

I've heard good things about Vegas' compositing, but I'm not sure that it would be up to the task of a full project of bluescreen shots with camera moves.

After Effects Pro has built-in 2D tracking to help with basic moves.
For more complex camera movements you should consider
RealViz MatchMover , or
2d3's boujou bullet , or
Pixel Farm's PFTrack.

None of these are inexpensive options, though PFTrack's educational license is under $100. There was also a free program called Icarus floating on the net at one point, but that was since purchased by Pixel Farm and is now PFTrack, not available for free anymore.

Hope this helps.
Good luck.

[Allen Nash]

that helps a lot. I can afford those programs, but the problem I have isn't cost but the logistics of it all. I want to do camera moves and know what my options are in terms of what is and isn't possible, but don't know how to prep everything so that I don't have a post-production nightmare unexpectadly pop up two months down the road. I hope to learn what my limitations are (since I don't have access to skywalker ranch, unfortunately), and then learn how to efficiently do what I want without getting tangled down the line.

It's all a matter of trade-offs: I can do elaborate camera moves with many levels of video but it'll look horrible and unbelievable because i don't have the equipment or knowledge, or I can do simple static shots that look clean and realistic but aren't very exciting. Then there's everything in between, but I don't know what any of it entails.

[Nick Jushchyshyn]

Sorry, I guess I was answering to the "...on the ultra cheap" note in your post.

I've used the Icarus version of PFTrack and am currently working with Boujou and Matchmover. I think Boujou was by far the easiest one to get going. It has some really slick "wizard" style hold-your-hand workflows built in. That said, I think I prefer MatchMover myself. These will all "do the job", so selection becomes a bit like picking an NLE, you got to go with the one that fits you're personal needs and no one else can tell you which is "best".

Rule #1: Be sure to have several, clear, distinct tracking points on your live set, spread out in 3D space, visible in the shot at all times. "Plus" or "X" marks on your screen and floor, and a few hanging in mid air would be ideal. These can be behind your action or off to the sides, but they need to be visible.
Having good measurements between the markers is also a great help in the post production process.

One thing you can do to make your post production life as easy as possible (which is a very relative phrase given the undertaking you are taking on) is to avoid changing your focal length during a shot. If you DON'T change your zoom mid shot, all these programs can track virtually ANY 3d camera move very easily. (so long as there are pleanty of tracking points). Zooms are possible to track as well, but they add complexity and time to the calculations. If you don't really really NEED to have the zoom action, leave it out and life will be much easier.

After that, it all becomes a matter of the skill and talent you have in your compositing, matte painting and CGI teams.

Hope this helps.
Good luck.

[Allen Nash]

thanks Nick, this is all very helpful and a good start for me. I didn't know I'd do bluescreen by placing markers on my set. How would they be visible for close-ups and tighter shots? And by 3D, do you mean I could do handheld moves or dollying and that the footage would match up with background plate? I don't see how that works, since I'd be capturing background footage seperately and don't see how it would sync up with foreground footage in post (?) maybe i should pick up a book on this

[Nick Jushchyshyn]

For close-ups, you're probably better to shoot without moving the camera. Then you can setup a 3D composited scene and add subtle camera motions (if you like) in that environment.

When you say you will be "shooting" the bagrounds seperately, will be you using a camera to record an actual location? ..or creating locations with CGI or matte paintings?

Generally, you would either create an environment that is stationary in 3D space, then animate the CAMERA in the 3D space using the data calulated by one of the programs listed in my first reply. Since this camera moves EXACTLY the same way as your live camera did, the background tracks the camera motion.

Here's a simple example I shot in my kitchen with a GL2:
Simple Camera Track (1meg, MOV)

In the Matrix, "there is no spoon."
In my kitchen, there is no gold teapot.
This is a stationary object in CG space, but since the camera was animated with data calculated from the walking camera shot using Icarus, the teapot moves in the frame in sync with the real-life counter top. You would basically do the same thing, just replacing the bluescreen with a new environment.

If you plan on shooting a real background, you're probably best to shoot a hi-res photo, then map that into 3D space using camera mapping or even photogrametery (creating a 3D object from multiple still images) for the 3D camera to have freedom of movement. (For some much better examples of how all this can work, go to Dylan Cole's website and check out his demo reel.)

Have fun.

[Yi Fong Yu]

whoa... that's pretty kewl =). excellent ideas... i've been looking to do this in the future as well.