camera movement in greenscreen.

ben jones · January 22, 2006

Hello every one. I havn't been on the forums for a while as I have only just come off a 5 month job as a camera trainee. It was my first job since graduating from the surrey institute (where I studied cinematography). I had a great time, but found the whole thing exhausting - I guess this is normal when your tring to start out!

Anyway, Im going to be dp'ing a short film in march (probably on mini dv - either a dvx100 or xl2 with pl mount and primes) which involves two men in a boat (one being death) heading towards a tunnel at night. I havnt discussed the exact lighting requirements with the director as yet, but I do know that he wants to shoot the whole thing using green screen. I have spent all day reading all the related posts on the forums, and I must say that I have learnt so much from you all! this really is a fantastic place. What does concern me though is working knowing that the commpositer is very inexperienced with this being an almost no budget production.

keeping the camera locked off when shooting, I guess, would make things alot easier for the digital artists and compossiters as they dont have to work so hard with creating background movement to match that of the cameras. However, if the story so requires a fluid style of camera, then how do I make that compromise? Is there anyway of making the compositers job easier if I am required to use movement? I know im pretty inexperienced my self, but I do understand the importance of communication between all areas of a production. Ive noticed people mentioning shooting empty "plates" for the compositers etc. Im afraid I dont understand this, so some explanation would be wonderfull.

Aso, there is the possibility of shooting on HDV. does anyone know how easy it is working with HDV from a compositers possition? I read that people experience problems because its mpeg2. is this true? ;)

Thankyou all for your time in reading this, Ben Jones (winchester - UK)

stephen lamb · January 23, 2006

Ben,

Sounds like a tough little shoot! I am student filmmaker myself and have only dabble in greenscreen/CGi/compositing. However, i can say a few things. Move the camera as much as you want, crane it, dolly it, handhold it whatever. If the story calls for it (and i love a big moving camera myself) then by all means let it rip. I shot a short film this past fall with two distinct scenes. One was liveaction and i composited in a CGI creature. the other was all against bluescreen, with just an actress for our live action. Both scenes turned out great, and there were/are (still working on parts) two of us to do ALL of the post. Everything you read says "use 3D matchmoving software to create a virtual camera for CG" while this in theory is nice...i had absolutely NO luck with it. so i used the next best tools i could, my eyeballs. For all of my CG stuff i just brought in the shot, made a camera in my 3D package, and mathced it by eye. Then i used after effects to hone it to perfection. a little bit of photoshop, and little bit more after effects, and any 2D work was done as well. I shot the whole film handheld so it was super shaky. Basically what it comes down to is this, you shoot it however, but make sure to keep a dialogue running with your compositor(s). They should be able to make just about anything work, and don't let them say they need a bigger budget. They may have to do lots of keyframing (and i mean LOTS....hundreds, thousands of key frames) but given enough time, and some creative-outside- of-the-box thinking, literally anythign is possible. As far as shooting the greenscreen itself, keep the talen far enough away from the screen as possible, and light them however you need to for the scene. Light the screen as even as possible, and my personal prefence is to light it about a stop darker than the foreground, though some will say light it a stop brighter. I hope this helps, i'm intrigued by the idea of this film. Later this afternoon i'll post some stills from my film. oooops, forgot to talk about empty plates. Basically what that means is that you shoot a pass with the talent in frame doing their thing. then (or before, doesn't matter) shoot the EXACT same shot as before, just with no talent. What this gives the compositors is a plate to work with the doesn't have any actors in it. What THAT means for them, is that they can maniplute, change, work with and do whatever they want to the foreground plate (the one with the actors in it) and not have to worry about the background (because in a single plate, the talent physically hides the background from the camera). does that make sense? however...shooting a blank plate against greenscreen is useless. Thats the whole point of greenscreen. when y ou shoot against a screen, you are getting a plate that is CLEAN in the area around the talent/set so the CG or something else can be added in. There is no need to do two passes of a green screen shot. Secondlly, in order for multliple passes to really work, and be worth the effort, is if they are exactly the same. so that means either locked off camera, or motion control. you can try to jerry rig it...but it wont' be that great...and not really worth it. One more note, when shooting the talent against the screen, have someone put a grid of markers (crosses of gaff tape work fine) in an even pattern (1 meter square perhaps) this gives a reference for what is going on with the spatial relation of the shot. also, if possible, have some other objects that are green painted (like a stick or a pole or a box) at various depths through the scene, so that the compostiors/CG artists can have a great reference as to the spatial sense of the scene. Hope this all makes sense, hard to explain with just words. Keep me posted, also, this may be totally a hair brained idea, but i wold be delighted in some way to actually help out with this film, it sounds really intriguing and interesting. I may live in the states, but thats what the internet is for right? :) Regardless, good luck!

Steve Lamb

http://img520.imageshack.us/img520/3950/still13we.jpg

http://img520.imageshack.us/img520/7291/still23cn.jpg

http://img520.imageshack.us/img520/3351/still32fv.jpg

links to three pics from my film, they are in order from the "reveal" shot of machine. like a storyboard.

Steve Lamb

Chris Clarke · January 31, 2006

Hi Ben. I have a similar shoot to yours on the horizon. It's a music video set on the roof of a hotel. Lots of neon lights with a choreographed dance in the middle of it all. The background will be a city scape, maybe London, and the whole thing's set at night.

At the moment we will be shooting against a green screen on a stage with all the backgrounds being added afterwards.

Would love to hear of your experiece and any surprises of tips they came up!

Regards, Chris.