Thank you and totally new to blue / green screens Help

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The Duke
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Joined: Sep 1 2001

Hi All

I have over the last 6-8 months been learning how to use Premier and my Sony D8 camera. Since I joined this board I have learned a huge amount - so a big thank you to all that has helped me. I have produced and edited my own wedding video which was in Mexico. I shot 9 hours of footage over three weeks and edited it down to 2 hours and I have made a very short movie based on mission possible that was used to get one of my friends through the initial heat of Big Brother 3.

The next thing I am trying to learn is how to do a blue or green screen shots. I wanted to try and recreate the Milenium Falcon Flying through the sky as if it was actually there just ti get the hang of things. I know that I should use a blue or green backdrop but what do I do from there? I have heard things that you need to use chroma-keying or something like that. Totally confused????

Has anyone attempted this or a similar project?

Also is a green screen better than blue for my Sony trv-320e D8 camera.

I would realy appreciate some help in to getting started on this area of editing as what you see them doing with screens on movies looks so cool. I know I will never get that sort of quality but I want to give it a go.

Many thanks again

The Duke

sharkey
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Joined: Apr 19 2002

Hi Duke

I'll try and clarify a few basics for you.

Chroma-keying is the process by which you separate the foreground (stuff you want to keep, like actors etc) from a uniformly coloured background which you then replace with something else (like sky footage in your example of the millennium falcon).

Brightly coloured blue and green screens are used for chroma keying because such saturated colours are unlikely to appear in the foreground elements, and so it's easy to discern which is which.

There has been much discussion on why green screens are technically (slightly) better than blue for DV, but as a first timer there are far more important things for you to consider:

- Make sure the coloured background is well and evenly lit.

- Make sure there are no foreground objects that are the same or similar colours to the background (this is really the factor most likely to decide your choice between blue and green for your chroma screen)

- Keep your foreground objects as far away from the screen as possible when shooting.

It is possible to use Premiere's transparency settings for basic chroma-keying - it's a while now since I tried it but basically, you put your background shot on V1, then overlay at the same place your blue/green screen footage on V2. Then if you right click the top layer, in video options there is a choice named Transparency. Select this and you should be able to set up your basic chroma-key from the transparency dialog box.

For more professional results a more specialised FX package like After Effects, Commotion or Combustion will provide much more control and flexibility to your keying.

The best tutorials I've found on this subject are by Barend Onneweer at the after fx section of creativecow.net, they do go into some detail but will certainly point you in the right direction.

Hope this helps

Sharkey

[This message has been edited by sharkey (edited 01 May 2002).]

The Duke
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Joined: Sep 1 2001

Hi Sharkey,

Thanks for the info.....

This has cleared things up a bit. I tried a very basic thing were I shot a yellow lighter against a blue folder and then overlayed it to appear in the sky. Not a perfect result but a start anyway.

Would you know what the best way to shoot the falcon was. I imagine that I or a friend woould have to give it motion by holding it and moving it.

Do I also have to move the camera to give the impression of motion?

Do I need to film the model in a particular way to get it to look life size?

Finally If someone is holding the ship how do I get them to out of the shot?

Sorry for all the questions but I am so new to this side of editing.

Many thanks again

The duke

Christian Lett
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Joined: Apr 26 1999

Hi Duke,

If you've got someone holding and moving your Falcon, you'll have to erase their arm, etc. from the shot when you come to your composit. Dressing them in the same colour as the background will help but unless you're using dedicated chromakeying software you'll probably have your work cut out painting over each frame to get rid of them.

In my short "Kung Fu Movie" (which is on my website) my mate Pete was sitting on a stool in front of our bluescreen (a not-very suitable piece of blue cloth) holding a pose like he was doing a flying kick. I didn't have the time to erase the stool on all of the frames so I ended up with just five frames that I repeated. Looks crap but works for comedy effect! Plus Pete was wearing blue jeans, which didn't help! The "POV" shot of Pete's leg flying towards my head was a much more successful bluescreen shot, though.

Anyway, back to your problem... I'd move the camera around the model to minimise the amount of painting in post production. You'll need to make sure your blue/green screen extends far enough around to always be in shot and this in itself will make lighting it more tricky. The other problem will be shooting your back plate (i.e. the sky) to match the movement of the Falcon. Professionally the FX houses use motion control rigs to allow repeated camera movements on all three axes but, as I've been reliably informed, they're very expensive and very unreliable.

Good luck with your project,

Christian.
http://www.quarterlightpictures.com

Christian Lett After Effects and Maya Artist www.quarterlightpictures.com

Mad_mardy
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Joined: Oct 19 2000

you need to mount the ship on strings (cliche i know) then use the camera to create movement, use a monitor to view whilr you shoot.
And don't go to fast that will look wrong

System 1: AMD X6 2.8, M4A79 Deluxe, 4GB DDR2, ATI HD4870 1GB DDR 3, 2TB total drive space, Matrox RTX 2, Premiere Pro CS4

System 2: AMD X2 5600, M2NPV-VM, 2GB DDR2, Geforce 8600GT 256 DDR 3, 450GB Total drive space, RTX100 with Premiere Pro 2

Camera's: JVC HD200, JVC HD101, 2X Sony HC62

The Duke
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Joined: Sep 1 2001

Hi There

Many thanks for the advice, incidentally Christian, I tried to get on to your website but I can't get access to it. I tried to find it through google but no joy. Is there problems with the site? I wanted to check out your kung fu footage.

Many thanks

The Duke

sharkey
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Joined: Apr 19 2002

For the best possible results when trying effects shots involving flying spaceships and suchlike I'd definitely recommend dabbling in a bit of CG.

3D programs like MAX or Maya look a bit daunting at first but if you stick at it for a while it's not that hard to create a decent animation with downloaded models. It's also much easier to include nifty stuff like camera moves in tandem with subject moves, and you can easily add effects like glowing engines.

You can also output an animation with its own alpha channel and therefore get a perfect key over your background without the need for bluescreen techniques.

Maya has just been released as a full-featured free download, the only restriction is that you can't use it to create commercial work. However, it's a great way to learn the ropes of a 3D package if you're starting out. I think it's also on the coverdisc of 3d World magazine this month.

There are loads of great models available for download on the internet, including I dare say several Millennium Falcons!!

Sharkey

Mad_mardy
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Joined: Oct 19 2000

the problem is a lot of cg stuff just looks like er.. CG
you can't beat a well done model shot

System 1: AMD X6 2.8, M4A79 Deluxe, 4GB DDR2, ATI HD4870 1GB DDR 3, 2TB total drive space, Matrox RTX 2, Premiere Pro CS4

System 2: AMD X2 5600, M2NPV-VM, 2GB DDR2, Geforce 8600GT 256 DDR 3, 450GB Total drive space, RTX100 with Premiere Pro 2

Camera's: JVC HD200, JVC HD101, 2X Sony HC62

The Duke
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Joined: Sep 1 2001

Hi

I am at present downloading Maya and some models of ships. I have no idea what I am doing so I am going to experiment with both formats to see what is best. This project started as a bit of fun but now I am in the big bad world of blue screen and now I am looking at CGI as well???? I wonder if I have bitten off too much???? Wish me luck!!

I really really appreciate your input, if you have any more ideas please let me know. I will keep you up to date on my progress.

Kind Regards

The Duke

OH, By the way have any of you done anything like this before?? or something similar?

The Duke
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Joined: Sep 1 2001

Hi

I have been searching for spaceship models that can be used in the Maya format, however all I seem to be able to find is the extensions for lightwave,3ds,dxf. Does anyone know what the extension for Maya files ? (still downloading it at the moment).

Sorry if this is a simple question

Many thanks

The Duke