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Chroma keying – filming – general advice
VMS10 Movie studio user.
Looking to try some chroma keying for a local amateur show where we need some footage of talent (that we will be shooting) overlaid on some images and background footage.
I have experimented with the chroma keyer in VMS, but this will be the first time I have tried to shoot talent, key it and overlay it on some images/footage. I will be experimenting over the next few weeks and so would welcome any general advice/comments/gotchas from people who have done this already.
I would expecially welcome any advice on the setup of the green screen. I am assuming that there will be a large backdrop which we will make from green cloth, which will need to be stretched tight. Lighting this will be key, from what I understand. Any suggestions here would be especially welcome – what type of light to use, from what positions etc.
When shooting, are there any specific tricks in terms of camera angles, distance etc that I should watch out for.
Also, when it comes to talent, apart from not wearing green – is there anything else that I should be aware of.
These questions may be far too general, so again any pointers to articles/tutorials etc would be very welcome.
Thank you
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6 Replies
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Vegas has never had a great keyer. You can get some pretty good results by lighting and position and the type of edges of your subject. Hard and nonreflective edges are your frined. Soft and reflective edges like shiny black clothes or edges like fluffy blonde hair are impossible to relealisticly key with this pluggin. Light the greenscreen evenly with no shadows or wrinkles, put as much space between your subject and the green screen as possible to eliminate green spill on the edges of your subject as Vegas’s keyer has no spill suppresion, and backlight your subject well. This will reduce the spill. Also if your keying DV footage, put a chroma blur filter set to medium before the chromakey filter in the pluggin chain. Spill is the biggest problem with this chromakey pluggin so if you can light things so there’s no spill, you can get a good key.
Hope this helps, Danny Hays -
Oh yea, Make sure you have the camera in manual mode and white balance it to a true white surface, like a white posterboard in the spot you will be shooting in.
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Also, you can use masking to give the somewhat questionable Vegas chroma key plug-in a little help. Unless you have perfect lighting, you may find the keying shifts a little… you can play with the plug-in to find the optimal setting.
But in many cases, you’re shooting a talking head or some other stationary subject against the green screen. In about a minute, you can create a mask for that subject. At that point, you’re only dealing with keying on the immediate surroundings, not the entire backdrop. This may be much easier than getting the whole backdrop clean.
-Dave
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Folks,
Thanks for the very helpful info so far. From further investigation, and also from the comments here, it would appear that the standard chromakeyer in Vegas may not be the best? Would there be third-party plugins that might be recommended? If it were to make much of a difference I would invest in such a plug-in, as I would expect to be using it on an on-going basis. However, if the general belief is that the included keyer is about as good as one gets then I will stick with that.
Thank again.
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[Stewart Bourke] ” Would there be third-party plugins that might be recommended?”
The Chroma keyer in Boris Continuum Complete 7 is one of the best. You can buy it separately as a Continuum Unit if you can’t afford the whole BCC7 suite. Download the trial and check it out. If you can’t afford the Boris Chroma Keyer, the next best for Vegas Pro is the one in NewBlue FX Video Essentials II. The entire VEII set of plug-ins are great so you are getting a lot more than just a chroma keyer.
[Stewart Bourke] “However, if the general belief is that the included keyer is about as good as one gets then I will stick with that.”
The chroma key plug-in in Vegas is 10 year old technology and it’s about as basic as it gets. It’ll do the job if you light things well and control spill. I would try and use it first before going out and buying something else. Only buy something if you need it.
Here are two excellent articles about using the Sony Chroma Key and setting up a chroma key shoot by Keith Kolbo:
Using Chroma Key and Chroma Blur in Sony Vegas
Tight Budget Chroma Key LightingIMHO, these are “must reads’ for anyone doing chroma key in Vegas Pro. Good Luck.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Keep your subject several feet away from the green screen and be sure to use a backlight. I’ve used Vegas Pro 8 & 10 with great success using the chroma key plug-in.
Making your own green screen?? I bought a large paper roll backdrop from a local camera/photo store for $60. It’s chroma key green, about 9 ft wide and you just roll out the amount needed for your shot composition. If it gets wrinkled or damaged, cut off the damaged area and unroll more of the paper. It works really nice.
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