Green screen newbie.....

[Randall Allen]

We recently moved my office and added a green screen in one end of the office. Here is the first minute or 2 of our first show with it.

www.cavespringlibrary.org/c4/LibrisRoma-clip.mov

I think it turned out well for a first run. The chair and table don't fit the background and are out of scale. We shot the second show using a wrought iron bench from out in the library garden so maybe it will look better. Also, I'll go and get better background footage than we got on such short notice.

Overall I was pleased. Your comments welcomed.

Randy

[Russ Holland]

Looks great, but there is an outline around your chair, just need to change the expansion of the chroma key a little to remove it, depending on what keying program you used.

Check out video copilot for a very good green screen tutorial for After Effects and Keylight. (www.videocopilot.net)

On the whole though, you have a very neat key, well done. It's harder than it looks.

Russ

[Bert Smyth]

Randall, just wanted to say good work! Lighting for a chroma key isn't easy, and you did a really good job. Looks like the did a hell of a job on the green screen build!

[Randall Allen]

Russ, Bert:

Thanks for the kind comments. It really is harder than it looks and yet at the same time it was supprisingly easy. We use a GL-2 and Edius Pro 3.6. That paticular key was actually a combination of 3 keys. 1 all the way accross the screen from the height of the table to the bottom. Then 1 on each side (left and right) from the height of the table to the top.

The table was getting a lot of green light bounced on it so I had to isolate it and adjust the key values. Once I get better at lighting it I hope to not have to do 3 keys but for now it worked. We also learned that the green floor is not so good. I think we will be purchasing a floor rug or something to get rid of some of the green in front of the subjects.


Randy

[Brian Brown]

Very cool, Randy. Ain't chromakey fun?! Looks like you're setting up a great space for keying.

To pull easier keys, you'll definitely want to light the screen and the talent separately to avoid shadows and spill. I also found the mic placement a little too far away, picking up too much room tone. If you want to avoid a lav clipped to the talent, maybe you could get the mic up on a boom and pointed down.

Just some thoughts,
Brian Brown
BrownCow Productions

[Randall Allen]

Brian:

Thanks for looking. I appreciate your input. We have a boom and a stand for the mic but the mic weighs so much that in order to keep it out of the shot it nearly bends the pole. I know get a larger pole.....I work in a library and well TV production stuff does not rank very high in the budget areas.

Most of our stuff is done "on location" at various points and so the main camera ops hate lugging the equipment so stuff like the stand and weights for the stand get left behind. As I work on the green screen and we use it more often I'll rig an overhead spot for the mic.

Budget also has me in the lighting area I have 3 of the lights you saw in the clip. That one was actually lighting the screen. The other 2 were used 1 as a key and the last as fill I think....or it might have been as a kicker to try to get a little seperation from the screen.

I'm still learning and it will progress. Thanks for the feedback.

Randy

[Brian Brown]

Hey Randy,

I hear you on the budget thing. Totally understand. But, bear in mind, you can light the screen with just about any set of lights, as long as it's flat and even. In fact, it's best that the bulbs don't color-match the ones on your talent (daylight vs. tungsten, etc.), which means you can use fluorescent tubes, worklites, whatever. Mixing color temps between chroma and talent gives the keyer much different (i.e. better) values to work with.

Here's a shot of my last chroma setup: http://www.browncowvideo.com/svvcu/chromasetup.jpg

I used some floor lamps to light the screen, with four big tungsten-balanced CFLs. For the talent, I used a 3-light kit with daylight-balanced CFLs (two black fixtures in front, plus the hair boom). Space was obviously very tight down in my basement!

Here's the results: http://www.browncowvideo.com/svvcu/greenscreen.jpg

The finished spot is here:
http://www.browncowvideo.com/svvcu/TOM/

Granted, the keyed footage isn't the main part of the piece, but it was a very clean key and was a cinch to do (one click on Keylight in After Effects).

I'm finding it very easy to do chromakey on a budget, as long as the screen is lit well and there's good separation between the talent and the screen.

My next task will be a full-body key for a "walk-on" web video, so I'll keep 'ya posted on how that goes.

Cheers,
Brian Brown

[Randall Allen]

Your set up looks nice. I definitly like the results. I took a pic of our set up for this week's shoot but have left the cable at home to upload the pic. I'll post it soon.

I like the idea of using off temp lights and may verywell bring in some of my shop lights to see what I can do. We have the office lights but have turned them off for the last two shows. I may turn them back on as I'm getting too many shadows under the table and chairs. If only I could get the talent to stand for 30 minutes then I would not have to worry about it. ;)

Randy

[Brian Brown]

Randy, another light to consider is those cheap, worklight fluorescents. Placed vertically on a makeshift stand on each side, two-tube x four-foot or even eight-foot models (if your ceiling is high enough) would make quick work of lighting your greenscreen. The nasty "green spike" color-quality of these bulbs, usually the bane of video and film, actually helps when keying out green, I'm told.

Your space is pretty massive for keying, and looks surprisingly good for your conditions. The extra lights would just help you pull an easier key.

And, yeah, shadows are very, very bad for keying. Something immobile like a table could be readily matted out, but any shadow on the screen near the talent (and esp. those created by the talent) will lead to no shortage of woe.

Cheers,
Brian