HVX200a Green Screen Test

Had an opportunity to shoot some green screen this week. The Children’s Ministry was putting together a video and wanted a shot of Jesus giving communion. So I suggested shooting it on green screen. I’ve never been too pleased with my green screen shots that I’ve done on DV so I thought it would be a great test for the HVX200a.

We setup in our gym. It’s a big open space with no windows. Only down side is audio can come across boomy. The screen was about 15 feet from the talent, lit from the floor with a work light. Our green screen is an old fabric material. I didn’t buy it and I don’t like it. It needs a frame to be stretched out on to get rid of all the wrinkles. Talent was lit with 3 lights (key, fill and kicker). The hair light or background light really needed to be straight above him. I need to expand my light kit do some of this properly b/c you can see some spill on the right side of his face. Guess which side the kicker was on?

I brought the footage into After Effects. And in 5 minutes I pulled the key with AE and color matched the foreground to the plate with levels. Here’s the result:

This shot is 720p compressed to H.264. You can see some jagged edges on the left side of his face. I don’t know if this was me not setting the camera right or I just needed to finesse the key more in AE. Scaled down to DV, which this footage will be, it looks great. In face you can only really see what I’m talking about if you watch the clip in full screen mode.

My first impressions were that the key was very easy to pull. The quality seems great. This blows any green screen work I’ve tried in DV away. I’m not 100% with the jagged edge. I thought it would be smoother. I don’t know if that’s a camera setting or if I just need to tweak the key or do and inside/ outside key to get the smooth edge.

And Jesus seems like a giant because of how small the cup is.

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June 20, 2008. Tech Stuff, Video.

7 Comments

  1. Brent Homer replied:

    you want to know a scarry cool green screen trick?

    in FC right click on the clip you want to key and sent it to motion. Motion has this amazing magic keyer plug-in (in fcs2) that almost always does a perfect key…then you don’t have to make the AE/FCP roundtrip.

    I would be curious to know if you rekey it in motion if the fringe goes away….

    I have had great luck with green screen and HDV, but I have heard that most hdv camera’s with an hdmi out will do 4:2:2 and you will have awesome keying that way instead of off the m2t format.

    I don’t know tho, b/c I don’t have an HDMI input card into my laptop 🙂

  2. Dave replied:

    Brent,
    I shot this clip with the HVX200 in 720/30p so it’s being recorded in a 4:2:2 color format. I think that’s a big reason it keyed so easy.

    I ran this clip through Motion after your suggestion. I wasn’t thrilled with the results. The key was easy enough but the edges were a little more blocky/chunky. In AE I used levels to get the color of the foreground and background to match. I couldn’t get the same results using the levels in Motion. It could just be one of those situations where I know the tools in AE a lot better than Motion so I’m quicker with it. But Motion does render much faster.

    Thanks for the comments!!!

  3. Mike Sessler replied:

    That is a really small cup!

    The key looks a lot smoother than the ones I’ve done is DV. And I’m with you Dave, I tried really hard to like Motion, but I’ve been working in AE for so long that I just had to go back. Motion is fast and well-integrated, but it’s not AE.

    Also really liked the look you came up with for the Stephen Ministry promo. I’m borrowing that for my next interview based video…

  4. Dave C replied:

    If you haven’t tried it, I would suggest dvMatte Blast. It’s a $99 plug-in for FC and it works great. Excellent key in just about 3 clicks – and it renders really fast too. I use it daily with my HVX-200 for green screen work.

    Btw, just found your blog – keep up the great work!

  5. Joe Andolina replied:

    really nice keying job. any suggestions of the best shutter speed to shoot at? I’m about to do a greenscreen shoot with a rented HVX200a. I’ve been doing a crash course study for the camera only via the online manual. any advice would be appreciated. the shoot is this saturday. We’ll be shooting 1080i/30pn I have an understanding about the talent should be 8 to 10feet from the screen, evenly light screen, etc… Also, any particular settings in the camera recommended, as well? And how about the sharpeness setting? I understand you don’t want the sharpness up too much.

    thanks ahead of time.

  6. Dave replied:

    Joe,
    I’ve found it easier to get a key out of 720p or 1080p than interlaced footage. But that’s just me.

    Sharpness and the detail settings are going to be by eye. It’s a balance. You don’t want to accentuate the edges but you don’t want your talent too soft. This is where an external monitor that can show 1:1 pixel mapping will help.

    The rule of thumb for a 30p frame rate would be 1/60 shutter.

    But the biggest factor for a good key is setup. Making sure you’re lighting is the best it can be, the staging is good and you’re talent is not wearing the same color as the screen. Try to avoid spill and light to create a separation from the screen.

    Also if you know what your plate is, try to light to match the plate.

    As for pulling the key I like Keylight in After Effects and I’ve seen some great work with DvMatte. But the best keys are usually going to involve multiple mattes, at least an inner and outer mat.

    Good luck and I’d like to see how it comes out. Share any tips you learn on the shoot.

  7. americanmovieco replied:

    Hi,

    It is good to see so many people taking initiative and giving us a good information on green screen test. Thanks a lot for sharing it.

    A green screen is mainly an enormous cloth hung over a wall that flows continuously to the floor area covering around 3 meters of it or a wall evenly painted with green. A way to check this would be in the setting of your video camera. The zebra setting would allow you to see if you have even lighting. If the greenscreen appears to have slanting lines in the camera then you have even lighting. Another way to ensure that the screen has light; we shoot outside where the sun can easily light it uniformly.

    The video production facilities allow us to change the green portion of the first video and insert another video, image, or animation so as to make an illusory effect.

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