Keying problem

Hi all,
I have a problem when shooting a scene that includes a laptop computer and keyboard - against a green screen. The laptop is off, but the keyboard is in shot - and shimmers and distorts, no matter what key settings are used.
I appreciate any advice....


  • AxelWilkinson
    AxelWilkinson Posts: 5,255 Staff
    If we can see the footage, it would be very helpful in determining the cause of the problem.
  • Thanks Axel - link to the problem shot is here:
  • rgbii
    rgbii Posts: 960 Just Starting Out
    Just guessing, some light bounced off the green screen and reflected off the laptop and it looks like the mic base too. Do they have a green tint to them?
    Since they are not moving, should be easy to use a mask to take care of it.
  • AxelWilkinson
    AxelWilkinson Posts: 5,255 Staff
    I would agree with rgbii - it looks like part of the keyboard is being keyed out, which would indicate that it contains the same shade of green that the key is removing. Most likely, this is due to reflected green being present there. How far is the keyboard of the laptop from the greenscreen, when you shot that? Try to keep your subject at least 6 feet away from the green, and it will help keep the reflections down.
    I'd recommend adjusting the key a bit more to improve the results if possible, or just using masks to retain those areas that are wobbly in the key. Also, I notice a bit of an outline around the edges of your subjects, you might want to adjust the key a bit more to try remove that as well. What sort of Key are you using, and what adjustments have you made to it so far?
  • Thanks guys - I appreciate your comments. The laptop and mic base are both reflective and were probably about 4 feet from the green screen. So yes - reflected light. I've substituted a different background which is better at hiding the fault:
    For shot three (which features a few times) - keying settings were Min:0.71 Max 0.91 Gamma 1.00
    I'm not familiar with masking techniques, so I'd prefer to make the reflection less obvious using keying settings.
  • AxelWilkinson
    AxelWilkinson Posts: 5,255 Staff
    Masking is a pretty vital part of the basic keying process, and is relatively simple, so I'd recommend taking a look into it. Obviously you also want to dial in the Key settings as best you can, but Masks are often a critical element in the process.