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High noise and blocking on green screen...
  • Hey, I was curious if someone could help me. I am new, and and don't know much about video..my Gh2 is producing a lot of noise, grain, and (I think you call it...) blocking on a green screen I am trying to do. My ISO is set at the lowest setting, the scene is brightly lit, and my histogram says the situation is perfect, so I am not sure what is going on.

    Would a bit rate hack help solve this problem? Is this an encoding problem? Any help/advice would be appreciated.

  • 8 Replies sorted by
  • I would try an intra frame hack like Moon T7 (which is amazing), and/or try using Motion JPEG (as apposed to the AVCHD codec), then compare everything to see which yields the best results. Good luck!

  • I have not had much luck with the hacks, as of yet. I need spanning, and the only hack I have been able to get to span, was an older 44mb/s hack. I just (right before I posted this), downloaded Sanity 5.1 to try that... does Moon T7 have full spanning capabilities?

  • Just last weekend I shot a full 60 minute performance with Moon T7 on two cameras - everything spanned no problem, but I was using 720p (60fps was requested). I've not done extensive testing with 1080p spanning on T7 yet though. Also, I only use Extreme PRO cards, so that might be a factor, I'm not sure. I'm certainly no expert on this subject, but I thought I'd give you my two cents!

  • You need a high bitrate, Intra patch if you want to do green screen with this camera. The smaller ones are not going to work well. Then if you need spanning, you have to get the 95mb/s, 64GB Extreme Pro card. You really don't have a choice. Either do that or use another camera. Also it looks like your screen is not properly lit. You need to look at a false color monitor and make sure you have the same exposure across the whole screen.

    Also Sanity is not going to get you anywhere close to where you need to be.

  • Sandisk Extreme 64 / 45 mb/s is also good for moon T7 and spanning

  • I have used Drewnet T9 in both 720 and 24p 1080 and it works fine. I use After Effects for green screen and use keylight. I also use a really useful plugin called Key correct which has a deartifacter which smooths some of the issues you have with encoded AVCHD footage. If you are using the camera un hacked then I anticipate you would have a lot of blockiness.

  • Also try to shoot with a higher shutter (means more light). This cuts down on the blur of fast moving objects which helps when keying heavily compressed footage.

  • Thanks for the advice. Vichariss, which patch would you recommend? I think I might try Moon T7- What is irritating about this is that my Canon t3i, on the same green screen, looks perfect, but of course is limited in record time. And other than the Green screen, in my opinion, the picture quality is not nearly as good...