Capturing screen from iMac 27-inch, while working as external display

[marcin0903]

Is it possible to somehow capture a screen from iMac 27-inch and while it is used as external display (display for Xbox 360 - I have Kanex XD HDMI converter)?

 

[Hellhammer]

You can use screen sharing to connect to it and try to record the screen with e.g. QuickTime but I doubt it will work. There are some capture cards that let you capture your screen

 

[TMRaven]

You should have gotten a dedicated hd capture card to capture gameplay footage like that. HD-PVR is much more appropriate for that type of deal, and only costs 200.