The video dialog 

if your interferometer is ZYGO or Fuji, you should use the NTSC mode.

Click the Interfero tab to change the software to interferogram interface

On the right side, you will find the video operation buttons

[video on]: Turn on the video device.

[Calibration Switch]: Change the ports of the video device AV1 to AV2 or AV2 to AV1. SHORT KEY [TAB]

[Capture Picture]: Get the video to picture used to analysis. SHORT KEY [SPACE]

[Analysis]: Calculate the finger to wavefront map to analysis the result.  SHORT KEY [ENTER]

Exchange the video from right top position to fit the screen. SHORT KEY [F4]

Resize the selection picture. SHORT KEY [F3]