Hi Alexan
Thank you for downloading trakAxPC
When you connect your webcam, click on the Video Format Button beside the Video capture hardware dropdown area. ( see screenshot)
See wiki (there is a video included)
http://www.trakax.com/software/wiki/Category:Recording_with_the_Microphone_and_Webcam::Recording_in_from_Webcam/
Here it will bring up the properties of the webcam and you can change the frame dimension of the output. These properties are different for different webcams but there should be a dropdown box to choose your output dimension. Select the 16:9 aspect ratio setting.
Also click on the codecs button in the record window and make sure frame size dropdown box is selected to a frame dimension with an aspect ratio of 16:9 also (See screenshots)
See wiki
http://www.trakax.com/software/wiki/Category:Recording_with_the_Microphone_and_Webcam::Choosing_File_Name_Location_and_Codec_for_Audio/
I hope this helps and if you have any questions, please do not hesitate to ask
Best regards