There is a known incompatibility between these cameras and the NI-IMAQdx driver. You cannot use IMAQdx to interface with these cameras even though they work fine in the vendor's software and other DirectShow image acquisition software such as AmCap.
Check with the camera vendor to see if they have a LabVIEW DLL or SDK that can be used to interface with the camera without using the IMAQdx driver. If you are able to acquire images using the vendor's DLL, then you may be able to convert the image to the IMAQ Image datatype using the IMAQ ArrayToImage VI
so that you can still use NI's image processing functions.