DSZ wrote:when setting DesiredFrameRate - shows it is deprecated
DisiredFrameRate was deprecated for a reason. The problem is that you can not just set the frame rate you want. Many USB camera drivers don't allow it all. Some provide support for it, but very limited. For example, some drivers say that for 640x480 resolution default FPS is 30, MIN is 15, MAX is 30. So you may get impression you can set anything between 15 to 30. No! They may accept either 15 or 30, and nothing in between. This confusion is partly caused by DirectShow API, which is generic to cover many different cameras. That API does not allow you to list supported frame rates. Only default, min and max. And all drivers somehow need to fit into that model.
DSZ wrote:What are the other methods I can try
Get proper cameras. Not Logitech or that sort of stuff. But something, which is aimed for proper imaging and computer vision tasks. Those will have their own APIs though.
Just to try, play with
CVSandbox for a bit. It does allow you to specify FPS (although driver may not accept - see above). See how many cameras you can get of it.