Opencv 3.1 capture from multiple cameras.

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I'm using 2 Logitech C170 usb webcams connected to USB 3.0 ports on my front panel on Windows 10 Opencv 3.1 Visual Studio 2015. I have no problem getting image from one camera at a time either 0 or 1 but while I'm trying to get both at the same time i get a message:

R doesn't work

in console which is linked to second camera not working in the same time, followed by error:

OpenCV Error: Assertion failed (size.width>0 && size.height>0) in cv::imshow

Code I'm using:

#include <opencv2\opencv.hpp>
#include <opencv\highgui.h>

using namespace cv;
using namespace std;

int main()
{
    VideoCapture captureL(0);
    if (!captureL.isOpened()) cout << "L doesn't work" << endl;
    VideoCapture captureR(1);
    if (!captureR.isOpened()) cout << "R doesn't work" << endl;

    Mat imageL, imageR;

    while (1)
    {
        captureL >> imageL;
        captureR >> imageR;
        imshow("OriginalL", imageL);
        imshow("OriginalR", imageR);
        waitKey(1);
    }
captureL.release();
captureR.release();
return 0;
}

Is there any way to fix that? It must be possible to get multiple captures at once. Maybe I'm doing something wrong since it is the newest Opencv 3.1.