Estimate Rotation and translation from 2 camera facing each other

Question

I am new to image processing and I have limited knowledge on OpenCV and other image processing tools. I have two cameras facing each other and both cameras are identical, but the lenses are different. I image two different features on both the cameras simultaneously. The features are 2D and not a volume or 3D phenomenon so I don't have to reconstruct to 3D or anything. For now, I simply want to compare the two phenomenon by overlaying two images form the camera.

To do this I take image of a transparent target (something like a checkerboard pattern) and I want to adjust the rotation and translation between both the images. How do we do that in python either by using open cv or just using modules such as SciPy and NumPy.

I have briefly read about OpenCV camera calibration methods using cv:: cameracalib() which requires for me to get the image of target at different degree of rotation and translation to calibrate. and in my case this is out of scope and I only have the checkerboard pattern target to work with. Please let me know the algorithm or method that I can use to do this.

Thanks:)