About the provided calibration parameters

[jingwenh]

Hi,

Thank you for this great work!

I find that in the provided calibration.json file, the fx and fy of the third camera is relatively larger than the other three cameras. I assume that the four cameras are selected with the same lenses and sensors. In this case, the four cameras are supposed to have similar intrinsics after calibration.

May I know why is that case? Does the third camera uses different lens or sensor different from the other three, or this might be a calibration error?

[ameuleman]

Hi,
We did not notice the discrepancy in focal length. We used the same hardware for all four cameras. Since it can match adequately with these parameters, I believe that changes in xi and alpha compensate for the change in focal length.