What is the focal length and sensor width of the perspective Camera(s)?

[micaeltchapmi]

Hi,

I want to reproduce the perspective images in Blender and I want to know what is the focal length and sensor width of the cameras you used to render these images. Can you please provide me with this information?

Thanks,

Micael

[bertjiazheng]

Hi Micael,

The camera information is provided in _camerapose.txt, please refer to data_organization.md for more details. You can get the intrinsic information via parse_camera_info.

Best, Jia

[micaeltchapmi]

Hi Jia,

Thanks for your quick response. I used the information from parse_camera_info to set the camera extrinsics and I would like to calculate the focal length of the camera using this formula: focal_length =(0.5*SensorWidth)/TAN((0.5*HorzFieldOfView)/57.296) I got the horizontal field of view from parse_camera_info but I don't have information about the camera sensor width. Can you provide that information?

Thanks,

Micael

[bertjiazheng]

The resolution of the perspective image is 720x1280.

[micaeltchapmi]

Thanks for your reply Jia. I was looking for how to get the sensor width and focal length from the intrinsics and I found it here https://blender.stackexchange.com/a/40835/99643 . The equations of interest were:

sensor_width_in_mm = 𝐾[1,1]∗𝐾[0,2]/(𝐾[0,0]∗𝐾[1,2]) 𝑠𝑢 = resolution_𝑥_in_px / sensor_width_in_mm focal_length_in_mm = 𝐾[0,0] / 𝑠𝑢

Putting it here in case someone needs this.