How can I build a lens calibration jig for HemiView?
If we have no information about a particular lens, you will have to calibrate the lens yourself.
One way of building a calibration jig is to remove the spokes from a bicycle wheel and mount the camera at the centre. The holes in the wheel rim provide calibration points at regular zenith angle spacings, so you can measure their locations on a photograph and construct an equation which relates the position on the photograph to zenith angle.
In the meantime, you could scan, threshold and align the images, and analyse them using the Linear 180 lens. If you save the image properties as .hvs files, it will be straightforward to later re-analyse the images using the correct Camera Lens equation.