I have been shooting Panoramic VR Photography since Apple introduced it in 1997. The basic idea in QTVR was that you now could make 360 degree panoramas by stitching several images together using computer software instead of using special cameras.
I have gone through two 303plus Pano heads. I shot mostly 360 Projections. Due to my desire for Spherical VRs with a zenith and nadir and having the basic hardware, I decided to modify my latest 303plus Pano Head. I needed something smaller and more versatile in close confines due to my architectural background.
This is the 303plus Head minus the Bogan 338 leveling base which I found very difficult to use.
The 303plus Head works very well with non fisheye lenses.
The length of the 303plus plates are too long and come into view using a Sigma 15mm Fisheye Lens. Finding the nodal point is not possible due to the length of the precision 303plus plates.
The first piece to be replaced was the 338 leveling base. It was replaced by the Bogan 438 level which is so easy to use and shown here.
The complete modification is shown here.
Finding the nodal point in correcting parallax is not a factor.