Welcome to a new installment of the video tutorials for shooting and stitching 360° panoramas. In today’s issue you will learn all tricks and techniques for erasing nadir errors. Nadir is the “down” side of the spherical panorama, the part you see when you look directly down. Many errors can be seen in this part of your panoramas when you are not careful, including stitching errors, your tripod, your legs, shadows, etc. It is very helpful to know how to fix these problems.
The caveat of editing nadir and zenith (the bottom and top part of your panorama) lies in the fact that in the flat version your photo is very distorted in these areas – which is highlighted in the attached photo by red boundaries. See also the interactive version of the photo.
Spherical panorama in the equirectlangular projection with highlighted distortion zones
Therefore it is almost impossible to fix the photo using your normal photo editing techniques, e.g. Photoshop. If you try it you will never be able to follow the distortion properly and it will almost surely result in very weird artifacts in your final panorama. I even encourage you to try it so you know what I’m talking about.
In the following video Florian Knorn will show you two nadir fixing methods which first unwrap the nadir so you can fix it easily. You will need PTGUI and Photoshop to try the things covered in the video.
Video: 360×180° Panorama Tutorial – Pt.5: Editing the Nadir
The second easy option you have for fixing the nadir is to use the software called Pano2VR (paid). This software is great for extracting arbitrary views from your panorama, exporting them as tiff files which you can edit in Photoshop, and then reimporting these patched files back to your panorama. I use this software for most of my patching and I definitely recommend it.
This article is a part of the Introduction to Effective 360° Panoramic Photography series.