There are 2 ways of spherical panorama’s nadir editing and the choice of the way depends on what technique was used when shooting:
1. The nadir frame insertion on the stage of panorama stitching.
In case when the nodal point when shooting the nadir was in the same position as when shooting the other frames, all the frames can be at once uploaded to PTGui and stitch them using the technique, which was described at the article above. This way there most likely wouldn’t be any evidence of the tripod’s presence in the panorama.
In case if the frame was taken when holding the camera in the hands, it can be stitched with the other ones using PTGui too. The way to do it is clearly illustrated in this video lesson.
However, the nadir frame insertion to PTGui often leads to the appearance of incorrect abutting joints and the other defects, which need to be retouched and that increases the time spent on the panorama production.
This variant doesn’t work with the panorama we stitched on the previous lesson because the frame was shot while holding the camera in hands and the long shadow from the tripod is visible in the frame and it’s not overlapped by the nadir frame and requires the additional retouching.
2. Nadir in the cubical panorama projection retouching.
It’s much more convenient and faster to edit the nadir (and/or zenith) in panorama convertrd to the cubical projection, using the lower (upper) face of the cube.
To delete the equipment or the black circle, located in the nadir, it’s often enough to use the standard retouching photoshop tools. In panoramas, where the retouching area is big and has a complex texture, we have to overlap nadir with a “patch” from the separately shot nadir frame.
There’re several methods to modify the panorama from the equidistant to the cubical one:
- The oldest, and, possibly, the most dated one is to do it in Pano2VR or Pano2QTVR - to convert panorama to 6 faces of the cube with the needed sides retouching. For the QTVR panorama production one can use the sides of the cube directly, or transfer them back into the equidistant projection. The disadvantage – not that effective method in terms of speed.
6 sides of the cube as separate files
The sides of the cube as one file, created in Pano2VR, as a stripe, cross and «T»
The second method - in Pano2VR with the help of Patch Panorama option; extract only the necessary side of the cube, edit it and insert it back into the panorama.
Pano2VR's Patch Tool
- The third method is to use the SuperCubic plugin for photoshop, which makes it possible to convert the polar areas of the panorama (zenith and nadir) into a flat image and vice versa. The nadir editing process with the help of this plug-in is the most effective and fast, in my opinion. But there’s a disadvantage as well – the large computer memory requirements. The plug-in can deny editing the large-sized panoramas.
SuperCubic plugin interface
Nadir before and after the process of retouching
(direct the mouse cursor at the pictures)