View Full Version : how do you edit the nadir after shooting by NN5?

06-24-2009, 06:00 PM
Hi, I'm going to buy NN5, before I goes, I would like to know how you edit the NN5 (I'm a pc user) in general?

I used to shoot VR by handheld, not sure how I could effectively remove the tripod image which is supposed to be shown at the nadir.


John Houghton
06-24-2009, 11:25 PM
There are many ways of patching the nadir. Most of the techniques extract a rectilinear view of the nadir from the stitched equirectangular image. That view is then edited in Photoshop and is then merged back into to the original panorama. Some examples:

The whole thing can be done with the Photoshop plugins by Rune Spaans downloadable from http://www.superrune.com/technical/software_spheretocubic.php.

Another popular method is to generate 6 cubic tiles from the equirectangular image, edit the one containing the nadir view, and then rebuild the equirectangular image from the edited tiles. The cubic tiles can be generated with Pano2QTVR (free version) or Pano2VR.

Pano2VR has an editing feature that allows any rectilinear view to be extracted from the equirectangular image for editing in Photoshop and to be merged back into the original panorama.

A useful trick with PTGui is to incorporate the handheld nadir in the full panorama project, where it aligns only approximately with all the other images. You then generate two stitched equirectangular images. One containing the main panorama images and the other containing just the nadir. Rectilinear views from each equirectangular image can then be generated for merging in Photoshop. The merging is then comparatively easy as the images will already match reasonably well (and a fisheye nadir will of course be defished by PTGui like all the other shots).

PTGui Pro has the very useful Viewpoint feature that enables a handheld nadir to be stitched directly into the panorama along with all the other shots. The perspectives in the nadir will be adjusted to compensate for the different viewpoint of the shot. This only works when the nadir area is a plane surface (not necessarily exactly horizontal), but therefore covers most cases. There's a tutorial on the PTGui web site and another at http://www.johnhpanos.com/ptgvpt.htm.


06-29-2009, 12:28 AM
Hey John,
great thanks for the tips.

Among all 3 solutions (ps plugin, ptgui and pano2QTVR) the Photoshop plugins seems to be the greatest to work with.
Do you often use this plugin over other 2 solutions? I found the quality of the equirectangular image after the merging of 6 cubic tiles in pano2QTVR becomes not really sharp... and the control pt setting in ptgui take a bit long time (and my result is no good as I used to shoot handheld). that's why I finally go for the photoshop plugin.

happy to hear other solution (if any, but indeed, the ps plugin is already very great, thanks!)

John Houghton
06-29-2009, 04:32 AM
Among all 3 solutions (ps plugin, ptgui and pano2QTVR) the Photoshop plugins seems to be the greatest to work with.
Do you often use this plugin over other 2 solutions?

Actually, I don't usually use any of them. My own preference is for PTEditor from the Panorama Tools package. It does have its limitations - max size around 8000x4000 and 8bit only - but it maintains image quality rather better than most of the other solutions. I'm used to it, having used it for many years. The Panoools wiki has a section on nadir patching: http://wiki.panotools.org/Tutorials#Zenith_and_Nadir_retouching.