Undoubtedly Photoshop is by far the most widespread photo editing program. But this is a very expensive program, and it can also be quite daunting to learn how to use properly. I have for years been using Picture Window Pro, a very capable and quite inexpensive program (USD 89.95 for the pro version). It does everything a photograper would want to do, without all the graphical production stuff that Photoshop users pay for but have no need for. For a quite comprehensible tutorial on the use of PWP, see Norman Koren's pages. In this tutorial, I will concentrate on the use of PWP for post-editing panoramas after they have been created in PTGui.
Use your favorite RAW converter (you are using RAW, aren't you?) to create high quality JPEGs. TIFF will give marginally better result, but I don't find that the quality increase justifies the extra time and disk space needed. All pictures must be taken in manual mode, and they must all be converted with the same settings for exposure, contrast and colour temperature.
When the panorama is ready for rendering, select file format 'JPEG', and layers 'Blended and layers'. Uncheck 'Color correct layers' (you don't want the colour ghosts that can appear in a layer where there are objects in the other layers that are missing in this layer). The layers are needed if you need to edit seams in the finished panorama. In addition to the blended panorama, there will be one file for each image used to create the panorama.
The blended panorama. Notice the fault in the middle - the runner has lost his leg. In addition, there is another runner visible through the lamp post - this is distracting, so this runner will be removed.
The layer that contains the complete runner. When there is something in the blended panorama that needs adding to (the missing leg), select the layer with the complete object (runner) to create a mask from.
Create a mask by pressing 'Mask' -> 'New'. I find 'Spline' (5th box on lower row) easiest to use.
Create an outline around the complete runner (including his shadow). Only the missing part is really needed, but just to make sure the complete runner will look good, I created a mask covering him completely. Press 'Apply' when the mask is complete.
At this point I would normally feather the mask (blur the outline), but I will work more with it first, so press 'OK' to complete creating the mask.
Now I want to remove the runner behind the lamp post. This time I will work with a mask over the blended panorama, but it so happens that it is the same layer that will be used for correcting, so the mask that was created in the previous step will be added to.
The finishing touch to the mask will be to 'feather' it. This will create a gradual zone for any transformation this mask is used for, from full effect to no effect. In this case a feather width of 32 was used.
Now the mask can be put to use. Select the blended panorama, and press 'Transformation' -> 'Composite...'. Select the mask in the amount box to the right of the amount scale, and select the overlay in the 'Overlay' box. Press 'OK' to complete the composite, or press 'Preview' first to have a look.
A section of the finished composite. This sequence of operations must be done for each seam that needs editing. If you do it in several sittings, the intermediate stages should be saved as TIFF so that the panorama will not suffer any repeated JPEG compression losses.
Do local contrast enhancement and sharpening to taste, and save the panorama for the next step of the process.
The nadir shot can be done hand held if there is enough light. Remove the tripod, and try to hold the camera at the same height. It is not important to hold it exactly level, a little tilt will be corrected automatically.
The camera/lens combination I use, Canon EOS 400D with a Sigma 8mm F3.5 EX DG, show only slight vignetting. The RAW image should be converted 0.2 stop darker than the rest. But it does show a noticable shift in colour temperature, so the nadir shot should be converted with a colour temperature that is 250K lower than the rest.
De-fish the image using PTGui (save the settings that were calculated while creating the panorama).
The equirectangular panorama must now be converted to cube faces. Pano2QTVR may be used. Create a mask for the cube face containing the tripod, covering the tripod and any shadow that may be present.
The center of the ground shot will normally be sharper than the nadir cube face (which gets its image data from the edges of the fisheye lens). By sharpening the equirectangular panorama suitably, and not sharpen the ground shot, this difference will be eliminated in the final movie.
(For this panorama no zenith shot was taken, the zenith hole was simply cloned shut in the zenith cube face.)
The composite dialog is used to combine the pictures. Press 'Transformation' -> 'Composite...'. Select the mask in the amount box to the right of the amount scale, and select the overlay (the de-fished ground shot) in the 'Overlay' box. In 'Alignment', select 4-point (perspective warp).
Now you must identify the same 4 points in the cube face and the overlay. Initially these points are placed one at each corner. Just drag each one to the same point in both windows. You may magnify each window at will, to position each point with as great precision as possible. There is a 'Refine' button that may help, but I don't normally get much help from this.
When the 4 points are placed correctly (check the preview), press 'OK' to do the composite. The overlay will now be scaled, rotated and warped to fit exactly, with no further work needed. Press 'OK' to complete the composite.
If any further editing needs to be done (brightness adjustment, colour correction, sharpening, blurring), use the same mask. The composite in this tutorial is so close, that no further work was deemed necessary.
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