8.4. Stage 4

8.4.1. Closing the sphere

I then continued with the two rows of photos taken at plus and minus 45°.

The manipulations were the same as those for the first row of photos. When I wasn't sure of a picture's correct position, I expanded the display to full screen, using the Windows→Full Screen command (keyboard shortcut: Spacebar).

In this particular panorama, one of the main problems was the presence of water! The surface of Venice's canals is seldom rough, but the reflections of the buildings—and the gondolas themselves, of course—have an annoying habit of moving in unpredictable ways. This forced Stitcher to do a lot of adjusting from one picture to the next.

One way to get a sneak peak at a stitched sectionis to launch a partial planar render with Render → Proof Preview.

For this panorama, the reflections didn't pose real difficulties during the stitching stage, though they created other problems later, as you will see. What gave me trouble was the gondola in the foreground—it moved a few inches between successive pictures. I finally wound up positioning the photograph as closely as I could by using reliable, fixed reference points (the dock and the railing) andthen forcing a stitch, using the Stitch→Force Stitch Image command (keyboard shortcut: Ctrl-Enter).

With Stitcher 4 it's very easy to see which images have been force-stitched——their thumbnails in the Image Strip have little orange markers instead of green ones.

I now had to position the final two photographs, the shots of the sky and the ground.

The zenith shot moved into place without any trouble, but the nadir was more problematic. All I knew for sure was that the lens entry point was probably off-center compared to the other photos.

If I tried to stitch the photos as is, it might trip up Stitcher. Working from this new (probably incorrect) value, the program would recalculate the focal length—and thus the positioning—of all the pictures. So I put off positioning the nadir shot, and added it later in Photoshop.

This photograph of the Orseolo Basin had a lot of contrasts—not just shapes and textures, but areas of light and dark—which influence the way colors look. Stitcher was helpful in smoothing the overall colors, and it significantly reduced the variations in brightness.

Before running a render, I needed to straighten out the panorama. I chose vertical lines I knew were correct (doorways and the corners of buildings) and drewvertical lines over them with the cursor. When I pressed Enter, Stitcher aligned the panorama automatically. If I didn't like the result, I could have started over. Once I defined the vertical lines (and therefore the horizon), the Align Panorama icon appeared at the lower right of the Stitching Window.

If I change the angle of my panorama, and therefore lose its alignment, all I have to do is click on Tools → Go Back to Defined Horizon to automatically realign the picture.