Controlling automatic exposure correction


“My panorama is too bright or dark overall”
“My panorama is washed out”
“The sky is muddy”
“The picture looks posterized”

The automatic exposure correction option of The Panorama Factory normally does a nice job of balancing the brightness and contrast of the final stitched image.  Occasionally, however, the final image has objectionable color shifts or desaturation effects.

Happily, a single approach may be used to fix any of these problems. Color problems like these occasionally result from the automatic exposure matching or the automatic exposure correction performed by The Panorama Factory.

The Enable exposure matching setting works well for many images, but not for all. For example, it may not be possible to exposure match a 360 degree panorama that includes images into deep shadow and into bright sun (maybe including the sun itself).

The Enable exposure correction function tries to balance the resulting image to a pleasing range of brightnesses including black and white (it is a histogram stretching function). Sometimes this results in poor rendering of some areas of the image, particularly for especially dark images (e.g. night scenes) or for images with a wide variation from bright to dark.

When your panorama has one or more of these problems, you should removing the checkmark from both Enable exposure matching and Enable exposure correction to see what happens. You control them on Wizard step 4/9 – Control image quality or on the Blending properties dialog box (Tools menu).

Then you should try selecting Enable exposure matching by itself and then Enable exposure correction by itself. After stitching (with the Wizard or the Classic interface) but before closing the project, you can change these settings with the Blending properties dialog box (Tools menu). The Panorama Factory will recalculate the image without repeating the whole stitching process. If you are using the Wizard, be sure to press the Done button before trying to use the Blending properties dialog box.

If removing the checkmark from Enable exposure matching produces an image with unacceptable brightness variations, you may want to try manually adjusting the exposure matching. Read “Adjusting exposure matching and brightness falloff” in this chapter for step-by-step instructions about adjusting the exposure matching. (Please note that Enable exposure matching must be selected before you can manually adjusting it.)



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Updated: March 6, 2009