My Autopano Pro forum

mgg310 wrote:

The second image is using the default detection settings EXCEPT Auto Color Correction disabled. In this image the left hand side is perfectly fine.

I bet you used auto exposure when shooting. If I'm right, this explains differences between Auto Color Correction enabled or disabled.

- Enabled causes APP compensating for exposure differences between shots. For that it haves to decide of a "reference shot" where it automatically places a "yellow anchor" (for more about anchors see the wiki) and then adjusts the other shots accordingly. As any known software does, APP don't have artistic talent and often don't select the best possible yellow anchor placement. If you decide by yourself of the location of the yellow anchor (or use 2 yellow anchors rather than a single one) you will get much better results using AUTO mode for panos where the lighting condition vary widely from shot to shot and the camera auto-exposure mode is used.

- Disabled causes some sort of "spacial HDR compensation" (by the camera rather than by APP, that is.) APP don't adjust exposure between shots but Smartblend is smart enough to conceal the brisk variations that could occur between shots. The result often looks fine...

Conclusion: for single row panos where lighting intensity varies widely, some sort of "spacial HDR compensation" is possible where the camera decides of the right exposure for each of the source images and where Smartblend acts as a local tone mapping filter. This is only possible for panoramas, impossible for ordinary HDR shots, easier for single row panoramas. Because the camera takes care of the automatic adjustments, APP NONE LDR option or manual yellow anchor(s) placement is to be used. Having a high percentage of overlap between shots helps to keep the variation from one shot to the next low enough. (I often use this method for circular 360° panos.)

Last edited by GURL (2008-10-01 13:02:48)

mgg310 wrote:

You were right that I used auto exposure when shooting.  I think that maybe I was a bit confused by terminology. I didn't expect Auto Color Correction to have such an effect on exposure levels. I turned Auto Color Correction off, and Auto Levels on and the result was 'identical' to both being off.

Auto Color Correction changes brighteness, contrast and color balance (that is both exposure and white blance.)
Auto Levels was renamed as Automatic Horizon to avoid confusion (...but you are not using one of the APP most recent versions!)

mgg310 wrote:

As the Auto Color Correction can have such a dramatic effect I think that the default setting should be disabled.

Though APP "auto exposure mode" is not perfect it tends to give better results than the other option. By the way you could upload your source images on the FTP server (as described there: http://www.autopano.net/forum/t766-ftp-server) and ask why AUTO mode gave such a poor result (this could result, for example, from your source images EXIF data being misinterpreted.)
.

Forget APG 1.90 Alpha X for now - CP detection is known still to have some major bugs.

Stick with APP 1.4.2.

Last edited by mediavets (2008-10-03 10:47:58)