I shot some Gigapans this weekend and my Canon Powershot G9 was acting up in a way that I’ve never seen before. The exposure seemed to vary, but in a gigapan that I shot twice, it varied on exactly the same frames. AWB was off, and exposure was on manual. I’m stumped except to thing that maybe the camera is in its death throes. . .

Here’s a screenshot of stitcher with both iterations of the Gigapan ready to stitch. Note the variations in the sky around the buildings:

http://thehardyfamily.net/filechute/exposure.jpg

I’ve seen something like this, but not as dramatically in my Canon SX10IS. You can see the subtle effect in this stitched GigaPan of Monument Valley: http://www.gigapan.org/gigapans/52690

It’s most noticeable in clear blue sky. Most other times I can’t see it.

You might also want to check out this thread on the old forums: http://forum.gigapan.org/viewtopic.php?f=6&t=736

This is Canon Digic chip’s contrast optimizer, visible where there is a transition between blue sky and horizon objects. Ron had it in his Monument Valley pan. I could not find a control on the G9 to turn it off. The control on Ron’s SX10 is called i-Contrast. It is on by default. On my T2i it has 4 levels and is called Auto Lighting Optimizer. I discovered this with my first outdoor test gigapan and have seen it on many uploaded pans. Unfortunately, I think the only workaround for the G9 is to use RAW.

Dave

That would make sense – this is the first time in a long while that I haven’t shot RAW. :-/