"David Harper" writes:
In the picture at:

http://celestart.com/images/publiques/15.jpg

...the general consensus seems to be that the sky is blown out.
When I do that in "AUTO" mode the sky is 255,255,255 (pure white).
This picture shows the sky at a uniform 239,239,239. Why is that?
What in-camera or post-processing did this? I have never seen that
before. To me "blown" is 255 all the way.

It does seem a little odd. There are points on the path where it goes
up to (for instance) 242,239,234. Though I notice the mean of that
triple is nonetheless still below 239. Perhaps whatever converted it
to JPEG included some poor decisions about the maximum?

--
http://www.greenend.org.uk/rjk/