I guess it depends how much the sky is blown out as to how much detail can be rescued. Also another thing to be said with using filters is the mere act of dropping the filter in and lining it up makes you re-check your composition.
Also I do want to get as much right in camera as I would rather be out in the fresh air than sat at my desk editing photos.
Well that's my thoughts I suspect you will have a good debate on your hands so thanks for that
You could cause even more debate by doing another thread titled "Throw away your hot shoe spirit level" and then go on about the straighten tool
