Did I do it right? S&F

85% hydration sourdough Ciabatta. 30% of flour was used in a 50% hydration preferment.

First S&F was done in the bowl with a scraper. Subsequent 3 folds were done at 30 min intervals.

http://imgur.com/xysa35l,UHI3JwW#1
http://imgur.com/xysa35l,UHI3JwW#0

I started doing the S&F technique about 8-12 months ago. I still can't believe the difference it makes to loaves!