I was looking for posts on hdr video and put that in the search string and got all posts on hdr, mostly hdr photography and all posts on video. I remembered that to narrow it down you put "" around your string, then the exact phrase only will come up. "hdr video". Saves lots of sorting thru unnecessary threads. For the few who don't already know this.
Click the "advanced search" option under the search box, and you can narrow the results down by, thread title, user, sort order, specific board(s).