Sorry about the previous post it got posted before I was done with it.
Thank you for all your good suggestions. Probably should just buy a scoop of bait with the money instead more books!
This same question was posted on the Striper forum: http://seastriper.com/
so it got my interest and I asked the question here, I am always looking to learn a little more.
I have been looking at F/F screens since the screens replaced the roles of paper and also the rotating flashers. Some of you surly remember those. Actually the Lorance 15A paper graph was an excellent machine and returned the typical arches for fish passing under the boat, I don't see those with my RM high definition as well.
I also attended Mark Wisch's seminar on the F/F It was great, and gave very good pointers especially on using the 50 and 200 HZ.
Also have used a Under Water Camera on a long cable to see what the F/F showed.
But there is still lots of interpretation and uncertainty going on.
So if someone has video of the F/F with a video from an underwater camera, i would be willing to spend a few dollars on that.