My screens generally look like Firetiger's on my HDS-7 gen2. The perch look like a long continuous line most of the time because your'e sitting still at anchor. Looks totally different if you are moving and looking for them. The fish will appear more separated since they are only in the sonar cone a short time. I'll tell you what helped me though, and this probably sounds dumb. I took a 20oz soda bottle and filled it with sand. I figure that is about the size of a decent perch. I tied it to a string and dropped it over and moved it around the sonar cone to get a feel for what a 8"-9" target looks like on the bottom. You can play around with it at different distances off the bottom. I know, sort of lame but it helped me visualize what I'm seeing better. Has to be a fairly calm day though and it works easier if your'e anchored or drifting real slow. Here are a couple screen shots. Not very good ones but you get the idea.Good luck.