These are pics of perch, some taking our bait. I don't believe you can get this good with a $200.00-$300.00 finder. This unit is a Lowrance 102c, the newer model is a 510c I think, Fishermans has them now for $499.00.
This photo shows a perch going from 50.2' up to 40' to grab a piece of discarded bait, old worm. At the bottom of the photo, the two black lines are sinker and bait, bait on the bottom. There are four perch in the photo comming up from the bottom to check things out, many times they seemed very curiuos about our sinkers. The bottom of the photo shows many perch from 48-50'

The keys; High pixel count finder, 480x480, color would be best. I think if you running 240x240, or less, it may be tough to get a good picture, zooming may help though. Turn finder to maunual mode, if your seeing little fishie shapes on the screen you've got it wrong. Turn sensitivity to maximum. Turn zoom to maximum, mine is 4x on this finder.
Smj