Question seems to pop up from time to time.... This images are showing mostly drum. But there are some crappie, catfish, and bream mixed in. 'least that's the species I caught while working a spoon in the schools I was marking....
The 2D image is from and Airmar TM185HW set to 150Hz. The downscan is coming from a 3D transducer/HDS Carbon.
Screenshot_2020-06-07_10.17.08 by Doug Wei, on Flickr
On the downscan that is what bass can look like when they're feeding. Unfortunately either these weren't bass or I couldn't get'em to bite... But this image serves to show how the downscan can seperate fish from the bottom while even a quality 2D transducer can not. After posting I realized that in the below image the downscan is coming from the 3D transducer but the 2D image is coming from the Xi5 built-in on the bow. So they are not showing the same image but it still holds true that 2D is limited in locating fish that are holding on the bottom.
Screenshot_2020-06-05_06.50.15 by Doug Wei, on Flickr
Screenshot_2020-06-03_09.26.41 by Doug Wei, on Flickr
In this image you can see where I'm lifting and dropping a 3/4oz. spoon on a school of fish. Most of those fish were ~3# drum....
Screenshot_2020-06-02_15.19.16 by Doug Wei, on Flickr
This image came from the bow HDS 9 Carbon. The left screen is coming from the Airmar TM185HW transducer set to 150Hz mounted on the transom while the right image is coming from the Xi5 built-in 83/200 transducer set to 200Hz.
Screenshot_2020-06-07_09.50.32 by Doug Wei, on Flickr
Then just for the halibut I flipped on FishReveal to see what it looked like... As a general rule I don't use FishReveal.
Screenshot_2020-06-07_12.42.59 by Doug Wei, on Flickr