Down Imaging Sonar
The compromise between side imaging and the usual 60/83/200 kHz transducer is the down imaging feature. By using high frequency sonar and directing the beam underneath the boat shows a high resolution view of what is underneath the boat. The Difference between the side and down imaging features is the beam direction. Side imaging allows for views to either side of the boat, down imaging gives a view directly under the boat.
Color or Gray-Scale?
Color vs Gray-Scale
One of the biggest decisions when buying a fishfinder is whether to get a color or black and white screen. Each has advantages, color provides more detail and helps interpret sonar images more accurately. Black and white is less expensive, which means that you can pickup features like down imaging and side imaging at a cheaper price. The recent tech improvements now allow for higher quality color screens at more affordable prices. So color displays are within the reach of the budget conscious fisherman.
Side Imaging Sonar
Side imaging now allows for ultra high resolution view of what is underneath your boat. By using high frequency transducers, they are able to beam sonar at high rates which gives a much more detailed sonar image. The image is presented with views of the sonar and port sides of the boat. These images show the contour and structure that is under the boat. Each brand offers a version, all of which are very high quality.
What Sonar Frequency?
What Frequency Sonar?
There are three different situations in which sonar frequencies have been developed. The first are the regular frequencies which operate in 50, 60, 83, and 200 kHz. These are the most popular, and are available on almost all fishfinder models. Side and down imaging sonar frequencies use a higher frequency. The usual frequencies here are 455, 600, and 800 kHz. Down imaging usually uses only the first two and side imaging requires the highest frequencies. On the other side deep sea anglers need the 50kHz, so that the sonar beam will go deep enough for fishing big game species.