Down Imaging vs. Side Imaging: Which Technology is Better for You?

Some fish finders are equipped with a transducer that can emit a sonar that is much more powerful than your average sonar. Indeed, these powerful sonars are called down imaging sonar or side imaging sonar.

Those 2 types of sonars produce a very detailed image of the water and the objects in it, allowing the user to quickly and easily locate bands of fishes or spot objects in the water with greater accuracy than was possible before.

But if you have never used those sonars before, which type of sonar technology is the best for your need and when do you choose between a down imaging and a side imaging?

To answer this difficult and confusing question, we made this comprehensive comparison guide that will allow you to differentiate between down imaging and side imaging.

1. Down Imaging

As its name suggests, down imaging is a powerful sonar that provides a very detailed view of objects that are found immediately below your boat. It usually has an angle that does not exceed 22 degrees and even if this visual image is a little bit restricted, the clarity and amount of detail that it can output is quite amazing.

Additionally, the down imaging is an excellent sonar to use for those who usually fish in deep water with fishing lures like the jig. As this will allow you to see in real time the size of fish that your lure is attracting.


  • More affordable. A good quality side imaging sonar device will cost you around $1000. This is not cheap. On the other hand, down imaging starts around $300 which is significantly cheaper than side imaging. Best, down imaging generally has better clarity than side imaging and is also easier to understand.
  • Very detailed image. Since down imaging outputs a powerful sonar in a small angle, it has the ability to produce a very detailed sonar image. Especially when you carry it with a fish finder that has a high-quality color display. The amount of detail it can output is simply unparalleled, even more so when compared to the traditional fish finder that uses a regular sonar of lesser power.
  • Ability to adjust the angle. More fish finders equipped with down imaging technology has an angle adjustment that allows you to quickly and easily adjust the angle based on your need. The ability to adjust the angle, in turn, provides with a more detail imaging, as a smaller angle is able to concentrate the sonar power in a smaller area, thus giving you a more detailed image.
  • Ease of use. The transducer of the down imaging fish finder is usually flexible and all that is required to get an image is dropping the transducer in the water. Most of the time, there is no complex installations required with the down imaging system. Even better, the sonar image of down imaging is usually much simpler and easier to understand than side imaging.


  • Interference in deep water. Older models of fish finders that have down imaging technology have an interference problem when the sonar is used in water that is deeper than 40 feet. Although, this problem has mostly been resolved today and most modern models do a good job not producing any parasites in the imaging.
  • Affected by speed. Down imaging technology works best when the sonar bounces off the floor of the water or object inside the water and then returns to the transducer for calculation and imaging. If the boat is moving too fast, it can interfere with the fish finders’ ability to produce a clear image. This is not a problem with side imaging that is not affected by speed.

2. Side Imaging


Side imaging devices are fitted to the side of your boat and produce images that have a wide angle over long distances. This type of sonar was recently introduced by Hummingbird and has so far proven to be helpful to both amateur and professional fishermen.

One of the best things about the side imaging is that it has no problem delivering an accurate and clear sonar image even if the boat is moving at high speed.


  • Not affected by speed. You can attach your side imaging device to your boat and not worry about speed because side imaging is not affected by speed. It will still be able to produce a quality and detail image regardless of your speed.
  • Easy to mount. Most side imaging fish finders come with a mount that allows you to quickly and easily install your side imaging device to your boat.
  • Large angle coverage. One of the biggest advantages of side imaging is its angular coverage. Indeed, the image topography of side imaging can cover a wide angle and reach over great distances. This will provide you with detailed information about bands of fishes around your boat very quickly regardless of where the transducer of the side imaging device is pointed at.
  • Take snapshots and create waypoints. Most side imaging devices will allow you to quickly and easily take snapshots and save them on an SD card. Additionally, more advanced models have a GPS system which provides you with the possibility to mark a waypoint so you can easily find the location again later on.


  • It is expensive. Side imaging is a new technology introduced by Hummingbird a few years ago. However, unlike down imaging, side imaging is not cheap. Most of the time, a quality side imaging device starts around $1000.
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There are no clear winners when it comes to down imaging and side imaging. If you need a sonar image of fishes found below the boat, then the down imaging sonar is the best type of sonar to go with. Down imaging will produce a very detailed image even if the angle it can track is small.

On the other hand, the side imaging sonar sticks at the side of your boat and provide you with a visual image over great distances and even if the boat is moving. Even if side imaging is not as accurate and detailed as a down imaging, it will quickly and easily give you a general idea of where large bands of fishes are located.

Even better, you can use both down imaging and side imaging at the same time for maximum efficiency in locating fishes quickly and easily.

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