Down imaging vs. side imaging is a long-standing and confusing topic in fishing, but don’t worry, this article will break it down for you. Today we’re comparing these technologies side by side to help you decide which one is best for you so that you can make the best of your fish finder.
What is Down Imaging?
Down imaging, or downscan, is sonar technology that allows you to see directly beneath your boat. It’s able to give you a detailed image of what’s underneath your vessel, because unlike regular 2D sonar, a down scanner’s beam is narrower, and therefore more discerning in what it views.
2D scanners, because of their wide beams, sometimes take a little too much information in, so your returns can be muddled. Down imaging eliminates this problem. That said, down imaging returns and traditional, down-looking returns are oriented (and so function) identically.
Down imaging is especially useful for monitoring bait schools, or scouting debris, structure, hotspots, and fish hides. These fish finders are must-haves for anglers who prefer deeper waters.
Most down imaging fish finders rely on a single transducer.
What is Side Imaging?
Side imaging— sometimes referred to as Side Scan ( Lowrance) and SideVu (Garmin)— is a type of sonar that differentiates materials and textures to the sides of your boat. These scanners were first introduced to consumers consumer by Humminbird back in 2005.
Side imaging is excellent for viewing structures and locating fish, but its use is often misunderstood. Its real power lies in scanning large areas quickly— fish, debris, hides, and other objects included.
This is because sonar waves are projected far into the water on both sides of the boat with an expansive coverage across the bottom. A side scanner gives you a range of approximately 400 feet on both sides of your boat. If you’re a frequent angler, who needs a versatile scanner for both deep and shallow water, side imaging will serve you well.
Its only downside (if you’ll excuse the pun), is that there is a learning curve involved in using a side imaging fish finder efficiently.
Down Imaging vs. Side Imaging
Consider it this way: down imaging vs side imaging is a matter of pinpointing and depth or sweeping range. Technically speaking, neither is truly superior to the other.
What matters is your objective. Down imaging penetrates depth, vs side imaging sonar technologies which scan a wider range more rapidly, and provide a horizontal view underwater.
Still, which point of view is best for you and which one should you invest in? Let’s take a closer look.
What situations are Down Imaging best for?
As mentioned, down imaging is best for fishing in deep water— especially when monitoring bait schools and jigs directly beneath you. But it’s not limited to this.
Your down imaging fish finder also be used beyond fish finding, to locate objects like structure, vegetation, and debris. Down imaging sonars, like the Humminbird Helix, take excellent pictures of everything that’s beneath your vessel, not just fish.
What situations are Side Imaging best for?
Side imaging technology is best for anglers trolling through shallow bodies of water like creeks or bays. They function best moving in a straight line at speeds of 2 – 6 knots.
Although side imaging has picture-like quality, it is not affected by light or dark. This means that natural structures, objects in the water, and even bait fish are made clearly visible without silt or mud interfering with the scans.
Another great use for side imaging is mapping. Because it covers such an extensive range, you could easily mark hotspots you’d like to take note of or return to. Finally, side imaging is perfect for scanning large vicinities as quickly and efficiently as possible.
How do you use them together?
Both use a high frequency, razor-thin beam to achieve a higher level of detail than a 2d sonar. Side imaging fish finders generally have a larger proportional range when compared to down imaging sonar, while down imaging fish finders have the upper hand in depth.
Alternating between downscan and side imaging when trolling into shallow waters from deep water is extremely handy, and often necessary. But it’s tedious, isn’t it?
Not to worry. Manufacturers have the good sense to engineer fish finders that include both side and down imaging sonar. A good example of such is the Lowrance Hook Reveal 7 Tripleshot Fish Finder.
This is great because it means that you don’t have to purchase two separate devices or go through the hassle of setting up both and switching back and forth between them.
Even better news is that some fish finders enable simultaneous down imaging and side imaging with a split screen. You’ll get a complete 180 degree underwater view below your boat, optimization, for example, contour and color palettes in your menu.
How do you use these in combination with CHIRP sonar?
CHIRP fish finders transmit longer, more frequent waves than standard sonar, putting more energy into the water column. Advanced digital pattern matching and signal processing (pulse compression) allow CHIRP devices to receive and process dramatically more information from each pulse, enabling unprecedented resolution and target definition.
When used hand in hand with side imaging technology and down imaging, CHIRP gives anglers a much clearer picture of what’s happening underwater, and it will cover a wider range while scanning, helping you to see more fish than you would with a standard 2d sonar .
Using CHIRP in conjunction with down and side imaging is easy. Many devices have all of these functions built-in.
Is a Side Imaging Fish Finder worth it?
Side imaging is a highly useful tool that is definitely worth the money. While it may not be for every angler, side imaging has the advantage over down imaging thanks to efficiency. Side scanners cover large areas of water quickly and are extra-useful in locating find key spots, structure, baitfish, and targets. In short, side imaging offers way more visibility than down imaging and traditional 2D sonar.
It will take some practice to fully understand and use this tool to its full potential, but it’s worth the patience. Your fishing experience may not be complete if you’re missing a side scanner.
However, there’s no need for the down imaging vs. side imaging war, and you don’t have to pick one over the other. The best thing to do, no matter your fishing or trolling style, is to invest in— and make use of— both.
Final Thoughts on Down imaging vs Side Imaging
Down imaging vs. side imaging is a battle that has no winner. No one can say that either is better because they both have their purpose, pros, and cons— it all depends on you and what you need from your fish finder.
Either way, if you add one (or both) of these scanners to your tackle, you’ll find, catch and see fish more consistently.
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