When you mark a fish with downvision, are you marking the skull or air bladder ? Please solve this friendly argument for us . Thanks --p.s. I assume downvision works the same for all brands, correct ?
When you mark a fish with downvision, are you marking the skull or air bladder ? Please solve this friendly argument for us . Thanks --p.s. I assume downvision works the same for all brands, correct ?
I believe the correct answer is air bladder.
Works the same for all - AIR BLADDER
After thinking about it, my answer isn’t quite right.
Sonar - is seeing the air bladder - the “red arch”
DownVision is a Narrow x Wide beam that’s more of an “MRI like” scan. It’s the “picture view” so it’s not really picking up the image the same as sonar, which I believe is the root of your original question.
Then how do we some imaging pics with detail of the fish?
DownVision is an image scan for lack of a better term. Not sure I follow what you’re asking
I would think downvision scans the whole fish and produces the image.
Regular sonar sees both air bladder and skull hardness. Pics of big catfish on reg sonar show the stronger signal off its head.
More info needed !--Am I missing something ? When I split screen -sonar & downvision- I see the red arches of a sort for fish. On the the down vision I see a white spot a fraction of the size of the sonar . I thought that white spot was either the skull or air bladder. Should I be seeing the whole fish with down vision ? Am I missing something ?
remember that the fish could be angled and/or moving, so when its scanned it wont always look like a normal fish shape.
Think of putting a small toy fish at different angles under a paper scanner/copier. Unless its laid on its side perfectly, the image wont look like a fish shape.
Chief Brody hit it. I don’t think the exact correlation you are looking for exists.
This picture explains sonar. DownVision again is a picture view. Take pictures of objects from all angles - they are all different.
At at the end of the day, you are lookin for red arches (sonar) and “tic-tacs” (DownVision).
Chief Brody hit it. I don’t think the exact correlation you are looking for exists.
This picture explains sonar. DownVision again is a picture view. Take pictures of objects from all angles - they are all different.
At at the end of the day, you are lookin for red arches (sonar) and “tic-tacs” (DownVision).
All sonar shows you the map of the reflections of sound waves off of the fish. The stronger the difference in density, hardness, etc., the stronger the reflection. The interface between air/water (swim bladder) is strong, but other parts of the fish reflect at least some sound. The regular sonar scans a wider "cone" - so as the boat passes over the fish, at the edges the signal is weaker and further from the boat, in the middle it is stronger and closer. This makes the arch. The imaging beam is more narrow so you don't get the change in distance, and because you're scanning a narrower area of water you can see smaller details which are covered up by the traditional cone's "averaged" output.Originally Posted by Jig34
I stayed out of this thinking this thru But Matt I Believe is correct.
The traditional sonar and Side/Down Vision uses SONAR, the "Sonar" is one cone in either 50/200, where the Side/Down vision is like a knife edge slice sonar.
One other thing to consider is the processor and how it interprets the returns and shows them. The Side/Downvision isn't a different technology like a CT or MRI machine, imaging the bottom and structure its still sonar. So if a fish is swimming at you as you pass over it it might only be in the Downvision a fraction of the time verse going thru the cone. Shine a flash light and watch something go thru it or move it over an object, then take a pin light and do the same thing.
This is why I use the Side/Down Vision to look for structure/contour changes and not so much for trying to spot the fish. I mark the structure or what part I think most likely will hold the fish and go back over it with the sonar.
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