Humminbird Helix 7 Si. How come the sonar and DI images dont match or show same thing. Chart speed is 3 for both. Sensitivity 16 for Di and I think 11 for Sonar
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Humminbird Helix 7 Si. How come the sonar and DI images dont match or show same thing. Chart speed is 3 for both. Sensitivity 16 for Di and I think 11 for Sonar
Sonar has a much wider beam than the DI. DI is a narrow slice while sonar is more cone shape so you are seeing a much larger area with the 2d.
Might try increasing your contrast on DI. It's under "DI Enhance". Roy is right that sonar can have a wider beam (depending on your frequency) than DI, but my interpretation of your sonar screen would have those returns closer to the middle of your sonar beam, which your DI should pick up. And of course the magic bullet, try restoring your defaults. Sometimes we change settings without even realizing.
I think I see a lot of small dots on DI, so i'd dial up stronger settings and maybe they'd show up then
Yeah, well maybe they ARE showing the same thing ... it's just that the fish in the DI image are small white dots. They may show up bigger if you had the zoom set at 20-30ft.
Personally, I wouldn't have thought the images in the 2d sonar side were "fish", to begin with .... looks more like brush, but that may just be me. :dono I would think that at 3.8mph that fish would have shown as an elongated arch. :scratchhead
I'll be using a Hook 7 this year, and doubt I will even have the 2d sonar screen turned on. I hear a lot of people say they like having the 2d & DI split screen on, so they can tell what the 2d screen is showing by what the DI image is showing. :yikes To my way of thinking, that's like needing/having an interpreter, when you already speak the language. :Doh:
That isn't brush in his 2d shot, definitely something wrong, I run split all the time. Depending on your style of fishing and your understanding of sonar beams shapes, there are very real advantages to running 2d and DI side by side.
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The 2d looks a little like the angle of the xdcr is slightly off. They're half arches, no?
I haven't ran Hbird in a while but that 2d sensitivity sounds pretty high from what I remember running my birds. Don't see any clutter but as somebody else mentioned I believe I would try restoring factory settings.
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They are fish. Sentivity on the 2D is 11. How do I restore system default?
Press Menu twice to get into the Main Menu System ...Quote:
Originally Posted by SwampCat
Cursor over to the Setup tab ...
Cursor down to Restore Defaults ...
Cursor right to activate ...
Rickie
2d is a cone so some of what you're seeing is in front of the unit while the di is flat and what you are seeing is in the rear view mirror? Depending on which unit you have the 2d cone may differ in size, hugely. 2d is often in 83/200 khz which means 60/20 degree beams but the di units seem to only have 2d in 200/455 khz which means 20/16 degree beams. The SI units seem to have 200/83 2d sonar, have di as well so why not the di? I'm considering some of these same issues so thanks for the post. What unit do you have?
(DI is a thin beam but at 75 degree angle so it's wider than the 60 degree 2d, way wider than the 20 degree 2d)
Another thing to consider is that in the cone shaped 2d format the object is getting pinged multiple times as it moves through the wider cone while in the thin fan shaped DI mode the object gets far fewer pings so the image may not display with the same bulk.
I’m having the exact same issue? If you get it worked out please let me know.
So let's make some distinctions here ...
The OP lists his unit as HELIX 7 SI ...
The only HB SI units that have a dedicated "down pointing" DI piezo are SOLIX, ONIX, and MEGA 9, 10, and 12 ...
All other HB SI units derive the DI view data from the "side pointing" SI piezoes ...
This basically means that any targets directly under the xducer are residing in the outer fringes (less sound strength) of the SI beam sound pulse ...
Simply put - less sound strength area = less echo reflected = less echo data to display in the SI unit DI view ...
Here is the beam form for the right SI pulse showing the Main Axis (strongest part) of the right SI sound pulse ...
Attachment 288544
Mirror the above depiction for the left SI sound pulse and realize than any targets under the boat are just not reflecting as much of the SI sound pulse from that area under the xducer ... Therefore, not as much echo data to display in the HB SI unit DI view ...
Rickie
I've seen some of your comments on GON, you da man. I got a question related to this but I don't want to mess up his thread so I'm posting it. This stuff is like a onion, it just keeps going, just depends on how many layers you need to peal off.
well i just learned something new from Rickie's post.......the 30deg (roughly) angle that side imaging shoots at is from the horizontal top, or water surface. For a couple years now i always thought it was 30deg from horizontal bottom.
Ive experimented with tilting down imaging transducers to the side, but never went past 45deg off horiz bottom thinking surely it wouldnt work :dono
This makes sense. On the DI half of the screen - I get some great images of brushpiles that don't show upon the 2D sonar, also.Quote:
Originally Posted by rnvinc
Thus is because that brushpile showing in your DI view (in the HB SI unit) can be in the SI piezo beam form outside of the 2d cone ...Quote:
Originally Posted by SwampCat
Rickie
The SI beam form is measured horizontal from SI xducer ...Quote:
Originally Posted by Schins
One can see the 30° angle of the SI piezoes in this cutaway ...
Attachment 288562
No DI piezo pointing down ...
Rickie