Interpreting sideimaging

Ive never owned one...but will soon. Of the dozens of photos ive seen of the humminbird sideimaging units I find myself confused on how to "look" at the screen. For instance, the black strip down the middle. I know this is water...but is that water on each side of the boat or under the boat? If thats water to the right and left of the boat then I should tilt my head to the left to see out to the right...and tilt to the right to see out to the left? Right? Wrong? And if thats the case....wouldnt it be better if the screen scrolled across rather than up and down?? Is the water closest to the boat on the outside edge of the screen or inside? Im really struggling trying to figure this out...and I cant find anywhere that explains it. I see plenty of talk about map cards..laptops, networking, PC cables, etc, etc...but never how to actually interpret the screen for a beginner. Maybe Im just too much of a beginner on this...but could someone fill me in?

From what I know. The black strip down the center is under the boat. Yes, tilt left to see right, etc. The images closest to you are from the black line under the boat and gets progressively further away the closer you move to the edge of the screen. Neck cramps are common from guys I have talked to learning to interpret the graph.

I am in agreement. They should have a button on the screen where you can flip the screen any direction you want. If you are scanning and looking primarily at the bank then you should be able to put that side of the boat on top and read it go horizontally. Only makes sense to me. I can flip the screen on my laptop any direction I want, why not the sidescan?

The Hound

The black strip is called the water column. Thats the time it takes for the ping to reach the bottom and return, you could call it the depth but it is going out to the sides too, remember the wave is an arc so if it hits some thing out there on the way down it returns a signal that'll show up in the dark area like trees, bait balls or large fish.
Copy an image and bring it into a photo shop program. There rotate the image 90° so the water column is at the top, then it'll look like the horizon. Now you should be easily able to visualize the up and downs.

WarrenMN

Ok...as I look at it...and i tilt my head left and look at the right side...am i looking out into the "horizon" and the farther away the bottom goes the farther away it is? And the black is the depth from top to bottom? They really need an instructional video on these things. I cant figure why they would have such a high dollar innovation and not have something to help us interpret it. Maybe the Humminbird guys here....and I know there are at least a couple....would care to comment on this?

Thats another thing that is keeping me from buying one although I love the concept. I have 3 or 4 spurs in my neck along with a metal plate with 4 screws in it to keep my head from falling off. And they want me to keep tilting my head back and forth? I don't think so. Yet

Cut out the black strip (water column), then slide the two sides together. That is what basically you are really looking at.

http://img.photobucket.com/albums/v6...Humminbird.jpg

So, I'm guessing it suppose to look like this right?

Spectrum...thats exactly how my mind is telling me to look at it. you hit it on the head. I could not explain it...but that is it. And if that is indeed how you do look at it...then the black strip down the middle is NOT the water under the boat...but rather the water looking out on the horizon from top to bottom. That bottom image where you turned it seems to me to be how the screen should scroll so we arent breaking our necks...if of course this is how we are supposed to look at it. Humminbird reps...still waiting for you to help. hint hint hint!

picture yourself standing in the middle of black water column on the bottom of the lake looking 90 degrees right and left as you walk forward. That's exactly what the sonar beam is doing as you are moving along.

Ok..then in that case the bottom closest to the black strip in closest to the boat? And then the bottom of the lake on the outside of the screen is farthest away? If that is the case then spectrums example of turing the page upright is incorrect?

I don't think this is the correct interpretation here. I might be wrong. I am old.

I think it should look like this.

Distance from left or right to an object in the water is distant minus width of water column (roughly).

For instance:

If the left and right margins are set at 100 feet and the water is 20 foot deep:

1. an object appears on the left side at near the 100 ft margin.
2. That object would be roughly 80 foot away to left of the boat.
3. 100 (setting) minus 20 (water column) equals approximate distance to object.

I have marked and measured waypoints relative to the boat, and this is how the measurements came out.

MHAO. I have been wrong before.

I'm not familiar at all with these units, only what I have seen and read here. My thinking and understanding was that the picture scrolls from the top towards the bottom of the screen. Also the black is the water under the boat and to the right is the view to the right and to the left is the view to the left. If you look at the shadow of the large rock looking thing on the left picture you will see why I say that, the shadow is away from the centerline or the boat. On the right side you can see nearest the boat the detail is brighter which is shallower and as you move away from there it darkens which mean it gets deeper. If you look at the sonar view you can see that you are over hump, a steep drop off to the right side and the begininging of one to the left. I believe on the screen there is a boat at the top edge in the center of the black that point upwards and this is a birds eye view, so to speak. So my deduction is that if the boat is pointing that way, to the right is the right starting straight down at the black and going all the way to horizontal as you look further to the right. The sonor is like a MRI scan taking shots of small slices of information and stacking them one behind the other thus putting together the picture we see. The last shot is at the top of the screen and moves downwards as it adds on, like a regular sonor that puts the last shot on the right side of the screen and moves to the left. As you look down the page that is what has already passed behind the boat. I hope I haven't confused the confused which includes myself. I'm hoping to get one in the future and am gathering info also. Im sure that a real pro will step up soon and make us all understand.
From the bayou,
PawPaw "gene"

Don't tilt your head. Imagine setting in your boat, in the dark and all the water is now gone from the lake. You shine a spotlight out each side of the boat, 90°. You can't see under the boat. That is the black line down the middle. You can see everything the light hits. Anything standing up throws a shadow.

Here is how I picture it. The light blue is where the light (transducer signal) can see. Dark blue is where it can't.

Again, don't tilt your head. It is kinda like having an ariel view of the lake bottom, with all the water gone.

http://i130.photobucket.com/albums/p...sidebeams1.jpg

I agree with Ranger 690's post above. I just imagine that i am above the boat looking down at a dry lakebed. Things that appear left of the boat are on the left, likewise right. Remember that like your regular sonar, things down screen are behind your current location. How far back depends on your boat speed and scroll speed.

Humminbird rep told me about the folding paper theory when I was a Grizzly jigs. This folded paper theory essentially removes the water column from the picture (except directly below the boat). Maybe the rep will post the folded paper theory here and you folks will understand what I am trying to convey.

Folded paper sure simplifies the mystery.

I found some of my si images. I will take a picture of the fold and post it. It is how Humminbird explains the images. Simple once you see the folded paper.

Pic before fold

http://i188.photobucket.com/albums/z...s/IMG_0513.jpg

Pic after fold. Notice the water column is below the boat and the sides of the image is pulled in the toward the boat the distant of the column.

http://i188.photobucket.com/albums/z...s/IMG_0517.jpg

http://i188.photobucket.com/albums/z...s/IMG_0516.jpg

http://i188.photobucket.com/albums/z...s/IMG_0515.jpg

http://i188.photobucket.com/albums/z...s/IMG_0514.jpg


Hope this helps.

Tom

Do not tilt head, very easy, you look at the screen your boat is located in the middle and top, see the little boat icon. the black area is direct under boat. Looking at the picture below you will see the letter A that is a log laying on the bottom. The edge of the screen is 60 each side of the boat. so the log is close to the edge of the screen so it probaly close to 50 from the boat to your left.

Also you notice the cursor it shows that it is 16 feet from direct under the boat.

When you see a white spot with shadows going away from you that is sonar shadow, longer the shadow taller the stump. Just think of like this if its on the left side of the screen it is to the left of the boat. move the cursor to it and it will tell you how far the stump is. Mark it and it will save a GPS point for your.

Attachment 15944

Thats excellent information guys. I am now starting to get the hang of it after your examples. I was just reading too much into it....tilting me head left and right....etc. Basically what you all have said is to just look at it as it is...like a bird looking down on a dry lake bed and looking left and right. This makes sense...and to be honest, the way I WAS looking at it would make a waypoint impossible to mark because I was imagining the water column as being a horizon out to the right and left (tilting my head). Its been one of those deals for me like one of those drawings that look like 6 little dolphins but then they tell you to look again and see if you can see the 2 people making love. LOL.

I'm with canepole, and if I'm not mistaken, so is the humminbird 797 manual. I'm pretty sure it explains this, but not using the paper method.

One quick question guys, and one funny story. Where is the boat in relation to the stump with curser at. is it already gone past the stump where the little boat symbol is, or is it actually directly beside the stump. After reading about the explanation of the water collum, i decided to ask the salesman at BPS who was trying to sell me a 997, what was the dark line down the middle. he said "oh thats the creek channel", i laughed and said man thats the straightest creek i have ever seen! lol.

The cursor is 16.8 feet behind the boats gps antenna, give or take a few feet for gps error.

I have posted this SI shot on several other forums. Some have said that it helped them understand how to interpret SI. Hope it helps..

The creek channel in this pic almost forms a box. There is very good detail of the fallen timber on the edge of the creek channel. (look in the creek for the "shadows" of the fallen timber)

Yes the "folded paper" exercise is exactly how you should think of the image.

http://i242.photobucket.com/albums/f...Pines008-3.jpg

Great Pic!! As im seeing it the creek actually made a bend and you crossed it twice. Correct?

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Originally Posted by CarpPoop

Great Pic!! As im seeing it you the creek actually made a bend and you crossed it twice. Correct?

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Exactly!..

Got it. The final thing im hazy about is the "water column" I hear this term alot for the black strip down the middle. Would this be the space under the boat that the side image beam doesnt cover since it shoots outward? But yet In this picture above, I see things in the water column...trees mainly. Can you elaborate on the "water column"? I've got the rest of it understood.

my understanding is that there is 2 beams on the transducer...the blue area is the actual side imaging beam that goes to the side and the black area is the other other beam which is directly under the boat and the beam that shoots directly down..

No, actually there are three beams, four if you count the lower freg thats used along with the 200kz vertical. The black line down the middle of the screen is the track of the boat. This will always be straight as the the sides are always perpendicular to the boat. Remember the side scan crystals in the transducer are tilted a bit so the inside part of the beam is about 6 degrees out from the center so it doesn't over lap the 200khz vertical cone. I borrowed Humminbirds diagram to show here. Notice the arc's out to each side. The distance from the transducer to where the arc first touches the bottom is the black area in the side scan, or the water column.
The deeper it is the wider the water column is.

WarrenMN

This is a diagram I did to show how the side scan sonar wave would travel out from the transducer to be reflected back. Look at each arch as the progression of a single ping.

WarrenMN

And that is why the folded paper scheme works. So say I and so say Humminbird.

You folks just don't believe me...ha

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Originally Posted by Cane Pole

And that is why the folded paper scheme works. So say I and so say Humminbird.

You folks just don't believe me...ha

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Ditto !

The more I read about these thing's, The more I've decided I don't need one,:D I'm so dumb I have a hard time just channing channels on my T.V. :p

Aw heck aint all that hard:)

Quote:

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Originally Posted by bentpole

The more I read about these thing's, The more I've decided I don't need one,:D I'm so dumb I have a hard time just channing channels on my T.V. :p

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Yea, I'd rather just see the picture like the 997's have on the "traditional" finders.;)

Quote:

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Originally Posted by bentpole

The more I read about these thing's, The more I've decided I don't need one,:D I'm so dumb I have a hard time just channing channels on my T.V. :p

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I wish I could come up with funny stuff like this. I love a good belly laugh! Its almost as good as catchin a big slab:D:D:D

yeah i hear ya....if you google sideimaging you will soon be lost in the world of map card, sd cards, interlinking, PC programs, PC transfers, PC upgrades, data transfer, hot maps, navionics gold, navionics platnum, no navionics at all, hi-def, multiple transducers, and on, and on, and on, and on. The yahoo group is loaded with alot of this advanced talk. I've said it before, its too bad there isnt a resource that starts at the beginner level where one can go and find the nuts and bolts rather than the advanced discussions. Its hard to even know what unit to buy and what accessories to buy with it. This site by far has provided the easiest way for me to at least get a clue about this stuff. But im still in the dark on most of it.

Quote:

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Originally Posted by CarpPoop

yeah i hear ya....if you google sideimaging you will soon be lost in the world of map card, sd cards, interlinking, PC programs, PC transfers, PC upgrades, data transfer, hot maps, navionics gold, navionics platnum, no navionics at all, hi-def, multiple transducers, and on, and on, and on, and on. The yahoo group is loaded with alot of this advanced talk. I've said it before, its too bad there isnt a resource that starts at the beginner level where one can go and find the nuts and bolts rather than the advanced discussions. Its hard to even know what unit to buy and what accessories to buy with it. This site by far has provided the easiest way for me to at least get a clue about this stuff. But im still in the dark on most of it.

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Don't ask the salesman at Gander Mountain in Jackson of the salesman at BPS in Memphis. They ain't got a clue. Be nice if those sales display units would do something besides show pictures. Buttons don't do anything. They prob got a display only ( idiot) program running so we can't mess with 'em.