SI interpretation 6/2

[slabbacks]

The shots that are being posted are intended to help new users as well as myself and others get the best image from their units. I ask that if you see a screen shot and have had a similar case, to post what have you have done to make it better or explain what you see as others have done on past post.

Please don't take these as a "I know it all" type post, that is not my intent. It's done to better help us both learn.
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These shots are posted to show how changes in Sen. and Contrast can make a large change in the image to better give detail to what we are going past. With the changes you can see better shadowing and crisper edges start to appear. One group of settings I find is not the best for all parts of the lake..it may show a picture but I find it could always be better with some fine tuning.





In the 2nd shot I take the bright cloud to the upper right of the temp as that bait cloud or group of fish moving away from the boat. Does this sound or look right?

[Humminbird_Greg]

I don’t know that you would be able to tell that the school of fish is moving in any certain direction, although in shallow water on a highly pressured lake they probably are moving away. Swim! It’s the hooks again!

Not to nitpick here but if you want to make a good comparison of what different menu settings do; make a sonar recording and pause it at a good point and make screen snapshots while you change the menu settings. Now the digital depth will be different as will the cursor data boxes but the same sonar image will be show and we will be able to see how the menu changes affect what we can see.

[kosmo]

I don’t know that you would be able to tell that the school of fish is moving in any certain direction, although in shallow water on a highly pressured lake they probably are moving away. Swim! It’s the hooks again!

Not to nitpick here but if you want to make a good comparison of what different menu settings do; make a sonar recording and pause it at a good point and make screen snapshots while you change the menu settings. Now the digital depth will be different as will the cursor data boxes but the same sonar image will be show and we will be able to see how the menu changes affect what we can see.

Greg,on my 998 I can can activate the cursor and that will pause the screen.then I can make adjustments,but with my onix I don't think that I can do that.i havn't made any recordings with the onix.can I make any adjustments from a recording?also,kool example slabbacbs,of how just a minor tweek makes a big difference

[rnvinc]

In the 2nd shot I take the bright cloud to the upper right of the temp as that bait cloud or group of fish moving away from the boat. Does this sound or look right?

I bet it is the same baitball that is to the right in the 1st shot...and the baitball is moving right to left in your boat wake behind you...
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What is deceiving in the 1st shot is that the baitball seems fairly "far to the right side" in the right dark water column of the SI image....

In reality...that baitball (in the 1st shot)...is closer to "directly under the xducer"....(and to the right just a smidge)..indicated by the faint echo return of the same baitball mirroring it in the left dark water column...

This means the baitball was close enough to the lower/outer fringes of the left SI beam to return "some" faint echo in the left SI dark water column...

The "deceiving" part is this scenario is that the main baitball echo (in the right SI dark water column)...is "painted" as "distance away from the the xducer"...not necessarily "distance to the right of the boat"...

So the baitball may "look" like it's ~12ft to the right of the boat...when the baitball is actually ~12ft under the boat and to right of center just a little...

12ft is 12ft ...to sonar....

It's the other clues in the image that give away the baitball's actual position in relation to the boat...

Clear as mud...??

Rickie

[rnvinc]

BTW slabbacks...great lesson in Sensitivity and Contrast....



Rickie

[slabbacks]

I don’t know that you would be able to tell that the school of fish is moving in any certain direction, although in shallow water on a highly pressured lake they probably are moving away. Swim! It’s the hooks again!

Not to nitpick here but if you want to make a good comparison of what different menu settings do; make a sonar recording and pause it at a good point and make screen snapshots while you change the menu settings. Now the digital depth will be different as will the cursor data boxes but the same sonar image will be show and we will be able to see how the menu changes affect what we can see.

Thx Greg, I was thinking they were moving away due to being under the boat (just to the right ) one pass then off to the left the next but more strung out. I can see how the recording being made and then working off one pass with different changes could help better. I'll work on doing this next time.

thx again

[slabbacks]

I bet it is the same baitball that is to the right in the 1st shot...and the baitball is moving right to left in your boat wake behind you...
_________
What is deceiving in the 1st shot is that the baitball seems fairly "far to the right side" in the right dark water column of the SI image....

In reality...that baitball (in the 1st shot)...is closer to "directly under the xducer"....(and to the right just a smidge)..indicated by the faint echo return of the same baitball mirroring it in the left dark water column...

This means the baitball was close enough to the lower/outer fringes of the left SI beam to return "some" faint echo in the left SI dark water column...

The "deceiving" part is this scenario is that the main baitball echo (in the right SI dark water column)...is "painted" as "distance away from the the xducer"...not necessarily "distance to the right of the boat"...

So the baitball may "look" like it's ~12ft to the right of the boat...when the baitball is actually ~12ft under the boat and to right of center just a little...

12ft is 12ft ...to sonar....

It's the other clues in the image that give away the baitball's actual position in relation to the boat...

Clear as mud...??

Rickie

Rickie, hoping to get the mud cleared up some on my part.

The shadows help me a lot on the bait cloud. If the shadow was farther to the right this would mean they were higher in the water column...right?? When I made my turn to come back around I turned to the right and moved back along the right side of my shot. Then made another pass. Those two passes may have pushed them that way.

Kosmo I'm just glad I was in open water and nothing to hit. This thing is addicting and you tend not to look up a lot!

[brettw]

Super SI

[rnvinc]

Rickie, hoping to get the mud cleared up some on my part.

The shadows help me a lot on the bait cloud. If the shadow was farther to the right this would mean they were higher in the water column...right?? When I made my turn to come back around I turned to the right and moved back along the right side of my shot. Then made another pass. Those two passes may have pushed them that way.

Correct....

The closer the shadow is to the target echo - the closer the target is to the bottom...

The farther the shadow is from the target echo - the higher the target is off the bottom...



Rickie

[Humminbird_Greg]

I don’t know about the ONIX kosmo as I haven’t had time to go out on the boat with one.

Wasn’t sure on the timing from one pass to the other for these images Rickie. I figured it was some time in between because I didn’t see any sign of aerated water near the zero centerline. You are correct about the baitball in the first image being under the boat. I missed picking up on them also showing in the left Si beam but I did notice what looks to be a shadow that they cast on the lake bottom. Sure indication that they were close to directly under but off to the right of the transducer. Not sure if I see any shadowing from them in the second image though. Maybe with some tweaking of the menus we could see a showdown more easily or not. That is why I like a sonar recording because you can take the same image and change it with menu settings while not having to watch where the boat is going or making multiple passes at a location – which could tip off other boats in the area.

With Si sonar: the shadow knows! [Wasn’t that a radio program?]