Understanding Range ?

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Bryanmc57 &raquo;</td></tr><tr><td class="quote">I'm glad you understand now because what you just wrote confused the crap out of me again (still) http://www.bassboatcentral.com/smileys/roll.gif http://www.bassboatcentral.com/smileys/roll.gif http://www.bassboatcentral.com/smileys/roll.gif </td></tr></table>

LOL He got a little excited there LOL.

721. If your in 100ft of water and have the beams out to 125ft and you see a fish on the edge of the screen on the bottom. You can pitch your spoon 25ft and be directly over the fish but you will need to let out allottaaaa line to get to the fish cause she is 125ft + deep

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by T Mike &raquo;</td></tr><tr><td class="quote">
721. If your in 100ft of water and have the beams out to 125ft and you see a fish on the edge of the screen on the bottom. You can pitch your spoon 25ft and be directly over the fish but you will need to let out allottaaaa line to get to the fish cause she is 125ft + deep </td></tr></table>

http://www.bassboatcentral.com/boardstuff2/beers.gif http://www.bassboatcentral.com/boardstuff2/beers.gif http://www.bassboatcentral.com/boardstuff2/beers.gif http://www.bassboatcentral.com/boardstuff2/beers.gif
I agree 100%

On the screen you see 100% of the scale you have, Starting under the boat. The distance isn't from the center of the boat out to the side, it is the distance from the transducer to the object.


721 ProXP

the easiest way i learned how to range with my unit was,i idled past my dock at different distances and checked it on my screen to make sure what i was seeing.it really helped shorten the learning curve. http://www.bassboatcentral.com/smileys/thumbsup2.gif
once i did this then i ventured out to open water and started searching and by doing the previous i was able to look at creek chanels and such and the interpretation was simple.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by T Mike &raquo;</td></tr><tr><td class="quote">Maybe this image will clarify all doubt. The cursor show 22.2ft and it's in the water column? If the range started at where the bottom starts the cursor would show 0ft until it got to where the bottom starts.

http://i123.photobucket.com/albums/o...nar/cursor.jpg</td></tr></table>


Well, I thought I had it. According to this one Mike, you say the area represented by the blue "bottom" starts 69.5 ft (134 range - 64.5 depth) out from the transducer and shows from there out to the side to 134 ft.

BUT

In another post you said this, which sounds like the opposite to me:
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by T Mike &raquo;</td></tr><tr><td class="quote">If your in 100ft of water and have the beams out to 125ft and you see a fish on the edge of the screen on the bottom. You can pitch your spoon 25ft and be directly over the fish but you will need to let out allottaaaa line to get to the fish cause she is 125ft + deep </td></tr></table>

Which sounds like you're saying where the water column and bottom meet is directly under the transducer and you get the balance of your range out from there.

I may just be having a dense moment and not understanding.....

According to Doug's video (when he folds the paper) the water column is directly under the boat and should not be considered part of the distance in the side image range.

This seems to be confirmed when driving directly over structure and equal parts of it show up on each side.


Modified by mikeky at 10:19 AM 1/2/2011

I agree. The water column is the water directly below the boat. The shallower the water, the narrower the column. The deeper the water, the wider the column. This isn't so evident in pics taken in deep water, but is quite clear in shallow water pics.

PLUS, when you drive directly over a stump or fallen tree and it shows up on the outside of both water columns, this tells me the water column is, in fact, ONLY the water directly below the boat. That part of the image that starts at the edge of the water column and runs out to the far edge of your 100' range setting (for example) describes the bottom from below the boat out to 100' to either side.

http://www.bbcboards.net/zerot...58458

If you are only 50' from the shoreline and have your range set for 75', your image will show roughly 50' of bottom on either side and blank out the remaining 25' on the far edge of the screen.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by mikeky &raquo;</td></tr><tr><td class="quote">According to Doug's video (when he folds the paper) the water column is directly under the boat and should not be considered part of the distance in the side image range.</td></tr></table>

BUT...
If that's the case then, say you're in 100 ft of water with the range set at 200. The water column will take up 50% of the screen on each side. Are you saying that the graph compresses 200 ft of side image (the part that isn't shown as water column) into the remaining 50% on each side? That doesn't seem correct either.

Doesn't matter how deep the water is. Deep water just means a wider water column. The range itself starts at the edge of the water column and runs out each side to whatever distance you have the range set.

Besides, who fishes in 100' of water? http://www.bassboatcentral.com/smileys/eek.gif http://www.bassboatcentral.com/smileys/popcorn.gif

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by BrownTrout &raquo;</td></tr><tr><td class="quote">Doesn't matter how deep the water is. Deep water just means a wider water column. The range itself starts at the edge of the water column and runs out each side to whatever distance you have the range set.
Besides, who fishes in 100' of water? </td></tr></table>

You'd be surprised.... Here you can be in 100 and casting into 45 in a lot of places

So you're saying that in this image, the arrow that says 134 ft should be adjusted so the right tip is at the edge of the blue, not at the centerline? Seems the two pro-staffers (Doug and Mike) have opposing ideas LOL l

http://i123.photobucket.com/albums/o...nar/cursor.jpg

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Bryanmc57 &raquo;</td></tr><tr><td class="quote">

You'd be surprised.... Here you can be in 100 and casting into 45 in a lot of places

So you're saying that in this image, the arrow that says 134 ft should be adjusted so the right tip is at the edge of the blue, not at the centerline? Seems the two pro-staffers (Doug and Mike) have opposing ideas LOL l

http://i123.photobucket.com/albums/o...nar/cursor.jpg</td></tr></table>

In this picture the bottoms on each side are pretty much a mirror image. I don't think this would be the case if they were 130' apart.

Like in the picture above the 64.5 ft line is the distance to the bottom, It is also right under the boat. So if you move the cursor out to the bottom it is going to show 64.5 ft. This isn't out to the side of the boat but the range from the transducer to the bottom.

10 Ft out to the side of the boat will show around 75 ft not 10 Ft.

721 ProXP

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by mikeky &raquo;</td></tr><tr><td class="quote">
In this picture the bottoms on each side are pretty much a mirror image. I don't think this would be the case if they were 130' apart.</td></tr></table>

I don't think they are either.

The question is... is the blue area on either side:

A. 134 ft wide
B. An area from 134 ft to the side of the boat IN to 69.5 feet from the transducer
OR
C. An area from 64.5 ft from the transducer out to 134 ft from the transducer.

I've seen all 3 answers in this thread.

Now my head hurts http://www.bassboatcentral.com/smileys/roll.gif http://www.bassboatcentral.com/smileys/roll.gif

As I mentioned before. Play a recording with HumViewer and watch the digital range as you move the pointer across the image when you stop the playback.
The range does not change until the pointer gets to the bottom of the water column, there it starts at zero and increases as you move the pointer to the outside edge of the image.
The data that HumViewer uses is the same data the Side Imaging unit uses and doesn't act like what is being described here for range/distance.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by 721 Pro XP &raquo;</td></tr><tr><td class="quote">Like in the picture above the 64.5 ft line is the distance to the bottom, It is also right under the boat. So if you move the cursor out to the bottom it is going to show 64.5 ft. This isn't out to the side of the boat but the range from the transducer to the bottom.

10 Ft out to the side of the boat will show around 75 ft not 10 Ft.

721 ProXP</td></tr></table>

Bingo!!!!!! Thats how i understand it.

Well, let's see. I thought I understood this until I read all the posts on this thread and now I'm totally confused http://www.bassboatcentral.com/smileys/Laugh.gif

Judging from the 3rd image in the following link, the 2D down image shows roughly ~8' of bottom if he's using the 200kHz transducer and that image captures much of the DI and SI image detail so the water column must be larger than what's shown in this 2D down image. So, maybe the water column is equal to the depth of ~26'.

http://www.bbcboards.net/zerothread?id=616542

The question then is where does the image start and end for the selected range. It looks to me like Mike is right. The range starts with the area immediately below the boat and runs out to the end of the range setting of 100'. The water column component of the range is ~ 26' with and the remaining area is ~ 74' to each side.

Clear as mud?

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by BrownTrout &raquo;</td></tr><tr><td class="quote">

The question then is where does the image start and end for the selected range. It looks to me like Mike is right. The range starts with the area immediately below the boat and runs out to the end of the range setting of 100'. The water column component of the range is ~ 26' with and the remaining area is ~ 74' to each side.

Clear as mud?

</td></tr></table>

You got it!! The cursor is your friend here if you need more precise info as it is telling you distance from the ducer, but honestly I don't use it to figure out distance but only to mark waypoints off the side of the boat. Technically the only variable you have once you get out of the dark blue is depth as you can improvise distance by sectioning off the screen based on what the range is. But if your lucky and your object or fish is close your DI or a SI shadow might get you an idea as well. That's why 3 way is a powerful tool for the vertical angler to help tie everything in.

DI isn't as useful but if something is just out of sonar range but in DI I know it's relatively close. If it's out of DI range but in SI I know it's a little farther out. Depth also plays a factor here and how deep the object is. Thats why it's important to know the layout of all your beams. A lot of times in spoon fishing you get fly buys of small schools of fish. You get one shot and only one shot a lot of times. So you gotta process this info fast and be somewhat accurate in hopes of getting bit.

You can really write a book on this stuff. There are so many variables and situations it's hard to cover them all. But it's fun as hell when it works out.

Fishing in 100ft of water isn't too common around here but it does come up occasionally. I don't fish on the bottom but most of our fish suspend around 30 to 60ft deep over a 100ft bottom. Going off memory the deepest I have gotten a spotted bass was like 105ft.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by BrownTrout &raquo;</td></tr><tr><td class="quote"> The range starts with the area immediately below the boat and runs out to the end of the range setting of 100'. The water column component of the range is ~ 26' with and the remaining area is ~ 74' to each side.</td></tr></table>

Right, The image starts under the boat, The water column will be from the transducer to the bottom. The image doesn't run straight out from there to 100 Ft, It is from the transducer out 100 ft. So in Zero water it would run out 100 Ft. but in 50 ft of water it will only run out 60 to 70 ft to the side of the boat. In 90 ft of water it would only shot out 20 to 30 ft from the side of the boat.

It forms a triangle. The down line is the depth,26 ft, then you have the base line X, and the 100 ft line that goes from the end of X back up to the boat.

so 26 square + X square = 100 Square

This will give you the distance out that is acually painted on the graph.
Stand on the roof to your house with a 150 ft rope and see how far out in the yard it will go. Now look at it from other roofs at different heights. The rope is always 150f t yet it won't always go the same distance in the yards, and it won't go out 150 ft ever!!!!

721 ProXP


Modified by 721 Pro XP at 6:51 PM 1/2/2011

What if you have bottom range set at 100 ft and your in 100 feet of water and your side imaging is set for a 100 ft then are just going to see a water column?

I don't think bottom range applies to SI. I think it only applies to DI and 2D. But if you're in 100ft with SI set to 100ft, pretty much all you'll see is water column.

The rope is always 150f t yet it won't always go the same distance in the yards, and it won't go out 150 ft ever!!!!


If the rope is parallel with the ground it will be 150' out