Crappie reeper.im like you and others.i dont fully understand all of what richard says.i just imterpit it the best that i can.
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Crappie reeper.im like you and others.i dont fully understand all of what richard says.i just imterpit it the best that i can.
i have a hard time getting any fishing in, just for playing with the buttoms lolQuote:
Originally Posted by Cane Pole
:cool:i should of known better,but i kept on playing with those new units at gander mountain.i bought a new998. i bet my wifes not going to like this. oh well. heres some pictures in the simulator mold,the map on the unit shows it to be lake lanier, ga. i bought it at universal mania.i dont think that you can beat there price.
If you use 2d you won't even know what you are looking at, not to mention the false positives you'll get. You could stop directly over a thick hedge or some other gnarly and not even know what you are looking at with 2d let alone if there is actually any fish on it. DI shows you without a doubt. If 2d is the best, why would anyone buy a DI unit? It sounds like HB wasted a bunch of time and money coming out with 900 series DI units.
I'm certain not many will buy a $2200 DI unit and only use the 2d.
I'm saying in general terms that 2d cannot show you 20% of what DI can. I don't care what brand it is.
Please realize that I am in no way a sonar expert.....so a lot of what Rickard says goes way over my head....
I do know that Tom is correct when he says that ...."Sonar is nothing but a time domain reflectometer that uses water as a transporter median".
That basically means that sonar knows nothing but time...it does not know distance nor placement of small ping reflections (fish)....
I do understand the concept in the graphs below...
Attachment 71863Attachment 71864
It means that returns from fish out to the sides are displayed in a position on the DI screen that (in some instances) can be misleading to most fisherman....Now, I am sure that "some" fish returns that show up under the boat on the DI screen are, in fact, under the boat...but that does not make it conclusive that "All" returns showing up under the boat on the DI screen are, in fact, under the boat....
The only known is the time it took for that return to come back from that reflector (the fish)...so a fish out 50ft to the side can be shown as 50ft under the boat....because 50ft is 50ft...in time span of sonar pinging...
I have read that very thread 10-20 times trying to garner what this means to me as a fisherman....and this is what I can gather....(and I still may be wrong in Rickard's interpretation)...
In DI from SI crystals (797, 798, 898, 997, 998, 1197, 1198) there is no way to tell in a DI view if the fish showing at "X" depth is actually at "X" depth under my boat or if the fish is "X" distance to the side of my boat...
In "True DI" (DI with dedicated crystals).. a person can discern if a fish showing at "X" depth on the DI screen under the boat is , in fact, (somewhere ) under the boat by using the 2d in conjunction with the DI...if the fish at "X" depth shows up in the DI AND the 2d...then that fish is very well under the boat somewhere where that fish is reflecting from the DI sonar beam shape AND the 2d sonar beam shape...
If that fish at "X" shows up ONLY on the DI..then that fish is "somewhere" outside of the 2/d sonar beam shape....left or right...."X" distance away from the transducer but unknown as to where in the water column....
So a fisherman that owns a unit that has DI from the SI crystals cannot discern where in the water column that fish reflection came from (in the DI view)....
Conversely, a fisherman that owns a unit with "True DI" can only discern approximately where a fish reflection came from in the water column by using the DI "in conjunction" with the 2/d...but still the fisherman cannot determine if that fish reflection came from left or right of the structure that "it looks like" that fish is sitting on....
What all this jargon means to me as a simple minded crappie fisherman is....
I should look for structure...not fish.... (especially when using DI)...
I feel that 2/d shows the fish return the most accurately because of the cone shaped beam...if that return is not attached to the bottom and it reflects sonar..then that reflection is definately a fish (or floating debri the same reflective capability of a fish)...in that cone shaped beam which is directly under my xducer...
SI can determine which side of the boat a fish reflection is..and also determine the approximate depth of the fish by taking into considration where the "shadow" from that fish reflection is cast onto the lake floor out past the fish reflection.....
DI makes pretty pictures to post in forums but the information that is actually shown on that DI screen is too limited (and unknown) to discern "where" that fish reflection is coming from...
Just like Fishton asks in that thread...when looking at a fish return on the DI view...how does the fisherman know whether to use a jig at "X" depth under the boat...or use a surface popper at "X" distance out to the sides of the boat...I'm afraid DI is not the best tool to be targeting fish returns.....structure returns..yes...but fish returns...no...
Now, I hope that everyone that has went out and bought a "True DI" unit (either brand) doesn't feel they made a bad choice....
After all....I still feel that sonar should be used to find structure...not fish...find the structure (in the fish's confort zone)..and the fish should be there....
Rickie
DohDohDohDohDohDoh The more I read about these things, the more I realize what "I DON"T KNOW":confused:
Im just kinda asking here. Hope this makes sense.
Is it possible that fish, or structure can show up on DI that would not show up on traditional sonar.(I am not talking about sidescan) Due to the fact that DI beam is wider and reaches out slightly beyond the width of the boat. If an object was just barely in the edge of the DI it would show up on the DI screen.? Then it would not show on the 2D correct? If the object shows up on both screens isn't it a pretty good assumption that it is practically under the boat.
Don't crucify me guys. I'm just asking. I am not trying to give any information. Lord knows I am not qualified for that.
Sorry RNVINC you must of been posting while i was typing. You pretty much confirmed what i was mulling around in my head.
2d and di don't know what side the boat objects are on. Only SI knows this.. I have 2 units up front. 2d, di on one. si, maps on the other. When it is working right that is to say. Best of all underwater worlds.