The Hull Truth - Boating and Fishing Forum - View Single Post - Thom...right again!
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Old 07-19-2004, 02:21 PM
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Default RE: Thom...right again!

Actually as I recall my original comment (and my ability to recall anything at all is slipping fast) it was really in response to something someone else had said. I didn't think I explained what I was trying to say very clearly then, and might not now either, but let me try it again.

Let's say that you are out there in 200 feet of water and you have a Garmin 240 and a Garmin 160 looking for fish. Let's also say that there are a couple of small fish down there, off the bottom in open water.

The Garmin 240 has a vertical pixel count of 240 and the model 160 has a vertical count of 160, no suprise there. If we took our 200 feet of depth and divided it by 240 we'd find that each pixel would be able to represent just slightly less than 10 inches of the water column. A Garmin 160, with its fewer pixels, in the same water would have each pixel able to represent about 15 inches of water.

The post I was responding to, as I recall it, said that the fellow didn't think that either fishfinder would show a fish that was less than 10 inches tall and that the 160 wouldn't show a fish that was any less than 15 inches tall. Well, that's just not true. As long as the fish was capable of giving a sound reflection the machine was capable of displaying each of them would have lit up one pixel, its just that the 240, with its smaller dots on the screen would have shown a more distinct image than its blockier little sister. Where the real question comes up is what happens if you have a school of small fish, a bait pod if you like, and you were looking at it from each machine. The machine with the finer resolution may be able to distinguish individual fish whereas the machine with the coarser resolution might just show one big blob of a return. Well, is it really important? Not to me it isn't, but if I were a reef fisherman in south Florida trying to distinguish between a good Grooper and a couple of small bait fish swarming around it sure would matter to me.

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