Humminbird Side Imaging Forums

Side Imaging Forums => 997c SI, 998c SI & 999ci HD SI => Topic started by: sgtstout on June 17, 2010, 11:06:37 PM

Title: Beam width setting for 2D and SI
Post by: sgtstout on June 17, 2010, 11:06:37 PM

I have searched the forums up and down and can't find anything on the questions to follow...

1. What is the ideal beam width setting on the 2d and why?
2. What is the ideal beam width setting on the SI and why?

I have changed them around and don't really notice a difference. Any help would be greatly appreciated.

Thanks,
Brad

Title: Re: Beam width setting for 2D and SI
Post by: RGecy on June 17, 2010, 11:30:24 PM

Brad,

Not sure about question 1.  2d does not have a beam width to adjust.  I think you are refering to DI or Down Imaging.

In that case I would say that wide will offer you the best images for objects or fish in the water column.  If you are looking for more detail of structure on the bottom, narrow works better.  And of course, med is in between.

As for SI, the optimum range with 800khz is 2 to 3 times your depth.  This is because the beam in 800khz is smaller in the vertical than the 455khz and does not give you the full 180 deg coverage.  In 455khz I would recommend 3 times your depth depending on your depth.  You typically would not want a range of 150' in 10' of water if you are trying to spot fish.  Maybe if you are looking for large structure yes.

Basically, you want to keep the range as low as possible without sacrificing too much area to the water column.  But the larger the range, the smaller objects will appear on the screen.

Hope that helps a little,

Robert