EchoMap Plus 95sv - TVG setting

[SonarSentinel]

Generally speaking, how does changing the TVG setting affect my 2D sonar display? I read the book notes, but don't really understand how this affects the display output.

Edit - I should add I am trying to fine tune my 2D display. Trying to decide if/how I would deviate from default settings. Also the power/gain setting - is there a consensus - auto or manual setting? I also prefer to leave my display in night mode, which causes the 2D screen to be dark.

Is there is a thread for the EM+ series, that shows screen shots and associated fine tuning settings please paste. Thanks again folks.

Thanks,
SonarSentinel

[SonarSentinel]

No takers? Someone must know - how changing the TVG setting affects the 2D sonar display. I tried all four settings and I don't see any noticeable difference; except a wee bit less surface noise on the very top of the screen. I'd like to know in a more plain English way, what this variable does.

[DYE]

It depends on how you want to use your 2D sonar. If you are looking for fish you're trying to catch, turning up the TVG will filter out the smaller fish that are in deeper water making it easier to spot the fish you're looking for. On the other hand, if you're searching for baitfish, then you'd want to turn TVG down or off. Because of the way sonar works, fish that are closer to the transducer can appear larger than they actually are because they produce a stronger return, and TVG tries to compensate for this by applying a multiplier based on depth.

[LWINCHESTER2]

The way that TVG is explained as a concept and how it is implemented seem to me to be different on Garmins. It is explained as applying more gain at deeper depths and on a relative basis this is true. It looks to me that the way Garmin implements it is that the gain is wherever you set it, then TVG reduces the gain at shallower depths. The result is that deeper water gets more gain than shallow water but it is by reducing the gain at shallow depths instead of applying more at deeper depths. My point is that if you want more gain at the deeper depths, you'll need to add it yourself. Adjusting TVG won't do it.

[SonarSentinel]

Thanks guys, that actually helps.