Mega di/si concern

[Jhawknseattle]

I’ve owned my units for about a year and have caught many fish because of them. However one thing that continues to irk me that I can’t seem to figure out is why the fish detail is so low on mega imaging. My smallmouth are deep right 9 months out of the year like more than 30 feet. Right now they 40-100 feet. No matter how much I play with the down image settings, I cannot replicate the ability to mark fish like I can with the 455 frequency. Here’s an example. I was marking perch in 73 feet of water. Clear as day on the 2d and 455. I kept going over the same spot at the same speed with the mega frequency and it looks like a ghost town. What am I doing wrong??

I am aware that the mega has its depth limitations but I was experiencing the same thing at 30 feet in the summer. I like the structure detail of the mega frequencies, but find myself not using it because I can’t see fish.

[Wayne P.]

You are doing nothing wrong except not understanding the frequencies and their coverages.
The MEGA frequency produces a thinner sonar pulse and higher detailed images.
You get a more blurry image with 455 kHz with the wider sonar pulses so fish are displayed larger.

[OK_BassBum]

Which also means those small dot's you are seeing on DI are fish.

[Jhawknseattle]

So then what’s the point of the mega frequency? Sure I can see rocks and trees with more detail, but if I can’t identify suspended fish? I just don’t understand what the point is. I’m glad to see I’m not doing anything wrong, but if I have to choose between a blurrier image that honestly is still pretty good where I can identify perch at 70 feet easily, or a clear picture where I can’t see bass at 30, that’s an easy choice. Thank you for your response, it’s been really bugging me winter fishing lol

[OK_BassBum]

Dialing in the SI & DI is essential. It took me awhile to learn how to get clear pics.
These are small mouths in the brush at Bull Shoals. 22.5 ftow

[bobcoy]

Sometimes good old 2D is still the best way to see fish. Each type and frequency has its advantages at different times and fishing tactics. I think all 3 are 1 piece to a puzzle. Whether you are looking for structure or fish each has its own uses. Split screens are a blessing. I almost always have 2d combined with an imaging screen. Learn how to use them all. JMO Bob

[SLYDoggie]

I troll so I'm not interested in structure. I find that 455Khz is definitely better at all depths for showing fish in the water column. I don't even bother with Mega for finding fish. Mega is great for identifying fish in structure, like the picture OK Bass Bum posted, and works best in 35 ft water and shallower. Mega works deeper but you definitely have to tweak the Sensitivity, Contrast, and maybe even Dynamic Contrast settings as the depth increases.

I also agree that you need all imaging technologies to put the full picture together. There is nothing better to identify potential fish than with the 2D arches. In my typical setup on one of my graphs, I have 2D at the top right 25% and DI at the bottom right 25% of the screen. When I see arches on 2D, I then look at my DI image right below it to see the detail and determine what is really there. It's great to have one above the other as they exactly match and it's very easy to compare the two images.

[Wayne P.]

Mix of shad, crappie, and bass.

[bobcoy]

Great shot Wayne! If the OP looks closely at the DI it matches up with the fish ID symbols, but you have to look very closely on the DI. The Fish ID is another feature many discount as valuable. They are wrong. This is a great feature which highlights what are most important, adult fish. JMO Bob

[SLYDoggie]

Great shot Wayne! If the OP looks closely at the DI it matches up with the fish ID symbols, but you have to look very closely on the DI. The Fish ID is another feature many discount as valuable. They are wrong. This is a great feature which highlights what are most important, adult fish. JMO Bob

When I use Fish ID, I do the same as Wayne... only the depth and not the symbols. It's a good way to quickly determine depth with just a quick glance while trolling.

[SLYDoggie]

Here are a few pics with DI below 2D, as I mentioned above, using Mega and in one of them you could clearly see the fish down to 60'. You just have to have Mega dialed in to do this. Also, I use Water Column Sensitivity set to +3 which helps the fish stand out.

[bobcoy]

Both are important to me, either relatively shallow and open water fish. With 100 + feet of water displayed it is easier to determine exact depth. Is there a way of displaying depth without the fish symbols? I also use the fish sizes to help determine species. It is easy to pick out the Bass and Walleye from the stripers (which I don't want to catch) We don't have many hybrids, but the symbols would be less than the biggest symbol same as the Walleye. I have found the symbol sizes to be a good indicators of fish size. Bob

[Wayne P.]

Both are important to me, either relatively shallow and open water fish. With 100 + feet of water displayed it is easier to determine exact depth. Is there a way of displaying depth without the fish symbols? I also use the fish sizes to help determine species. It is easy to pick out the Bass and Walleye from the stripers (which I don't want to catch) We don't have many hybrids, but the symbols would be less than the biggest symbol same as the Walleye. I have found the symbol sizes to be a good indicators of fish size. Bob

SOLIX/APEX units can display the depth without the fish symbols. You get both with Helix units.

[bobcoy]

Doh! I never saw that. It can sometimes get a bit cluttered. I will have to see if I like it or not. Thanks Wayne.

[bobcoy]

I guess you can't teach an old dog new tricks! I miss the fish and the info I had before(size reference). Size matters to me. Bob

[Jhawknseattle]

Those screen shots are phenomenal. I’ve played around with contrast and sensitivity a lot and get no where near that. I’m not familiar with other settings like water column sensitivity so maybe those types of things will help

[SLYDoggie]

I guess you can't teach an old dog new tricks! I miss the fish and the info I had before(size reference). Size matters to me. Bob

Bob, are you saying that you don't get different sizes of FishID symbols any more. I don't use it much and may not have used it with 4.020 softqare on the Apex and Solix but I think I had different size symbols the last time I used it.

The problem for me is that I still got lots of symbols and depths for things that weren't fish, like small pods of bait fish... even though it is supposedly based in fish bladder size. I'm just still not a big fan of FishID because it just doesn't seem that accurate.

[SLYDoggie]

Those screen shots are phenomenal. I’ve played around with contrast and sensitivity a lot and get no where near that. I’m not familiar with other settings like water column sensitivity so maybe those types of things will help

Thanks. Water Column Sensitivity will make the biggest difference on fish returns but Dynamic Contrast can be a big help as well. The problem is that Water Column Sensitivity does screw with the bottom and structure returns. I did a test with Water Column Sensitivity at different settings. On the attached screen capture I set it at +3, then 0, and finally at -3 (appeoximately a third of the screen for each). At +3 you get a blow out of the bottom. At 0, it worked as it should. At -3 you get a very jagged bottom. It does seem to be worse when you are running parallel to a steep drop as the attached screen capture was... Bank was on left and 130' of water was on right.

Since I don't care about the bottom or structure returns, this doesn't bother me. I did report it to Hummonbird and was basically told it is what it is so they didn't treat it as a bug.

Edit: I had the shoreline description backwards... the shoreline was on the right and the deep water was on the left. The bottom was hard as well. Hard bottoms do this worse than soft bottoms.

[bobcoy]

My last post was referencing turning off the fish and missing the info provided to me with it on. I do not have many problems identifying baitfish without fish ID and if you leave the fish ID sensitivity at the default (5) you wont get many false fish symbols.(info from Wayne long ago) JMO Bob

[Wayne P.]

My last post was referencing turning off the fish and missing the info provided to me with it on. I do not have many problems identifying baitfish without fish ID and if you leave the fish ID sensitivity at the default (5) you wont get many false fish symbols.(info from Wayne long ago) JMO Bob

Since the air bladder is what determines the FishID symbols, air bubbles in the water will get a symbol also. When Dual Beam was 2D and with 83 kHz having very wide coverage, in cold water, air bubbles coming off the hull bottom would be within its coverage and those would get a symbol also like these in the surface clutter: