Thread: Bow Mount sonar unit- SI, DI, 2d, or something else?

Originally Posted by BobB

Since the Helix 10 has 614,400 total pixels.....

I appreciate you answering, forced me to do the research and the math.

I did the same exercise with my 899C HD SI unit. 133 ppi. Interesting, the 899 has more ppi than the Helix 9. However everyone claims the Helix units have better image quality, and based on my Presleys store visits I would agree. I am still digging, both unit are using TFT (thin film transistor) LED screens, see below for technical explanation.

Thin Film Transistor Displays
http://techin.oureverydaylife.com/tf...lay-37558.html
TFTs are a type of active matrix display that controls individual pixel updates several times per second on the screen to update the image relative to the content source. These displays are built from a thin layer of transistors located on the back of the screen that handles screen animation. The display receives information from a computer or video source and updates the screen contents row-by-row so many times per second that it looks like the entire screen is updating content in real-time as opposed to being a collection of frames. A more advanced type of TFT technology called In-Plane-Switching improves the screen viewing angles.

This ties in with Rickies comments. Should give a better image because it has more pixels, regardless of the math used. How/why does the Helix 9 have a better screen image than the 899 when the Helix unit has less ppi and both units are using TFT screens?