Help me on scale rate of Layer please ?

Hi. I have a layout size is 896x896 px and window size ( camera size ) is 568x320 px. I want to find a scale rate of layer to set all the background to fit in my window size ( camera size ) 568x320px. I'm following the example "Touch - Zoom " in C2. Normal scale is 1, and scale rate to set all the background to fit in window size around ~0.4, this scale rate is different among devices. I'm using "Scale Outer". Hope someone can help me ? I'm still very new in C2. Thank you

construct will adapt the resolution automatically on every devices, don't worry about that : the only thing that matter is what you see on preview : )

Thank Yapi. I want to make zoom the game as the "Clash of Clan", but it will limit the minimum of scale if all the background was in the screen.

It seems you start with an ambitious project! you'll see that simplest games are often better, because bigger games are almost every time too hard or too long to develop.

Trying something complicated and new is always a good experience, but don't expect too much from your game.

Players from my game requested me to make it >.< I can't refuse it. People can do it, so we are.

what games have you already developed?

sorry if you are more experimented than I thought

My first game named "Ty Phu Chess" on Android and iOS. I put everything learned from C2 in that project.

I limited the scale rate in some ways. But I meet another problem about aligning the layout( or layer ) of zooming in the center of the screen. Hope someone can help me ! I uploaded the capx as well.

Here my capx : https://www.dropbox.com/s/x7yab7btwa5j3y2/zooming.capx?dl=0

And the new post of this issue:https://www.scirra.com/forum/viewtopic.php?f=147&t=150872

Thank for helps.