I did this test - took one pic with the lens on back closest to flash taped up, and one pic with both lenses uncovered. Only visible difference is the file size.
Color pic [Broken mode (must mean Bokeh in China...)]: both lenses 1.36 MB / one lens covered 1.39 MB.
Mono pic: both lenses 2.31 MB / one lens covered 2.61 MB. Haven't tried it on selfie cams.
The pictures are EXACTLY the same as you view them on the screen! Can't see ANY difference whatsoever...
Video @ https://youtu.be/MZTKlJO-55I
This is not surprising as MT6580 only has one ISP, and therefore only can control one camera at a time...
So what I wonder is:
WHAT does the secondary 0.3 Mpix cam DO???
Does it just sit there?
Also:
You can't move the focus point in Mono mode.
It's fixed to the center of the screen.
The JPEG compression is a little harsh.
The screen is too dark to use the camera comfortably outdoors in sunny weather, unfortunately.
But if you only want to use it indoors, it's OK.
Other than that: the finger print sensor works OK, Android 7 is OK.
I do not complain, you get what you pay for.
And also I got to learn about Image Signal Processors.
But a little more honesty in marketing would he appreciated...
So if you want a REAL dual camera phone, it MUST have at least two ISP's on the SOC! Check the specs!