I just compared the zf3z camera with that of the iPhone 7 indoors. The iPhone's definitely better, but if you use HDR Pro, the zf3z can get close.
I also own the S7, and in low light its way better than the zf3z.
When using the telephoto in dayl...
There is a link to a rom in this post. In that zip you will find recovery.img. Flash it with adb, like you flashed twrp.
Then you can flash the last M official rom, and subsequently the f...