Anandtech claimed that they use the old sensor IMX135 while on the hands on videos it's obvious that the LG G3 supports 4K video which only the IMX214 is meant ...
The G3's 13-megapixel rear-facing camera uses the Sony Exmor RS IMX135 image sensor model, includes optical image stabilization and a dual-tone flash, along with a hybrid autofocus system.
LG G3 Beat / LG G3 „s“ ; Front camera effective pixels, 1 megapixels ; Camera sensor type, 1/3-inch CMOS ; Camera digital zoom, Yes ; Camera white balance, Yes.