today i search from youtube, and i learn layer. i follow the youtube but i not really understand y can be like that.
first step is i choose a photo, i a photo of flower.

after that i duplicate layer.

and i hide the eye icon.

after that i go image - adjustment and then go black and white.
then adjust the red into 8%.

the next step is use the eraser to erase the leave

then the leave turn black.

Final it present this!!
i redo it many time finally done.....^^