DOF in cycle render shows in solid view but not in render Hi I'm rather new to blender and have seen a lot of tutorials now on Youtube and done a thorough research here on the topic Depth of Field. I also created the first renders but have a problem applying depth of field.

I inserted an empty object called FocusPoint and set up the camera details with focus on FocusPoint and an aperture of 5.6. When switching on DOF for viewport in the properties panel under shading I see a DOF in camera view with solid texture. When switching to rendered preview or when rendering with F12 the DOF is not visible. BTW also when changing the aperture afterwards nothing changes also in solid view.

All the tutorials on applying DOF do just the same but it seems to work for them. I am using Cycles Render.

I don't understand what I didn't get. Do I need to do another customization?

I have stripped down the file to just a box and set the FocusPoint to the upper front edge.
Here is the screen showing both views: 
The blend file lies here
In your case i recommend you to change F-stop to radius in the "Aperture" settings. You'll immediately see the blur.  

BUT!

Firstly, you should invert your normals: --> ctrl-n
Youl'll find that's working correct.

Secondly, learn blender basics before doing experiments.