This question already has an answer here:
I'm rendering some simple 3d shapes to an isometric perspective (orthographic cameras etc) using the Blender internal.
The render is lightning fast so I dragged out another 3d view so Blender is divided into two 3d Views, one on the left one on the right. (Properties editor is on the far right as usual).
When I press F12, initially Blender displayed the render result on the right hand view. This was great as I could make small changes to the camera (on the left) and immediately see changes in the full render just by pressing F12 again.
However every so often when I press F12, Blender seems to randomly decide to put the render result in the left hand view and the right view now returns to the 3d View.
This a a real pain as I then have to re-open the tool and information panels and select the camera again etc. It then also happens in reverse after a while (right now I'm rendering to the right window again).
I thought it may depend on which view I last selected an object in, but in my testing it seems to make no difference.
Does anyone know how I can lock the render result to a specific 3d view when there are multiple 3d views visible?