Film
Filter Size
Due to limited resolution of images and computer screens, pixel filters are needed to avoid Aliasing. This is achieved by slightly blurring the image to soften edges.
This Setting controls home much the image is softened; lower values give more crisp renders, higher values are softer and reduce aliasing.
Transparent
Render the background transparent, for compositing the image over another background after rendering.
Overscan
Percentage of the render size to add to the internal render buffer. This will have a serious impact on performance but can fix render glitches around the perimeter of the rendered image.