How do I add a shadow to Crop Circle?

[enterb]

Hey, I’m looking for an effect between 360: Equirectangular Mask and Crop: Circle.
I’d like to have the edges of my video covered with a circle which is what Crop: Circle does but how do I make this circle shadowed? I don’t want these edges to be that sharp.
Is it possible to add a little bit of blur to this circle?
Thanks in advance!

[Elusien]

Do the following:

• Apply a Mask: Simple Shape filter, choosing “ellipse”;
• Apply an Invert Colours filter, this lets you easily see alterations in the size of the mask;
• Apply the Mask: Apply filter;
• Manipulate the mask’s width and height to match the crop circle;
• Add a second Mask: Simple Shape filter immediately after the first one, choosing ellipse, but change the Operation parameter from Overwrite to Subtract.
• Manipulate this second mask’s width and height to create a “doughnut” (torus) effect.
• Add a Blur: Gaissian filter immediately after the Invert Colors and delete, or switch off, the Invert Colors filter.
• Play with the various parameters of the filters to tailor the effect you want.

See the image below for how your filters should look:

This shows the result with the Blur: Gaussian switched off and the Invert Colours switched on, so you can more easily tailor the extent of the masks’ effect.