Woods Creation has created a morphing area-mask tool that parents to the Carrara camera to block out all but a small window of your image. The tool is used to speed up re-rendering when only one small part of a render has changed – especially useful for very large renders and complex scenes with GI calculations. The masked render is then combined with your original full render in a layered photo editing tool like Photoshop. A professional studio time saver!
You can download the free file here.
Update 20170312 (We hope, that´s okay) Since the link is dead, you can find the download now here: http://carraracafe.com/downloads/?did=44