When setting the field of view in Hugin via the preview window, the restitch and remap of the images takes a fair bit of time when the panorama consists of many high resolution images. This can make the process of finding an acceptable FOV frustrating. One way to speed up this process is to disable all images except for those at the boundary. This way each update involves relatively few images and you get more responsive feedback.
For example, if the panorama is a long strip, then you only need to enable the image at the start and the end of the strip.
Cheers,
Steve