Fall off skylight shadow faster?

Is there a way to have the the skylight shadows fall off (taper) faster (over less distance)? I would find this useful as I’m pasting the renderings onto a page with a white background and unless I put in a large image with lots of border, I end up seeing a sharp transition from shadow to white background as in the image below.

Thanks,
Sam

You could try using rectangular lights to control soft lighting.

Thanks Nathan, will give this a try.

Sam