I have been approached by a large imaging corporation to possibly use one of my photos for their advertising (which includes displays and handouts) at graphic arts and photographic trade shows. They want, in more or less their own words, "worldwide, perpetual, unrestricted right and license to use, reproduce, distribute, display, publish, modify and sublicense the photo in any manner and through any media whatsoever, including unrestricted use for purpose of publicity, advertising, sales and promotion". In return I am being offered a one-time royalty payment. My questions are : 1. Have I signed over my copyright if I agree? (I am lousy at legal jargon) 2. What would be a reasonable royalty payment? I do not want to undercut the industrial norms and neither do I want to be too greedy. To be honest the fact that they have interest in my photo is satisfaction enough. Any advice to help me go through the deal will be very much appreciated. Thanks a million!