Instead of using an image plane with emission, it's also possible to have an image as the world background. I may have to show the alternate method's shader node setup, as it's not the most intuitive thing at first. (Would get warped oddly with the default texture space, and some other things too.) Thing about the world lighting is that it comes in from "infinite space", so it may effect the scene a little differently.

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Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.