I just did a geographic transformation of an orthophoto using the project raster tool in ArcGIS. The output file has a dark shadow around it that is offset from the image by about 20 degrees. Does anybody know what this shadow is?

1 Answer 1


It's the Null values filling the raster extent. As you've said, you raster image was rotated, but since all rasters must be orthogonal, and their cells must conform to a column and row grid, this results in null, or no-data cells in the edges, filling the gap so to speak, between the image with values, and the raster extent.

GIS programs usually display them as black, though you can set them to clear, or any other color.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.