When applying seismic interferometry to image sub-vertical salt flanks or structures with large dips from vertical or deviated wells, we are often confronted with poor target illumination. Strong directionalillumination footprints caused by non-ideal placement of sources at the surface degrade the interferometric image quality and may prevent the retrieval of particular dips in the image. The effect of the well's orientation on the interferometric image is investigated. Moreover, a method is presented to estimate the imageable dips in an interferometric image, which can be used to design a more favorable shooting geometry and to gain additional knowledge about the target structures.