Nikon D1X has a
5.0MP APS-C (23.7 x 15.5 mm ) sized CCD sensor . On the other hand, Fujifilm S3 Pro has a
6.0MP APS-C (23 x 15.5 mm ) sized CCD sensor .
Below you can see the D1X and S3 Pro sensor size comparison.
Nikon D1X and Fujifilm S3 Pro have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.