  Self-seeding is a promising approach to significantly narrow the SASE
bandwidth of XFELs to produce nearly transform-limited pulses. The development
of such schemes in the soft X-ray wavelength range necessarily involves
gratings as dispersive elements. These introduce, in general, a pulse-front
tilt, which is directly proportional to the angular dispersion. Pulse-front
tilt may easily lead to a seed signal decrease by a factor two or more.
Suggestions on how to minimize the pulse-front tilt effect in the self-seeding
setup are given.
