In contrast, a grazing incidence telescope with just one parabolic mirror could focus X-rays, but only very close to the centre of the field of view as it would suffer from extreme coma.
Sebaliknya, teleskop grazing incidence dengan hanya satu parabola cermin bisa fokus X-ray, tetapi hanya sangat dekat dengan pusat bidang pandang seperti itu akan menderita koma ekstrem.