... Despite the wide spread use of the terms MTF, CTF, limiting resolution, minimum resolvable target, and contrast to describe CCD image system quality, the terms are often misused and their relations are little understood. ... The modulation transfer function (MTF) is a Fourier transform of the line spread function i.e. its equivalent as an integral sum of sine waves taken over the whole range of spatial frequencies. MTF by its Fourier nature can only be used to operate on sinusoidal frequencies. ...

... Printed in U.S.A. AN EXTRA LONG X-RAY PLATEAU IN A GAMMA-RAY BURST AND THE SPINAR PARADIGM V. Lipunov1, 2, 3 and E. Gorbovskoy 1, 2, 3 Received 2007 May 3; accepted 2007 June 25; published 2007 August 6 ABSTRACT The recently discovered gamma-ray burst GRB 070110 displayed an extraordinar y X-ray afterglow with Xray radiation--i.e., an X-ray ... 2006; Wang & Meszaros 2007). ... It is followed by a slow collapse (the magnetic field is weak), which results in a weak X-ray burst. ...