|TF L||[Transfer Function - Generate CTF, in doc file]|
|TF||[Transfer Function - Generate image showing effect of defocus on CTF]|
|TF CT||[Transfer Function - Generate a binary, phase flipping, complex, CTF correction image]|
|TF CTS||[Transfer Function - CTF correction with SNR, image/volume]|
.SPHERICAL ABBERATION CS [mm]: 2.0
[Enter the spherical aberration coefficient.]
.DEFOCUS [A], ELECTRON VOLTAGE [Kev]: 20000, 300
[Enter the amount of defocus, in Angstroms. Positive values correspond to underfocus (the preferred region); negative values correspond to overfocus. Next, enter the energy of the electrons in Kev.
(Note: operation still accepts the legacy input of electron wavelength lambda [A] instead of voltage)].
.NUMBER OF SPATIAL FREQUENCY POINTS: 128
[Enter the length of the 1D array. This is the size of the square image that will be CTF corrected.]
.PIXEL SIZE [A]: 2.8
[Enter the number of Angstroms per pixel in the digitized micrograph.]
.SOURCE SIZE [1/A], DEFOCUS SPREAD [A]: 0.005, 0
[Enter the size of the illumination source in reciprocal Angstroms. This is the size of the source as it appears in the back focal plane of the objective lens. A small value results in high coherence; a large value, low coherence.
Enter the estimated magnitude of the defocus spread corresponding to energy spread and lens current fluctuations.]
.AMPL CONTRAST RATIO [0-1], GAUSSIAN ENVELOPE HALFWIDTH: 0.1, 0.15
[Enter the ACR and the GEH. The Gaussian envelope parameter specifies the 2 sigma level of the Gaussian (see note 2 for details).]