I am using cisTEM to process some negative-stain images. FindCTF had a hard time to determine the CTF for all the images. Based on each run's results, I tried different parameters, with a focus on MinRes and Search Defocus Step. However, several images show some confusing CTF corrections.
1) In Image_1, the CTF is not able to be identified. Compared to Image_2, they have a similar 1D CTF FIT result. But the CTF is able to be determined in Image_2.
2) In Image_3, I am not sure why the FindCTF failed. Is it because of the astimagtism (The angle is -51.61)?
I also did the CTF determination for cryo-images. The results are pretty good with a default setting. Is the CTFFIND4 algorighm more suitable for cyro samples?