Figure 4. Representative images from 20S proteasome datasets acquired with and without a phase plate.

(A) In-focus image acquired with the Volta phase plate. (B) Power spectrum of the image in (A). The presence of the amorphous ice ring at 3.7 Å indicates that there is good information transfer to at least that spatial frequency. (C) Conventional defocus image at −1.6 μm defocus. (D) Power spectrum of the image in (C) showing CTF Thon rings. Scale bar: 50 nm.

DOI: http://dx.doi.org/10.7554/eLife.13046.006