The controls below this image should allow you to try and correct for astigmatism (i.e. azimuthal focus-variation using the δf controls) as well as to optimize focus (over/under). Try optimizing the focus settings in this sense as best you can.
Parameters describing your final result can be revealed by hitting the "snapshot parameter values" button below. For a new random initial setting (or if the image above is blank), reload this page. Then see how close (on average) you in practice get to Scherzer-defocus (at -561±0 Å) with no more than say 60 clicks of those adjustment buttons after a page reload.
How much does the image that you prefer on average vary from the Scherzer-defocus value? It's possible for example that you prefer a sharper image i.e. one with higher spatial frequencies, which may e.g. be found at a considerably deeper underfocus value than the value with continuous contrast-transfer (and hence a first CTF zero) out as far as possible. To see what an image with corrected astigmatism might look like, hop over to our simulator test canvas here.