rendering problems in zbrush

beartraps

I want to make a nice render in Zbrush and I keep getting uber-pixelated results. From what I understand I am supposed to first, set my document size to a larger size about 4000 pixels wide, then press AAhalf on the right viewport and then export under the document window. I must be missing something because these are the results i'm getting:

OpethRockr55

Looks like you didn't redraw the model onto the canvas. Whenever you change the resolution of the canvas, ZBrush automatically drops everything to the canvas. Hit Ctrl + N to clear it off and draw the new one on in its place.

beartraps

ah ok, the resolution is much better now, however I cant draw the model onto the canvas the way i originally placed it to be rendered. Is there a way to do this?

EDIT: n/m i just zoomed out and used the MSR tools. Thanks for your help!