Just bought Canon R on a learning curve went out yesterday shot a few pics in RAW was very close to birds zoomed in all the way and the birds were still small and not detailed in the pic? The pics had all the surrounding background not zoomed in on bird only? All were shot in AF.
Did you perhaps zoom in on the LCD screen? If so, that won't zoom in like a lens does; it's simply a tool to view detailed information in an image, or to see if focus has been achieved.
What lens are you using? About how far away were you from the birds?