Atmospheric seeing reduces any telescope's resolving power to 0.5 arcseconds at best. The seeing conditions at this level are few and far between. Usually the seeing conditions reduce a telescope's resolving power to around 3.0 arcseconds The AO-7 Adaptive Optics Accessory can improve the telescope's resolving power to 0.7 arcseconds. as long as the sky can be seen.
Less than the best, but much more than the usual. Only the giant ground based telescopes with LASER Tracking Beams and very rapid Shape Shifting Mirrors can improve a telescope's resolving power to the limit provided by the Main Mirror's aperture.