The Dawes limit for a 130 mm telescope at say, 6000 Angstrom is 6e-7/130e-3=4e-6 radians or 4e-6*180/pi=240e-6 degrees or 240e-6*3600=1".? An RMS of 0.7" would be fine for that.? A 12"=300 mm SCT has a Dawes limit of 130/300=0.25 of the above which is 0.25" so 0.7 is not good enough.
