You may remember my complaint about RAW shooting a cell tower 1/2 mile away and getting blurry images, esp. at 100% in ACR using cheap Sigma glass. Well, I repeated the experiment using a Canon 17-85 f/4-5.5 IS on my Rebel xti. It was like the lights were turned on. Throughout the setting range, the Canon stayed clear to well over 100%. Pixelating, that had occured at 200% with the Sigma, didn't occur until 400% with the Canon glass.
Can this problem be fixed except by pouring more dollars into the glass, I'm trying to avoid buying the Canon 70-300 f/4-5.6 IS as well as the one listed above?