Quote Originally Posted by barba


What more would you want a 1.4x extender to do?
<div style="clear: both;"]</div>


The current EF Extenders have a tendency to introduce lateral chromatic aberration in the corners because they don't have any special-dispersion glass or fluorite. A Mark III revision could introduce UD elements and improve the performance in the corners. At present the 1.4x II is quite good in the center, less so in the corners; the 2x II does not impress me at all.