Canon Extender 1.4x & 2x ISO 12233 samples crops
have been added to the Canon EF 200mm f/2.0L IS USM Lens Review
. The Extender III samples are the two longest focal lengths available for this lens on the Canon EOS-1Ds III
. The first link is to a mouseover comparison between the 1.4x II and 1.4x III.
Notice that the 1.4x III has less barrel distortion than the 1.4x II. This makes the center-of-the-frame details slightly smaller in a comparison. This difference will be most noticeable in the top crop shown in the ISO 12233 chart tool.
Noticeable in the bottom crop is the reduced CA (Chromatic Aberration) in the 1.4x Extender III.
The Extender 2x III is slightly sharper than the Extender 2x II, but the Extender 1.4x III is not significantly different than the Extender 1.4x II in this regard.