kosin wrote:
Here is an interesting post I found on naturscapes.net:
ahazeghi wrote:
\"So the controlled tests reveal that the sharpness/contrast is unchanged for extender 1.4X III compared to 1.4X II at all aperture settings when used with original 500/600 IS lenses. The CA has been practically eliminated with the extender III compared to II and is now only limited to residual CA from the lens itself which is hardly noticeable...\"
there is still a big question running in my mind about this conclusion: How can you modify the extender glass construction and claim to have an impact on some lenses but not others of the same focal?
I understand for the focus speed as it is related to new electronics, but changing your glass recipe must not have an impact on all lenses? This questioning has nothing to do with my observation as they were not done in a perfect environment and process. But still, that keeps me thinking...
kosin wrote:
Here is an interesting post I found on naturscapes.net:
ahazeghi wrote:
\"So the controlled tests reveal that the sharpness/contrast is unchanged for extender 1.4X III compared to 1.4X II at all aperture settings when used with original 500/600 IS lenses. The CA has been practically eliminated with the extender III compared to II and is now only limited to residual CA from the lens itself which is hardly noticeable...\"
there is still a big question running in my mind about this conclusion: How can you modify the lens construction and claim to have an impact on some lenses but not others of the same focal?
I understand for the focus speed as it is related to new electronics, but changing your glass recipe must not have an impact on all lenses? This questioning has nothing to do with my observation as they were not done in a perfect environment and process. But still, that keeps me thinking...
JD
Dec 28, 2010 at 11:59 AM
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