100-400mm +1.4x extender IQ

[mfrancis57204]

I recently bought Canon's 1.4x extender to go with my old version Canon 100-400mm f/4.5-5.6L IS Lens and 7D Mk II body. The combo does AF although it's quite slow and only the centre AF point can be used. I expected this so no complaints there. What I did not expected was the staggering drop in image quality. I'm pretty certain cropping an image taken without the extender will give me much better image quality than with it on. In addition I would not be restricted on the use of AF points and AF would be considerably faster Would love to know if anyone has any experience with this combination. Thanks

[jrhoffman75]

http://www.canonrumors.com/forum/index.php?topic=23300.0

[ebiggs1]

I have tried to use that combo a few times and come to the conclusion, it won't fly Orville!  The 100-400 version 1 just doesn't have the IQ to give up to the tele converter.

In general I don't like tele converters, however, there are a few lenses that do work well with one. The first 100-400mm just isn't one of them

[mfrancis57204]

Thanks for the link. I wish had read all this before buying the extender 🙂

[mfrancis57204]

Thanks. I have realized that now