Perfect quality for "100-400er lens camera" :)

To save weight compared to the Canon 5D and still use both a good image sensor as well as the L lenses Canon EF 100-400mm to L IS USM lens (77mm filter thread) more often, we bought this adapter. Specifically, the combination of this with the small 100-400er EOS M is rather a handy "lens camera". The operation is of course problematic in this extreme, not succeed all the images as desired and the focus assist light comes barely past the lens. In any case, the mechanical quality even with this lens 1400g perfect yet.