Opticallimits

... it offers manual focusing ... by wire.

Not that surprising given the 18-135 STM is similarly afflicted?

[quote name='popo' timestamp='1340646105' post='19098']

Not that surprising given the 18-135 STM is similarly afflicted?

[/quote]



It was news to me that STM mean by-wire.

Personally I never had issues with this approach anyway.

[quote name='Klaus' timestamp='1340646426' post='19099']

It was news to me that STM mean by-wire.

Personally I never had issues with this approach anyway.

[/quote]



The MTF curve is ... interesting.

Now I'm interested what an "interesting" MFT means...



There's a spatial MTF plot here although I wouldn't dare try to compare the scale with those here <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' />

[quote name='Klaus' timestamp='1340646426' post='19099']

It was news to me that STM mean by-wire.

Personally I never had issues with this approach anyway.

[/quote]



Lenses with a stepper motor ("STM" means "stepper motor") have no clutch nor reduction gear to avoid any play which would perturb the functioning of the contrast detection autofocus. So you can't expect actioning the helical mechanically.

[quote name='Klaus' timestamp='1340647264' post='19101']

The MTF curve is ... interesting.

[/quote]



I wouldn't say that the bokeh is superb based on the first tests.