ive found my 85 1.2 pretty sharp at 1.2 in the center, it just has a slight difusion blur over the top of the sharp detail (does that make sense?).[a href=\"index.php?act=findpost&pid=137752\"][{POST_SNAPBACK}][/a]
Yes. That's a euphemistic way of saying 'not sharp' . It's not sharp, but hey! I like it. My lens has become a 'soft focus' lens; ideal for portraiture and keeping those skin blemishes down.
There has been a lot of discussion of DoF issues on this forum over the years, some folks insisting that DoF is affected only by the FL of the lens, aperture and distance to the subject. My own view is that it is also affected by the sharpness of the lens at the plane of focus and
this factor is very difficult to incorporate into the DoF formulas.
For example, the 85/1.2 at f2 on 35mm should have the same DoF as the Z110/2.8 at f2.8 on the Aptus 75 (at same distance to subject). The background blur should be very similar in both cases, allowing for differences in bokeh between the two lenses. However, if the Z110 is as sharp or sharper at f2.8 (MTF wise) as the Canon 85/1.2 at f2, then the shot from the 33mp Leaf with a 48x36mm sensor will be perceptibly sharper at the plane of focus.
The backgrounds of both shots should be equally blurred, but the points of focus will be sharper in the MF shot, hence a sense of greater 3-dimensionality. Stopping up with the Canon lens to f1.4 or f1.2 will not solve the problem. The background will then become more out-of-focus and more unrecognisable and the plane of focus will also become more blurred due to the lower MTF of the lens at wider apertures.
