Originally Posted by Scheelings
I'm using a Leica M8. So Actually I was weighing up whether to get the 1.5 Sonnar or the 2.0 Planar. Half a stop doesn't sound like much to give up if more of my shots are going to be as tack sharp as I would expect from Zeiss....
Maybe I need to research some planar vs sonnar threads.
Is there much difference with Bokeh?
So with a Sonnar on an M8 the center of sharp focus can and will be different from what your rangefinder tells you it is. This can be dealt with -- it's just a matter of having an idea of how your lens behaves at various apertures and distances.
But these are very different lenses and if you're considering the Sonnar just for the extra half stop then probably you'd be happier with the Planar. It is a sharper lens, it vignettes less, it is more neutral. The Sonnar imparts a color of its own, yes, the bokeh is significantly different from the Planar, also contrast, field illumination &c. Apologies for the obvious advice, but if you're on the fence you really should do a tag search on flickr for both lenses because the best reason to get a Sonnar is that you like the Sonnar look and to understand it you should see it.