Has any one looked at the ability of Leica lenses to keep out of focus highlights orderly and compact. After examining many slides shot thru good Canon, Nikon and Leica glass, I have noticed a consistent difference in the way out of focus highlights are rendered. My Canon L and Nikon pro-zooms seem to magnify and distort out of focus highlights to the detriment of in focus picture elements. Has any one else observed this?

-- Pedro Lastra (plastra@bellsouth.net), May 17, 2000

Answers

Do a web search for "bokeh" and you'll find out more than you ever wanted to know :-)

-- Michael Darnton (mdarnton@hotmail.com), May 17, 2000.

Pedro

This bokeh business is beaten to death in photonet. However, I think it fair to say that Leica lenses are generally thought to have very good bokeh characteristics- perhaps the older generations might have even better bokeh than the current crop. Zoom lenses generally give the "worst" bokeh compared to any prime. I suspect this is due to the complexity of their optical designs. A symmetrically arranged lens is often thought to give inherently nice bokeh (a double gauss type of design, for example). The Japanese are thought to obsess over the number of blades in an aperture on the assumption that the more there are makes for a more perfectly circular diaphragm and therefore better bokeh.

Certainly I do agree that this is an important characteristic of a good lens, but the problem is that there is no way to accurately characterize it in my opinion, nor really to grade it. We might agree that a lens has "bad" bokeh and another has "good", but graduations in between are difficult. Also so much deopends on the aperture selected, and the distance of the object in focus and the background distance and so on. Basically we know what it is and we know what we don't like, but I doubt whether there are really any meaningful comparisons between say Leica and Canon bokeh that compares truly like with like.

From my own experience I think that 35-100mm primes are the lenses that show the nicest bokeh.

-- Robin Smith (rsmith@springer-ny.com), May 17, 2000.