Planar best lens ? in Accessories Posted November 24, 2000 OK. I've done a bit of research, and it appears that the word should actually be 'Bo-ke', pronounced as in 'spoken', so why we westerners put an 'H' on the end is anyone's guess.<br>This business about spherical aberration doesn't really hold water, especially when bad boke is attributed to 'over-corrected' spherical aberration. No lens worthy of the name has first order over-corrected spherical aberration. Any over correction would be in the Seidel 3rd order, or 5th order zonal corrections, which are of very low magnitude.<br>I find it hard to believe that these tiny errors can make a visible difference to an out of focus blob several millimetres across. Furthermore, since these are zonal errors, it should be easy to test the hypothesis by simply stopping the lens down and seeing if the character of the boke changed significantly.<br>A more likely explanation, to my mind, is whether the iris is positioned absolutely correctly at the optical centre of the lens. This position is well known to be critical to the geometrical rendering of the lens.<p>Anyhow, for the last 150 years, both photography and photographers have got on quite well without concerning themselves over 'boke'. I doubt that any of the world's great photographers will find themselves demoted because they used the wrong lens.<br>It also seems strange that the Japanese should concern themselves with this phenomenon, but not be able to control it in their lenses.
Planar best lens ?
in Accessories
Posted
OK. I've done a bit of research, and it appears that the word should
actually be 'Bo-ke', pronounced as in 'spoken', so why we westerners
put an 'H' on the end is anyone's guess.<br>This business about
spherical aberration doesn't really hold water, especially when
bad boke is attributed to 'over-corrected' spherical aberration. No
lens worthy of the name has first order over-corrected spherical
aberration. Any over correction would be in the Seidel 3rd order, or
5th order zonal corrections, which are of very low magnitude.<br>I
find it hard to believe that these tiny errors can make a visible
difference to an out of focus blob several millimetres across.
Furthermore, since these are zonal errors, it should be easy to test
the hypothesis by simply stopping the lens down and seeing if the
character of the boke changed significantly.<br>A more likely
explanation, to my mind, is whether the iris is positioned absolutely
correctly at the optical centre of the lens. This position is well
known to be critical to the geometrical rendering of the
lens.<p>Anyhow, for the last 150 years, both photography and
photographers have got on quite well without concerning themselves
over 'boke'. I doubt that any of the world's great photographers will
find themselves demoted because they used the wrong lens.<br>It also
seems strange that the Japanese should concern themselves with this
phenomenon, but not be able to control it in their lenses.