I was wondering if this patient thing was accurate (I really don't know,
that's why I ask). Did Pentax hold the "major" patients, or just a mnor part
of it? Were Canon & Nikon using Pentax "IS/VR" technology"? Or are we just
trying to make us Pentaxens felt better? I have never heard or read the same
suggestion anywhere else outside PDML. Any direct link to any creditable
source to prove this suggestion?
Alan Chan
http://www.pbase.com/wlachan
I believe "in lens" IS is far more complex. Typically, an IS lens has twice
the number of lens elements than comparable lenses without IS. All the
glass is needed to compensate the various aberations introduced by the
moving elements (incidentally the Pentax patents on IS lens design, refered
to by both Canon and Nikon in their IS patents, explains this in detail).
Hence an IS lens is optically compromised. Although some IS lenses are
great the fact is that the same lens would have been even better without
the IS feature. In addition the complexities means that the lenses are more
delicate and will also display relatively large sample to sample variation.
The later aspect is very common for eg. the Canon 100-400 and 400 DO lenses
where several byuers have returned their lenses or exchanged them with
better samples. Some have even given up on them completely.
