In article , Alfred
Molon wrote:

.. as opposed to the very expensive Olympus lenses which don't even have
IS?

Which Olympus lenses are more expensive than equivalent Canon lenses
with IS?

since 4/3rds has a smaller sensor, to match depth of field as well as
noise, an f/2 4/3rds lens is equivalent to f/2.8 on dx and f/4 on full
frame, all things being equal. thus, the canon 70-200mm f/4 would give
the same final image, and it is about half the price of the olympus.
the f/2.8, which is effectively faster than the olympus lens given the
difference in frame size, is *still* less expensive.

olympus 35-100mm f/2, $2199
http://www.bhphotovideo.com/c/produc...261012_35_100m
m_f_2_0_ED_Zuiko.html

canon 70-200mm f/4, $1059
http://www.bhphotovideo.com/c/produc...58B002_70_200m
m_f_4L_IS_USM.html

canon 70-200mm f/2.8, $1699
http://www.bhphotovideo.com/c/produc...42A002_70_200m
m_f_2_8L_IS_USM.html

nikon 70-200mm f/2.8, $1624
http://www.bhphotovideo.com/c/produc...39_70_200mm_f_
2_8D_VR_G_AFS.html