I feel sad. It is an OEM product from Sigma.
Olympus claimed that 4/3 optics is specialized for digital, but it introduce quite a lot Sigma lenses copied from traditional optics.
There're two explanations:
1. Traditional lens is good enough for 4/3
2. Olympus downgrade its standard.
from Fourthirdsphoto.com
http://www.fourthirdsphoto.com/blog/?p=9
Recently a rumor has developed in which some are claiming that the Olympus consumer lenses are being built by another company, some have claimed it could even be Sigma. So when I received the 70-300mm announcement I asked them this question. Here is the response:
Olympus started out as an optical company in the early 1900s.
We were the first to introduce the microscope to Japan in 1920 and also the
first optical device to look inside the human body in 1952, the
gastrocamera.
Prior to launching the E-1 a state of the art facility was built in Asia to
produce our E series optics.
All of the optics in the E system are of our own design. We take a lot of
pride in that point.
Lately, Ive been reading the test comparisons between the kit lenses for
some of the competitive products vs. our kit lenses like the 14-42 and
40-150mm. Seems our consumer kit lenses easily out preform the competition
in the same category.
The quality of the glass is a critical component to the entire system so
its good to know that Olympus doesnt skimp even on those lenses designed
for consumer use.
