Canon 100-400 manufacturing date

[chrisb]

Bob, I have a 100-400 with a manufacturing date of UT0313 which supposedly means it's been manufactured in 2005.  My questions is:  do you think Canon uses the latest USM and electronic control technology to make the lens better every so many years?  Do you think they would have put the latest USM motorization and controls in the 2009 and 2010 manufactured lenses?

[Bob Atkins]

I don't think Canon significantly improve their lenses without announcing it. If they make changes to the optics or the IS system, they'd call the lens a "MkII" and they'd probably increase the price!

I suppose they might make very subtle changes or maybe tighten quality control as the years go by, but probably nothing that would really change the performance of a lens.

I have tested two samples of the 100-400. One was maybe 10 or more years ago and the other was a couple of years ago. The newer lens did seem to perform slightly better, but then you can't tell much from just two samples and if you tested two samples made last week it wouldn't be a surprise to find that one was slightly better than the other due to manufacturing tolerances.

Given the age of the lens (introduced in 1998), a 2005 model probably counts as relatively new. If there were any initial problems they would have been ironed out by 2005.