Upload & Sell: Off
It might also be interesting to plot the "service life" (years a given lens was sold/serviced) by focal length. I realize there will be some duplicates (various lens speeds, non-is, V1, V2, etc.). I haven't studied the charts or tables in detail. I guess I would expect the lenses with fewer elements to have a longer service life, all things considered. This isn't strictly a function of focal length of course. The addition of IS to many lenses likely clouds the issue as well. We know from Conurus' work that certain ring USM motors are more failure prone than others. This likely reduces spare parts supplies for certain of the Canon lenses as well.
Looking at the 1991? cluster, it seems clear that 11 or so years later these are all still serviceable at least at CPS Canada. Have any of these lenses been discontinued? One interesting observation is that based on this data focal lengths greater than or equal to 200mm are at greater risk of having service discontinued. We’re looking at 2 each 200mm, 300mm, and 400mm. This is intriguing and suggests a couple of hypothesis: (1) the fewer the copies made, the sooner support will be dropped, and/or (2) something about telephotos make them harder to maintain.
Nice work and much appreciated...Show more →
Edited to add that I echo Robert's appreciation of your efforts Jim!